close

Вход

Забыли?

вход по аккаунту

?

Патент USA US2403603

код для вставки
July 9, 1946.
2,403,603
A. KORN
WIRELESS COMMUNICATION
Filed Feb. 5, 1941
I 13
‘0
5 Sheets-Sheet l
I6
lo'
/
5|
PLANE I
|3000 FEET
ALTITUDE
|2500 FEET
PLANE 2
Aurrrups
FIC-3.2¢
ARTHUR KORN
July 9, 1946.
A. KORN
2,403,603
WIRELESS COMMUNICATION
Filed Feb. 5, 1941
Ow
mw
5 Sheets-Sheetv 2
mOFUJm»alma
am..
«2u.530.
m„no. .
INVENTOR
ARTHUR KORN
AL, ATTORNEY`
July 9, 1946.
A. KORN
2,403,603
WIRELESS COMMUNICATION
Filed Feb. 5,i 1941
5 Sheets-Sheet 3
IlrLI.
ON
IKNvENToà
_
ARTHUR KORN
m5
l 16am/la.
al@ ATrQRNEY
July 9, 1946.
A. KORN
2,403,603
` WIRELESS COMMUNICATION
Filed Febfä, 1941
5 'sheets-sheet 4 -
INVENTOR.
BY
MMM/Km»
July 9, 1946.
2,403,603
A. KORN
WIRELESS COMMUNICATION
Filed Feb. 5, 1941
5 Sheets-Shèei’l 5 ~
-OFUmJwTl
I
<„1l|
_l
I
N
p'î
- mvENToR
ARTHUR KORN
L..
BY Qx
l
‘l
»QM
aMATroRm-:v A
,
Patented July 9, 1946
_ 2,403,603 1
PATENT' oFFlci;-
UNITED STATES
2,403,603
WIRELESS COMUNICATION
Arthur Korn, Hoboken, N. J., assignor to Square D
Company, Detroit, Mich., a corporation _of
Michigan
Application February 5, 1941, Serial No. 377,516
21 claims.
l
2
This invention relates to a method of, and ap
paratus for, wireless communication, more par
“ticular1y.designed for communication with and
between aircraft.
.
matically scanning a. band of carrier frequen
cies in dependence on the altitude of the receiv
ing craft and indicating the presence of other
craft in the proximity by indicating their rela
~
It is an object of this invention to provide a 6 tive alütude with respect to the receiving craft
method of, and an apparatus for, wireless com
and, in further development of this invention, in
munication permitting an airplane -in'fiight to
addition, the direction of ñight of such craft.A
More specifically, the invention aims at Dro
communicate to other planes or a station on the
ground Within a predetermined range or dis
tance certain Hight data as, for example, its alti
tude and its direction of flight.
„viding a combined transmitter and receiver for ~ ‘
l0 the continuous transmission of signals represent
ing altitude of a transmitting craft and simul
taneously scanning a band of carrier frequen
It is thus a purpose of the invention to com
municate to the pilot of a plane in flight cer
cies in dependence on the altitude level of the
tain flight information such as altitude or direc
transmitting craft including means for protect- '
tion of flight, or both, of other craft in the vicinity 15 ing the receiver from signals of the transmitter
of the plane in order to eleminate the danger of
with which it is combined.
The invention further aims at improving the
or poor visibility.
above method of, and apparatus for, communi
It is a further purpose of this invention to Pro..
cation by providing steps and means for elimi
vide a method of, and means for, communica 20 natinginterference by stray signals.
tion between an airport operator and planes in
Further aims. objects land advantages of this
the vicinity of the airport giving the airport con
invention will Aappear from a. consideration of
the description which follows with accompany
trol ofñcer visible indication of altitude and di
rection of all planes in the vicinity of the port.
ing drawings showing for purely illustrative pur- '
For carrying out the above objects, the inven 25 poses embodiments of this invention. It is to be
tion more broadly provides a method of com
understood, however, that the description is not
munication for continuously informing a remote . to be taken in a limiting sense, the scope of the _
station of certain data of variable magnitude‘by
invention being defined in the appended claims.
Referring to the drawings:
~
causing the carrier frequency of a radio signal
collision in mid air especially during blind flying
to be changed in response to one variable and, in 30 - Flg.- 1 is a diagrammatic illustration of the
principle of this invention showingtwo airplanes
case of transmission of several variables. t0 cause
the carrier frequency to be modulated in addi
each equipped with a transmitter and a receiver '
tion by one or several modulation frequencies.
according to this invention;
The invention further aims at providing suit
Fig. 2a is a diagram illustrating the signals'
able apparatus for practicing this method. -
35 transmitted by plane I of Fig. 1;
It is thus a further and more specific object of
this invention to provide a transmitter for use
on aircraft including means for changing its car
Fig. 2b is a diagram >illustrating the band of
frequencies covered by the receiver of plane 2 of
Fig. 1:
'
'
rier frequency tuning in response to changes in
Flg. 3 is a block diagram illustrating the oper
altitude, for example by means of an altimeter, 4d ation of a transmitting and receiving unit accord-p ï
and including means for modulating the variable
carrier frequency in response to azlmuthal direc
ing to this invention;
tion, for example by means of a compass or a
trative form of circuit of a transmitter and re
Fig. 4 is a circuit diagram showing an illus
ceiver for altitude signals;
directional gyroscope.
It is a further purpose of the invention to pro 45 Fig. 5 is a perspective view of an' altitude con
vide a receiving apparatus capable of interpret
trolled tuning element of the transmitter and re
' ceiver of Fig. 4:
_
ing such signals.
ÍFig'. 6 is a perspective view of a motor con- The invention thus aims at providing a receiv
ing apparatus capable of scanning a certain band
trolled tuning element of the receiver of Fig.'4;
of carrier frequencies for signals and interpret 50 Fig. 'l is a circuit diagram showing a transmit
ing the carrier frequency of received signals in
ter and receiver for the transmission and recep
„ tion of directional signals; and
‘
terms of the transmitted variable, such as alti
Fig. 8 isa perspective view of a tuning ele
tude.
More particularly, the invention aims at pro
ment of the transmitter shown in Fig. 6.
vidìng a receiving apparatus capable of auto 55
'I_'hc principle of this invention will readily be
2,403,803
understood from the diagrammatic illustration
of Fig. 1. It may be assumed that a ñrst plane
In the illustration the primary tuning elei‘nent
I4' is automatically adjusted by an altitude re
sponsive device represented by an evacuated
aneroid capsule IB'.
plane is in its proximity at an altitude of 12,500
Assuming that a band of frequencies corre
feet. In order to avoid collision between the two
sponding to a range of altitudes of plus/minus
planes, the invention provides a method and
1,000 feet relative to the altitude of the receiving
means whereby the planes may exchange infor
plane is to be scanned for signals, the altitude
mation as to particular night data which will ' responsive
device i6' will tune the receiver Ra
enable each pilot to steer his plane clear of the
10 to the highest frequency of the band. In the
other plane.
illustrated example, the frequency of 49.35 mega
Plane l is shown as equipped with a transmit
cycles corresponds to the altitude of 13,500 feet.
ter T1 and a receiver R1. The transmitter and
A secondary tuning element shown as a vari
receiver of the n_rst plane are provided with an
able condenser i5' is mechanically operated by
tennas i and ll respectively. A tuning element
suitable means such as a motor M' for tuning
in the transmitter Ti which may be a variable
the receiver R2 successively to all frequencies
is at an altitude of 13,000 feet while a second
condenser l2 is controlled by an altitude respon
sive device diagrammatically illustrated as an
A from 49.85 to 49.15 megacycles thereby scanning
the range of altitude from 13,500 to 11,500 feet.
The frequency band is indicated in Fig. 2b by
The dash-dot line in the center of the
transmitter in dependence on the altitude at 20 shading.
shaded band represents the altitude of the second
which the plane l flies.,
plane which is 12,500 feet. The incoming signal
In Fig. 2a there is shown how a band of fre
of the ñrst plane is represented as a series of
quencies may be co-ordinated with a range of
dashes 2 and falls well within the band scanned
altitudes. In the illustrated form of the inven
`
~
tion a band of carrier frequencies extending from 25 by the receiver R2.
As
hereinbefore
stated,
the
instantaneous
48 to 51 megacycles is used to cover altitudes from
tuning of the receiver is dependent upon the
zero to 30,000 feet.
adjustment of the secondary tuning element, for
The transmitter of `the plane I ñying at an
example. the angular position of the rotor plates
altitude of 13,000 feet will, according to the chosen
of the condenser l5'. Therefore, the adjustment
30
coordination of frequencies with altitude, trans
of the secondary tuning element at the instant
mit signals of a frequency of 49.3 megacycles.
of reception of a signal is representative of the
The signals may be transmitted periodically and
altitude of the plane from which the signal
are represented in Fig. 2a by dashes 2 parallel
originates relative to the altitude of the receiving
evacuated aneroid capsule i3. The tuning ele
ment l2 changes the carrier frequency of the
to the time axis.
_
.
These signals are picked up by the second plane 35 plane.
As Will be outlined in greater detail below, an
which is equipped with means for interpretating
indicator may be associated with the movable
the signals in_terms of altitude. This is accom
member of the secondary tuning element, in the
plished by automatically scanning a relatively
illustrated example the rotor plates of the
narrow band of carrier frequencies coordinated
condenser l5', to indicate the altitude of the
40
to the altitude of the receiving plane. For this
transmitting plane relatively to the receiving
purpose a receiver is provided for picking up
plane.
any signals transmitted by planes flying at ap
The scanning of the frequency band corre
proximately the same altitude as the receiving
sponding to the desired/'altitude range relative
plane. As a practical example, the receiver may 45 to the altitude of the receiving plane maym be
be so adjusted as to respond to all signals trans
repeated at any desired number of cycles per
mitted by planes flying within a predetermined
unit oi time.
i
' distance of about five or ten miles and at an alti
I have found it convenient to traverse the
tude differing from the altitude of the receiving
tuning range approximately ten times per second
plane by less than 1,000 feet altitude.
50 which would correspond to «a rate of rotation of
To this end, the receiver of each plane isthe rotor shaft of the condenser l5' of ten revo
equipped with a primary and a secondary tuning
lutions per second, or 600 revolutions per minute.
element. The purpose of the primary tuning ele
An indicator such as a glow lamp operated by
ment is to set the receiver for a carrier fre
the receiver Rz will, accordingly. be actuated ten
quency in dependence on the altitude of the
.55 times per second by- a signal Picked up by the
receiving plane.
The secondary tuning element permits periodic
receiver. l This
arrangement
will
be
further
illustrated in the succeeding detailed ñgures of
scanning of a relatively narrow frequency band
the drawings.
corresponding to the altitude range in which the
From the foregoing it will appear that during
presence of other planes is to be ascertained. In -60 each scanning cycle the receiver will also be
the illustrated embodiment, the altitude range is
tuned to the frequency of the transmitter with
chosen tc extend from plus 1,000 feet to minus
which it is associated in the same plane. Since
1,000 feet with respect to the altitude of the
it is undesirable to pick up a signal from the
receiving plane.
transmitter with which the receiver is associated,
Referring now to Fig. 1 the transmitter and
in other words, since it is undesirable to pick up
receiver of the second plane correspond in all
particulars with the transmitter and receiver of
‘the signal of the transmitter T2 by the receiver
R2 during each tuning cycle, means are provided
for protecting the receiver from signals of the
the~ñrst plane. Primed reference numerals are
associated transmitter.
.
accordingly used for denoting the elements of
Many forms of means and circuits are known
70
the second plane.
in the art of electric communication which may
The transmitter T2 is equipped with a trans
b'e employed for this purpose.
mitting' antenna I0', the receiver R2 includes an
In the embodiment of the invention described
antenna I I’. A primary and a secondary tuning
hereinafter in greater detail, I employ mechani
element is provided for tuning the receiver R2
75 cally operated means for silencing the trans
to the desired frequency.
2,403,603
5
mitter for the period of time during which the
receiver would respond to the signal of the
associated' transmitter.
'
This may conveniently be accomplished by
- 'Finally the ‘received signal vmay be interpreted in
terms ofr volume in_order lao-determine change'in
distance from the'transmitting station.
Referring now -to Fig. 3„ the transmitter T in
means of blanking keys S1 and Si' operated by
cludes a tuning element shown as a variable con
the motors ,M dhd M', respectively, for inter el' denser
I-'2 y for controlling the carrier frequency
rupting the Í„transmitter signals while the
.associated receiver is scanning the frequencies
close lto the transmitter~ frequency.„ This
l of a signal'emitted by the-antenna I D. _ 'I’he‘tun- -
ing element is controlled by an altitude responsive
means ~shown as an> evacuated diaphragm I3.
signals from other planes flying in the vicinity '10 The carrier may be modulatedto give the sig
nal a distinct characteristic. A modulator- Sz for
at-the same altitude.
modulating the carrier frequency is shown in the
The _communication method and system
form of >a rotatable interrupter disk I1 mounted
according to this. invention pe ‘ts simultaneous
on a shaft I8 of a motor 23. The disk Il includes
transmission of several variables to a receiving
insulating sectors 20 and rotates between brushes
station.
arrangement permits undisturbed reception 0f
Illustrating this feature by reference to - a
communication method and system for aircraft,
it is possible to transmit,-in additionto informa
tion regarding altitude, further data, such as
2I and 22 periodically-to interrupt the flow of
current between the same.`
I
Turning -now to the receiver R, an incoming
signal-is pickedr-up by :thefantenna II. The re
as hereinbefore explained, includes apri
direction of flight, or course of the transmitting 20 ceiver,
mary and a secondary tuning'element shown as'
'
I
variable condensers I4 and I5. The condenser I'4
Fig. 3 illustrates in the form of a block
is adjusted in response to altitude by an altitude u
diagram the structure of a device for practicing'
responsive element illustrated as an evacuated
the method for communicating a plurality of
diaphragm capsule IVG. ~
.
variable data.
A_
secondary
tuning
element
shown
as a4 var
Referring ñrst to the method, a signal is
plane.
transmitted and the carrier `frequency of the
signal varied within the limits of a predetermined
bandof carrier frequencies in dependence'on a
first variable, such as altitude in the -pres'ent
specific example,
The carrier may further be modulated by a
predetermined fixed or variable modulating fre
quency. A variable modulation mayßbe` im
pressed on the carrier in response to the azi
muthal direction of the pli-.ne transmitting- the
iable condenser I5 is periodically operatedby the ‘ e
motor 23, a shaft 24 being shown driven over a
gear train 25 from the motor shaft I8. The con
denser I5 is preferably/ of the type in which the
capacity increases gradually during the greater
part ofone revolution andl which after reaching
a maximum capacity may be' brought to its mi'n
imum capacity position by further rotation
through a; relatively small angle.
One form of condenser having this character- '
~ istic is known as a “270°-condenser” and is so~ con
signals. "I'his variation may be cyclic, that is to
structed as to increase its” capacity during 270° of
say, in traversing the entire azimuth circle from
~ rotation of its rotor from a minimum to a maxi
north via east, south and west to north, the
AFurther rotation of the rotor plates
modulating frequency may be caused to increase 40 mum.
through anangle of 90° will restore the condenser
during one-half of the azimuthal circle and be
to the-position of minimum capacity.
caused to decrease again during the other half of
The capacity of the condenser I5 is preferably the circle. For example, there may be caused' an
ladded to that of the condenser I4, thereby chang
increase in frequency from a minimum to a max
ing the tuning of the receiver successively
imum for directions between north and south
through a predetermined band of carrier frequen
through east. The modulation frequency may
cies.
The upper limit oi’A the band is fixed by the
then be decreased again for directions within the
sum of the capacities of condensers I4 and I5
second half of the azimuthal circle including.
when condenser- l5 has its minimum position, the
west.
.
in order to eliminate ambiguity arising from 50 lower limit- by the sum when condenser I5 is at
the cyclic increase and decrease in the- modulation
A signal of a frequency Within the band
maximum capacity.
frequency,
a further and ñxed modulation fre- '
quency may be impressed on the ca_rrier for dl
rections within one-half of the azimuthal circle.
‘I‘his modulation may be of a higher frequency.
No such distinguishing modulation being pro
.
»
,
.
.„ scanned by the receiver R is amplified by an am-l
pliner A and- utilized for actuating an indicator.
The altitude indicator is shown in the illustrated
embodiment :to include _a glow- lamp 26.
.
A band pass filter F1 may be interposed be
vided for the- other half; signals representing east.
tween the amplifier and the indicator to elim
and west-course become distinct although. ac
inate interference. by radioïsignals of :other than
cording to the present example, the variable mod
ulation frequency assigned to west is the same as 60 a predetermined distinguishing frequency. The
filter in the illustrated` embodiment is tuned to
the one assigned to east.
"
the frequency of the modulator Sz, the same dis
The modulated carrier frequency may further
tinguishing
modulating frequency being used' by `
bemodulated, preferably at a relatively low fre-,
all planes.
A
A
.
\
quency, in order to give all transmitted signals a;
During
each
tuning
cycle
a-»received
signal
will
particular characteristic enabling filtering of the
_cause .the glow lamp 26 to light once. 'The glow
signal at a receiving station in order to eliminate
lamp will respond’at the exact moment at which
stray signals or interferences.
`
the >receiver is tuned to the carrier frequency of
A signal formed according to this method may ’ the
particular signal. ' The angular position of >
be interpreted at the receiving station as to the
various data transmitted by the signal. The car 70 the rotor- of the tuning element l5 at theinstant
rier frequency represents one variable, s'uch- as .
altitude. In addition, the received signal may
include further variables such as direction of f
flight represented by modulation frequencies. 475
ofreception of a signal thus becomes a measure
ofthe carrierfrequency of the signal. -Indicat
_ing means are provided for indicating this posi
' tion.
In the 'i'uustratedembodinient a rotatable disk _
2,408,603
Further data. may be transmitted by4v the same
21 is mounted on the'motorshaft I8. The ‘ro
tatable disk carries a marker or pointer 28 which
may be painted thereon to cooperate with the
graduations of a ñxed dial 29 preferably grad
uated in feetof relative altitude'.
The glow lamp‘26 preferably provides the sole
signal by additionally modulating the4 signal in
dependence on such data. In the illustrated form
of the invention, means are providedl for .trans
mitting information regarding the azimuthal di
rection of the Etransmittinf.; plane` by modulating
the signal in response to azimuthal direction.
illumination for vthe indicating means. At the
instant of reception of a signal the glów lamp will
A modulator Ma is shown for this purpose con‘
trolled by a. directional instrument, in the illus
light to render the momentary position of the
'
pointer 28 visible` relatively to the dial. Assum 10 trated embodiment, a compass magnet.
Referring now also to
8. the modulator
ing the rate of` rotation of the rotor shaft to be
includes an inductance coil 35 wound lsubstantial
ten revolutions per second, the lamp 26 will light
ly in the Íforni of a triangle and curved so »that~
its hypotenuse forms a circle .normal -to the
curved area oi the triangle. The coil 35 is acted
upon by a movable mass 38, preferably of iron,
adapted to modify the inductance of the coil.
The mass te is mounted for rotation on .theshaft
ten times during each second giving the appeal’
ance of the pointer 28 to be stationary due to the
resulting stroboscopic eiîect.
The scanning cycle ymay be assumed to begin
at the moment when the condenser I5 is in the
position'of greatest capacity. Since the motor
23 runs at a substantially constant speed, the
» 3l by means or an arm 08. The shaftvßl'is ro
tatable in bearings as and 48. A direction re
spons'ive element shown as a pair of magnets“
mounted on the shaft by means of arms I2 and
scanning cycle is completed within a predeter-I
mined time, for erample, one tenth ot a second
during which the pointer 28 makes a full revó
48 maintains the mass 38 nxedin azimuth. A
lution. The relationship in point of time of the
mass M may be provided to counterbalance the
periodic reception of a signal, also called time
`
"
`
phase of the signal, with respect to a ñxed zero 25 mass 3a.
As the craft turns in azimuth the inductance
point of the scanning cycle, for example the in
will be caused to rotate relatively to the'mass 30
stant at which the condenser l5 assumes its
about the axis of the shaft 31 thus causing the
greatest capacity, thus becomes a measure of the
mass to act on a wider or narrower area.of the
carrier frequency of the signal in the illustrated
arrangement and, accordingly. of the altitude of 30 inductance 85. rll'his movement causes the fre»
the transmitting plane relatively to the receiving
quency of the modulator to increase and decrease
depending on the direction of relative movement.
plane.
.
The device may be so adjusted that the mass
In the illustrated embodiment, the graduation
36 is opposite the narrowest partl of theiinduc
of the indicator is spread over an arc of 270°, a
tance while the craft is headed north. The mass
270° condenser. I5 being used in the receiver R.
will move into a position opposite the widest part
The condenser will be described in greater detail
of the inductance if the craft changes its course
by 180°. This movement will cause the frequency
In the drawing the pointer is shown in a po
of the modulator to decrease from a maximum
sition of plus 400 feet altitude indicating that a
signal is being received from a plane flying l1:00 40 to a minimum. If the craftV continues to turn
in the same direction the modulating frequency
feet higher than the receiving plane.
will again increase to assume al maximum after
Since the condenser l5 after reaching its maxi
the turn of 360° has beencompleted. `
.
mum capacity is rotated further into the posi
The range of modulating frequencies is pref
tion of minimum capacity, the lamp will light
again during the remaining 90° of rotation of 45 erably so selected that it may be covered by one
scale of a frequency meter. A suitable range
the condenser and the indicator. It is for this
would be 500 to 700 cycles.
^
reason advantageous to provide a. blanking sector
The cyclic change in the modulating frequency
30 of 90° covering the marker or pointer 28 dur
entails an ambiguity since the same `modulating
ing the 90° movement from minimum to maxi
frequencies are co-orclinated with either half of
mum capacity of the condenser. The glowing of
the azimuth circle. This ambiguity may be elim
the lamp Z-l during the 90° movement of the con
inated by impressing a further and distinguishing
denser into its position of maximum capacity thus
below.
-
‘
becomes unnoticeable.
.
modulation on the signal during one-half of the
'
It will be noticed that the mark in the center
of the graduation 'represents a. relative altitude 55
azimuth circle.
diiîerence of zero. A signal causing the lamp to
light at this point will be a signal of the same
carrier frequency as the one transmitted by the
transmitter T associated with the receiver. Means
further inductance coil 45 curved as to form a
In the illustrated embodiment this means is
shown in the form of a blanking key Si com
prisingl'a disk ofi conducting material 3i includ
ing an insulating sector 32. The insulating sector
frequency on the carrier »when the azimuth lies
in a chosen half of the azimuth circle herein
chosen to be north to south through east. The
is soïarranged with respect to contact brushes
33 and 34 as to out oiï the transmitter while the
Referring now to the receiver, an indicator may
be provided for indicating the data transmitted
as variations in modulation. frequency. In the
'
In the illustrated embodiment thereis shown a
half cylinder.
The coil is coupled with indlict»Y
ance 35 so that when the iron~ mass 36 is opposite _
the coil 45 there is suiïicient mutual induction to <
are therefore provided for preventing the receiver 60 allow relay fili to .be energized. Relay 48 controls,
a. further modulator S3 shown in the illustrated
from responding to the signals of the transmit
embodiment as including a disk 41 mounted on
ter with which it is associated.
the motor shaft i8 and having alternateconduct
Such means may take the form of a Switch
ingand insulating sectors 48 and 49 respectively.
or other device for rendering the transmitter in
The disk is shown as moving between brushes
operative during the period of time during which
50 and 5l.
'
the receiver would respond to the signal of the
This modulator will impress its characteristic
associated transmitter.
ìiioin'êegr 28 passes thezero mark on the gradua
frequency may be 3,000 cycles.
«»
A
75 illustrated embodiment there is shown‘an indi
D 2,463,603
.
9
_
cator 52 having two pointers 53 and 54 movable
over dials 55 and 56 respectively. The dials bear
frequencies in a manner hereinbefore described.
One-half ofthe indicator dial is rendered visible
at a time, the distinguishing lamp 51 or 56 being
The pointers 53 and 54 are jointly actuated
from the movable element of a frequency meter
lit through the selector relay 59, '
later to be described in greater detail. The fre'
quency meter is connected to the amplifier A of
the receiver R preferably' through a band-pass
ñlter Fn permitting only frequencies of the mod
to move in opposite directions.
'
'
10
azimuth direction co-ordinated to the modulating
directional graduations. eachl dial covering one
half of the azimuth circle.
ulator M2 to pass through, in the illustrated form
of the invention, frequencies between 500 and '700
cycles. 'I'he pointers 53 and 54 are connected
y
frequency of the incoming signal in terms of
10
.
At the same time the receiving` plane transmits
its own altitude by changing the carrier frequency
of the outgoing signals in response to changes in
altitude.
c
,
‘
'l'he receiver associated with the transmitter is
protected Vfrom the outgoing signals through the -
blanking key Si interrupting the transmitter
While the associated receiver is scanning the fre
Means are provided for distinguishing 'between
quencies close to the transmitter frequency, thus
the two halves of the azimuth circle to which
permitting reception of incoming signals of the
equal bands of frequencies are co-ordinated. In
same frequency at which the transmitter `oper
the illustrated embodiment 'of the invention,
ates.
transparent dials are employed lighted by one or
Exact synchronism between communication
the other of a pair of bulbs 51 and 58 selectively 20 sets of different planes is avoided by slight dif
lighted through a selector relay 59. The selec
ferences in the rate of the motor 23. In the ab
tor relay may be combined with a band-pass ñlter
sence of synchronizing means,- the motors 23 of
Fà permitting only frequencies of the distinguish
different planes will operate at slightly din'eren't
ing modulator 41 to pass through, in the illus
speeds preventing a condition to exist -for an ap
trated form of the invention, 3,000 cycles. o
25 preciable length of time in which the transmitter
Information regarding a change in distance of
. of a second plane in the vicinity is silenced exact’-`
a transmitting plane from the receiving plane
1y` during the period of scanning of the frequency
may be obtained by means of a distance indi
band within which the frequency of the trans
cator 60 which may be of the volume responsive
mitter of the second plane lies. Temporary syn
type employed in radio receivers. The distance 30 chronism may thus exist during a few seconds
indicator is shown to be connected to the receiver
only.
.
and includes a pointer 6I movable over adial
In Fig. 4 lthe wiring diagram of a communica
62 preferably graduated in units of distance. A
tion device is shown for transmitting altitude sig
setting marker 63 may be provided, adjustable by
nals. The device includes a transmitter and a,
means of a setting knob 64, to permit an easy
receiver.
'
'
i
reading of a change in volume of an incoming
Referring ñrst to the transmitter, the antenna
signal. After setting into a position opposite
circuit includes a doublet antenna I0 and an in
of the pointer, the movement of the pointer rel
ductance 65. .The antenna coil is coupled with
atively to the setting marker in response to
the
oscillator circuit in a suitable manner, in the
changes in volume of the signal will 'be a meas 40
illustrated
-embodiment there being shown a plate
ure of the change in distance from the trans
inductance 66 and >a. grid inductance 61 onefor
mitting plane. An increase in volume, causing
the pointer to move to the right, therefore indi
cates a decrease in distance, while a movement in
the opposite direction, towards the end ofthe dial,
marked infinite, indicates that a transmitting
plane moves away from the receiving plane.
The operation of the device illustrated- in Fig. 3
is as follows:
‘
The transmitter T transmits a signal, the car
both of which are inductively coupled with the
antenna inductance. The coils 66 and 61 are
connected by blocking condenser 68. The oscil
lator is supplied with energy by a 'thermionic
tube 69_and is controlled :by a suitable tuning ele
ment, there being shown a variable condenser I2 .l n
mechanically connected to an altitude responsive
diaphragm I3. The tuning element I2 changes
50 the carrier frequency of the transmitter in de
rier frequency of which is changedin dependence
pendence on the altitude to which the diaphragm '
on changes in altitude ofthe transmitting plane
I3 responds.
as hereinbefore described.
.
A second plane or station equipped with the
same communication device will pick up the sig
nal with its antenna II. The receiver R of the
receiving station is -tuned to a frequency co-or
dinated to the altitude of the receiving plane and
through its mechanically operated tuning ele
The altitude controlled condenser is shown in
greater detail in Fig. 5. The diaphragm I3 actu
ates the rotor plates 10 of the condenser I2 by '
means of a pinion 1I and a, toothed sector 12 to
which the center piece 13 of the diaphragm is
connected by means of a link 14.
In order to give a distinguishing characteristic
60
to
the altitude signals, the transmitter output
responding to a predetermined altitude band
may be modulated by a characteristic frequency.
above and below the altitude of the receiving
In the illustrated form ofthe transmitter there
plane.
is shown a modulator Sz including the motor
The altitude indicator of the receiving plane is
driven disk I1 having insulating sectors 20 im
`iointly actuated by the received signal and the
bedded therein. The disk is driven by the motor
mechanically operated tuning means to indicate
23 through the shaft I8 and moves between
the carrier frequency of a received signal in terms
brushes 2l and 22 therebyA changing the grid bias
of altitude in a manner hereinbefore described.
of
the'thermionic tube at a suitable frequency
Upon reception of a signal the setting marker 63
which may 'be of the order of about 100 cycles.
of the distance indicator 60 may be set at a posi
'I‘he grid leak may consist oftwo resistances .15
tion opposite of the pointer 6I to determine
and 16. The resistance-15 lies parallel to the
changes in distance of the transmitting plane.
brushes 2l and 22 of the> disk and is short cir
At the same time the azimuthal direction of
cuited periodically to reduce the grid leak to the
motion of the transmitting craft may be read at
value of the resistance ‘Iiil thereby modulating the
the azimuth indicator indicating the modulating
carrier of the transmitter. Preferably resistance
ment I5 scans a band of carrier frequencies cor
aeoaoos
4
l1
12
.
„
i
In Fig. '7 a communicationl‘device is'shown
‘I5 is greater than ‘I8 in order to secure deep mod
ulation.
The transmission of signals is periodically in
terrupted while the associated receiver scans fre
quencies close to the carrier frequency at which
the transmitter operates. For this purpose there
for transmitting in addition to information re
by the plate battery il.
successive conducting and insulating laminations'
garding altitude further information Vregarding
the course of ithe airplane. The transmitter
circuit is similar to the one described in Fig.
4 except for the provision of an additional grid
leak 88 forming part of a modulator Se for im
is shown the blanking key S1 including a disk 8|
pressing on the carrier an additional frequency
having an insulating sector 32 and moving. be
for distinguishing between the two halves of the
tween the brushes 33 and 34. The interrupter Si
azimuth circle. The grid leak 88 is periodically
operates to interrupt the plate voltage supplied 10 short-circuit.-d by the interrupted disk 41 having
t
For reasons of simplicity, the heating devices
08 and d0. The disk which is driven by the
for the cathode, such as for example the filament
motor shaft I8 cooperates with brushes 50 and
battery, are not shown in the wiring diagrams.
8| connected to the grid leak 88 through a relay
Referring now to the receiver, the antenna coil 15 08. The relay may be of conventional ther
10 of the doublet antenna l I is coupled to the
mionic type and includes a make-contact 89 for
oscillator circuit of the receiver by means of a
rendering the modulator S'a operative. The
grid inductance 'I9 in the oscillator circuit; The
make-contact is operated 'through the output of
constants of the detector circuit of the receiver,
tube 90 controlled by the inductance
more particularly the magnitude of the grid leak 20 a,¿lethermionic
which forms part of the device shown in Fig.
00, are so chosen that its self-oscillations are
8 for modulating the signals in response to
periodically interrupted in a manner causing
azimuthal
direction.
super-regenerative action at a frequency above
Preferably, the grid resistor 88 is made small
the range employed at the transmitter, this being.
as compared to resistors 'I5 and 16 in order to
in the illustrated form, frequencies of more than 25 maintain the carrier output substantially con
3,000 cycles. The detector circuit includes a
stant regardless of whether the modulator S3 is
thermionic tube 8i having a plate inductance 82
in operation or not. So proportioned, a dis->
connected thereto, the other terminal of the plate
tance indicator operating on 4the volume meter
inductance |being connected to the plate induct
ance 'I9 through a blocking condenser 88. The 30 principle will remain practically unaffected by
the modulator S3.
'
plate circuit is completed’ through an amplifying
The relay @i0 further includes the' usual grid
transformer 80 and the plate battery 85.' ‘l
bias battery 8i and plate battery S2. The relay
The resonant frequency of the detector circuit
is actuated in response to the movement of the
is controlled by two tuning elements. the primary
tuning being effected by a tuning element oper 35 mass 36 with respect to the inductance 45 for
directions within one-half of the azimuth circle.
ated in response to altitude.
For directions within one-half of the azimuth
In the illustrated embodiment, there is shown
circle the make-contact 89 will be closed, there
a condenser lé! operatively connected to an
by rendering the modulator S3 operative. For
evacuated diaphragm I6 in a manner illustrated
directions within the other half of the azimuth
in Fig. 5. A secondary tuning element shown as
circle, the make-contact 89 will be open and the
a condenser i5 is mechanically operated from
outgoing signals will not be modulated by the
a shaft 'it to permit periodic scanning of a band
modulator Se.
`
of carrier frequencies in the manner herein
before described.
The condenser I5 is preferably of the 270°
type as shown in Fig. 6. The condenser has
stator and rotor elements 88 and 8l so shaped
that a rotation of the shaft 24 will cause a
gradual increase or decrease in capacity during
a rotary movement of 270°. After reaching
the position of maximum or minimum capacity,
the condenser is restored to its position of min
imum or maximum capacity, respectively, by
further rotation of 90° in the same direction.
The condenser I5 operates periodically to de
crease the resonant frequency of the detector` so
as to effect scanning of a, frequency band of
A variable modulation frequency is impressed
on the signal in response to azimuthal direction.
The azimuth modulator M2 operates preferably
within the range of five to seven hundred cycles
and includes the inductance 35 hereinbefore
described in connection with Fig. 8 having a. tap
intermediate its terminals.
>
The azimuth-responsive modulator M con
stitutes an oscillator of the “Hartley" type, well
known in` the art, and includes a thermionic
tube 83, a grid leak 8l and condensers 95, 9S
and 91.
`
The output of the azimuth responsive modu
lator‘may be amplified by an amplifier includ
ing a thermionic `tube 98. The amplifier is
shown to'be of conventional form and includes
a frequency associated with plus/minus 1,000
feet of altitude dißerence with respect to the 60 further a volume control 99, a bias resistance |00
and a' coupling condenser IOI. AA coupling
altitude of the airplane on which the receiver is
transformer |02 is provided to modulate the- '
used. Referring to the chart 2b, the width of
` transmitter.
'
the band is .2 megacycle.
Referring now to the receiver, the detector
'The detector circuit operates through an
amplifier A of conventional structure. an indi 65 -and amplifier circuits as well as the altitude in,
dicator are not shown in detail in this flgure.
cator of the form hereinhefore described. Pref
The direction indicator 52 may be connected to
erably there is interposed between 'the receiver
the receiver through band-pass filters F2 and`
and the indicator a band-pass filter F1 of con?
Fa which are of conventional construction and
ventional structure permitting only signals toV
pass through which have the characteristic 70 will, for this reason,not` be further described.
The band-pass ñlter` F2 is tuned to permit
modulation impressed by the transmitter, in the
only
the frequencies to pass therethrough which
illustrated form of the invention this being a
are
modulated in response to changes in
modulation frequency of 100 cycles. 'I'he ele
azimuthal direction, in the illustrated embodi
ments of the band-pass ñlter are conventional
and will, for this reason, not be further described. 75 :ment frequencies between 500 and '100 cycles.
predetermined width. A suitable band includes
3,403,603
'
13
.
The filter F: is so tuned as to permit only dis
tinguishing frequencies to pass through, in the
illustrated form of the invention frequencies of
about 3,000 cycles for actuating the selector relay
5_9.
5
The selector relay includes a movable arma
craft which includes transmitting wireless signalsof a carrier frequency lwithin the limits of a pre
determined band; varying said frequency within
said band in dependence on the altitude of the
transmitting craft; modulating said carrier fre
.quency by a modulating frequency; and ,varying
said modulating frequency in dependence on the
ture |03 cooperating with a pair of contacts |04
and |05 for supplying current to lamps 51 and 50
azimuthal direction of flight of said transmitting
'respectively from a battery |00.
The lamps 51 and 58 illuminate opposite halves 10
2. The method of communication between air
of the directional dial 55, a member |01 being
craft which includes transmitting wireless signalsprovided to prevent light from one bulb from
.of a carrier frequency within the limits of a pre
illuminating the other half of l»the dial.
determined band; varying said frequency within
’I‘wo pointers 53 and 54 are movable relatively
said band in' dependence on the altitude of the
to the dial to indicate direction. 'I'he pointers 15 transmitting craft; modulating said carrier fre
craft.
53 and 54 are connected to an actuating member
to move in opposite directions.
`
»
`
'
quency _by a first modulating frequency; varying
said first modulating frequency in dependence on '
In the illustrated embodiment there is shown a
movable element |08 having a shaft |09. A gear
the azimuthal direction of flight of the trans
mitting craft over yboth halves of the azimuth
|I0 on the shaft |00 meshes with the pinion |||- 20 circle; and modulating said carrier frequency by
on the shaft of the pointer 54. A second pinion
a second modulating frequency during o_ne half
||2 on the shaft of the pointer 53 meshes with
of the azimuth circle.
pinion ||| to move the pointer 53 in the opposite
3. In a communication system for aircraft;
`direction. The gear train ||0,_ | || is employed in
means responsive to the altitude of the craft; a
order to amplify the limited movement of the ele
radio transmitter controlled by said altitude rement |00 to a movement of approximately 180°
sponsive means for transmitting signals of acar
for actuating the pointers in order to obtain a dial
rier frequency proportional to the altitude ~of thesimilar to a compass dial. The movable element
craft, said transmitter including means for modu
|08 moves relatively to two field coils | I3 and ||4
lating the transmitter output; -and means re
respectively.
30 sponsive to the azimuthal direction- of flight of
One terminal of the ñeld coil H4 is connected
the craft for adjusting said modulating means
through a resistance | I5 to oneI output terminal of
the band-pass ñlter. The corresponding terminal
of the other field coil ||3 is connected to the
for varying modulating frequencies in dependence
on -the azimuthal direction.
,
4. In a communication system Afor aircraft;
other output terminal of the band-pass illter> 35 means responsive to the altitude of the craft;
through an inductance H6.
_
The two remaining terminals of the field coils
are connected to a point between an inductance
means responsive to thev azimuthal direction o_f
. the craft; a radio transmitter controlled by said
altitude responsive means for transmitting sig- . i
H1 and a resistance ||8 leading to terminals
nals of a carrier frequency proportional to the
of the resistance ||5 and the inductance H5. 40 altitude of the craft, said transmitter including
respectively.
first means controlled by said direction respon~
An incoming signal, if modulated by a 3.000
sive means for modulating the transmitter signals
cycle frequency, will cause one-half of the direc
by a modulating frequency increasing for one half
tional dial to be illuminated. If the'signal is not
of the azimuth circle and decreasing for the other
so modulated, the other half of the dial will be
half of the azimuth circle, and second means
illuminated. The movable element |08 will as
controlled by said direction responsive means for
sume a position relatively to the fleld coils | I3 and
||4 in dependence on the variable modulating
additionally modulating the transmitter signals
during only one half of the azimuth circle, where
frequency representing azimuthal direction which
_by altitude and direction of the craft' are distinctly .
is thus indicated to inform the pilot of the course 50 communicated.
y
of other craft in the vicinity.
5. In a communication system -for aircraft the
In many applications of the present invention,
4combination with a directionally, and altitude
it is advantageous to restrict the operating range
controlled transmitter for transmitting signals of
of the transmitter and the receiver in order to
variable carrier frequency in dependence on alti
limit the response of the receiver to transmitters
tude, and of variable modulation frequency in de
within less than a. predetermined distance. This
pendence on azimuthal direction of a craft; of
may conveniently be done by limiting the output
signal receiving means comprising, in combina
of the transmitter, or the sensitivity of the re
tion, periodically operated power means; a radio
ceiver, or both, to avoid a response to signals of
receiver including means operated by said power
transmitters beyond the predetermined range.
eo means for periodically tuning said receiver to suc
In aerial navigation, for example, it is essential
eessive frequencies, altitude indicating means
only that a pilot be advised of flight data of other
jointly operated by said power means and the out
planes in his vicinity, while information about
put of said receiver; a frequency responsive actu
the altitude of remote planes is relatively unim
ating element responsiveto the modulation fre
portant since the danger -of collision in mid-air
_quency of signals received by said receiver; and
does not exist in the latter case.
directional indicating means operable by said ac
Obviously, the present invention is not re-.
tuating element.
‘
stricted to the particular embodiments herein
6.v In a communication system for aircraft the
shown and described. Moreover, it is not indis
combination with a 'directionaily and altitude
pensable that all the features of this invention be 70 controlled transmitter for transmitting signals of
used conjointly as they may advantageously be
'variable carrier frequency in dependence on al
employed in various combinations and sub-com
titude,l and of variable modulation frequency in
binations.
'
dependence on azimuthal direction of a craft; of
What is claimed is:
signal receiving means comprising, in combina
1. ’I'he method of communication between air
tion, periodically operated power means; an a1
2,403,603
of a signal is indicated by the instantaneous ro
timeter; a radio receiver including primary and
tary position of said rotatable element, the rotary
secondary tuning means, said primary tuning
position representing altitude difference of a
means being connected to be operated by said al
transmitting
craft with respect to the receiving
titude responsive means for tuning the receiver
to a carrier frequency proportional to the altitude
9. A communicationdevice for aircraft as set
of the receiving craft, said secondary _tuning
forth in claim 8 in which there is additionally
means being connected to be operated by said
provided a modulating device driven by said mo
power means for tuning said receiver during each
tor and controlling said transmitter for interrupt
cycle of operation to successive carrier frequencies
within a frequency band of predetermined width 10 ing the transmitter output at a predetermined
frequency; and a qfilter tuned to- the frequency of
the frequencies of the band depending on the
said modulating device, said filter being inter
primary tuning; altitude indicating means jointly
posed between said receiver and said indicating
operated by said power means and the output
craft.
‘
'
'
means for blocking from said indicating means
of said receiver; a frequency responsive actuating
element responsive to the modulation frequency 15 signals of other than said predetermined fre
quency, thereby preventing erroneous actuation
of signals received by said receiver; and direc
of said indicating means by stray signals.
tional indicating means operable by said actuat
10. A. communication device for aircraft com
ing element.
prising, in combination, a iirst craft provided
'7. In a communication system for aircraft the
combination with a directionally and altitude con 20 with an azimuth _direction indicator; a first mo
tor adapted to run `at substantially constant
trolled transmitter for transmitting signals of
speed; a radio transmitter including a variable
variable carrier frequency in dependence on al»
tuning device; means responsive to the altitude
titude, and of multiple modulation including mod
of the craft for tuning the transmitter to a‘car
ulation by a variable frequency in dependence
on an azimuthal direction of a craft and“ addi 25 rier frequency proportional to the altitude of the
craft, a ñrst modulator operable by said direc
tional modulation by a fixed frequency for direc
tion indicator for modulating the transmitter sig- tions within one half of the azimuth circle; of
nais in dependence on the direction of the craft,
signal receiving means comprising, in combina
and a second modulator operated by said direc
tion, periodically operated power means; an al
timeter; a radio receiver including primary and 30 tion indicator for additionally modulating said
signals by a predetermined fixed frequency dur
'secondary tuning means, said primary tuning
means being connected to be operated by said a1
titude responsive means for tuning the receiver
to a carrier frequency proportional to the altitude
ing flight directions within one half of the azi
muth circle; a switch operated by said motor for
periodically rendering said transmitter inoper
of the receiving craft, said secondary tuning 35 ative; a second craft provided with a receiver in
cluding a first and a second tuning element;
means being connected to be operated by said
means responsive to the altitude of the craft for
power means for tuning said receiver during each
adjusting said first element to tune said receiver
cycle of operation to successive carrier frequencies
to a carrier frequency proportional to the alti
within a frequency band of predetermined width
the frequencies of the band depending on the pri 40 tude of the craft, a second constant speed motor
for periodically tuning said receiver to succes
mary tuning; altitude indicating means jointly
sive carrier frequencies within. a predetermined
operated by said power means and the output of
band, thereby scanning said band for signals, the
said receiver; a frequency responsive actuating
location of the band being determined by said
element responsive to the variable modulation fre
first receiver tuning; an amplifier connected to
quency of signals received by said receiver; means
said receiver for amplifying its output; altitude
responsive to said ñxed frequency; and directional
indicating means including a rotatable element
indicating means jointly operable by said actu
driven. by said second motor, and a fixed element
ating element and said fixed frequency responsive
cooperating with said rotatable element, one of
means.
8. A communication device for aircraft com 50 said elements being a glow lamp operated by
said amplifier whereby altitude of the second
prising, in combination, a motor adapted to run
craft relatively to the first craft is indicated by
at substantially constant speed; a radio trans
mitter including a variable tuning device; means ' the rotary position of said elements at the in
stant of lightingof said lamp; directional indi
responsive to the altitude oi' the craft connected
to said tuningdevice for tuning the transmitter 55 cating Ameans including a frequency responsive
first actuating element connected >to respond to
to a carrier frequency in dependence on the a1
the variable modulation frequency of incoming
titude of the craft; a switch operated by said mo
tor for periodically Írendering said transmitter
inoperative; a receiver including a first and a sec
signals,` a frequency responsive second actuat
ing element connected only to respond to signals
ond tuning element; means responsive to the al 60 modulated by said firstyfrequency, thereby dis
tinguishing .between directions within the two
titude of the craft for adjusting said first element
to tune said receiver to a carrier frequency pro
portional to the altitude of the craft, said second
element being driven by said motor for periodically
tuning said receiver to successive carrier fre
quencies within a predetermined band, thereby
scanning said band for signals, the location of the
band being determined by said first tuning ele
ment controlled in response to altitude; an am
pliiier connected to said receiver for amplifying
its output; and indicating means including a ro
tatable element driven by said motor, and a fixed
element cooperating with said rotatable element,
one of said elements being a glow lamp operated
by said amplifier, whereby the instance of receipt
halves of ’the azimuth- circle, ' and indicating
means operated by said actuating elements.
11. A communication apparatus for aircraft
comprising, in combination: a transmitter of
wireless signals; a device responsive to the alti
tude of said apparatus for tuning said transmit
terv to a carrier frequency proportional to the
altitude of said apparatus, and means for modu
latins said signals by a predetermined frequency
'to distinguish said signals over lstray signals; a
receiver of wireless signals including filter means
for excluding signals of other than said prede
termined modulation frequency, whereby inter
ference by stray signals is prevented; a device
17
responsive to the altitude of said apparatus l-for
tuning said receiver to a carrier frequency pro
portional to the altitude of said apparatus;
power operated means for varying the tuning'of
18A
of tuning of said receiver to the transmitterV
frequency.
said receiver through a band of carrier fre
14. A communicationl apparatus for aircraft
comprising, in combination, a transmitter of wire
less signals including a tuning element for tuning
quencies bearing a predetermined relation with
the tuning effected by said altitude responsive
device; an altitude indicator jointly operated by
said transmitter to transmit signals within a pre
determined band of carrier frequencies, and an
oscillator for modulating said signals by a pre
said power operated means and by the output
determined modulation frequency; an altitude
of said receiver; and means operated by said 10 responsive device for operating said tuning ele
power operated means for rendering said trans
ment to tune said transmitter to a carrier fre
mitter inoperative during the period of tuning
quencyproportional to the altitude ofthe craft:
of said receiver to the transmitter frequency.
a receiver of wireless signals, said receiverin
12. A communication apparatus for aircraft
cluding means for tuning said receiver to a car
comprising, in combination, a transmitter of 15 rier frequency of incoming signals; altitude re
wireless signals, said transmitter comprising a
sponsive means for operating said tuning means
first tuning element for varying the carrier fre
to tune said receiver to a carrier frequency pro
quency oi' said signals within a predetermined
portional vto the ,altitude of lthe craft; power .
band of carrier frequencies, and a modulating
operated means for varying the tuning-of the
oscillator including a second tuning element .for 20 receiver cyclically through a band of carrier fre
varying the modulation frequency of said signals
quencies bearing a predetermined relation to
within a predetermined band of modulation fre
the tuning effected by said altitude responsive
quencies; a device responsive to the altitude of
means; indicating means jointly operated by said
the craft for operating one of said tuning ele
power operated means and by the output ofsaid
ments in dependence on the altitude of the craft; 25 receiver; filter means for excluding from said
a device responsive to the azimuthal direction
indicating means signals of a modulation fre
of the craft for controlling the other of said
quency other than that of said oscillator; and
tuning elements in dependence on the direction
means operated by said power operated means
of the craft; a receiver of wireless signals Ain
for rendering said transmitter inoperative dur
cluding first power operated variable tuning 30 ing the period of tuning of said receiver to the
means for tuning said receiver to incoming sig
carrier frequency of the transmitter.
nals of carrier frequencies within said prede
l5. A communication apparatus for aircraft
termined band, and second means for determin
comprising, in combination, a' transmitter of wire- »
ing the modulation frequency of incoming sig
less signals, said transmitter including a tuning '
nals; an'altitude indicator; an indicator of azi
muthal directions, one of said indicators being
jointly operated by 'the output of said receiver
and said ñrst tuning means, the other indicator
signals within a predetermined band of carrier
frequencies, and an oscillator for modulating said
being operated by said second means; and means
element for tuning said transmitter to transmit
signals, the oscillator including a variable tuning
device; means responsive to the altitude of the
coupled with said first tuning means for render 40 craft for actuating said tuning element in de
ing said transmitter inoperative during the pe
pendence on`the altitude of the craft, whereby the
riod of tuning of said receiver to the transmitter
carrier frequency of the signals _becomes a meas
frequency.
13. A communication apparatus for aircraft
ure of the altitude of the craft; and means re
sponsive to the azimuthal direction of the craft
comprising, in combination, a transmitter of ' 45 for actuating said tuning device in dependence
wireless signals, said transmitter comprising a
ñrst tuning element for varying the carrier
frequency of said signals within a predetermined
:band of carrier frequencies, and a modulating os
cillator including a second tuning element for
varying the modulation frequency of said signals
within a predetermined band of modulation fre
quencies; a device responsive to the altitude of
the craft for operating said ñrst tuning element;
a device responsive to azimuthal direction of
the craft for controlling said second tuning'
element; a receiver of wireless signals including
tuning means for tuning said receiver to a fre
quency of incoming signals of carrier frequencies
within said predetermined band; means respon-_
sive to the altitude of the craft for operating
said tuning means to tune said receiver to a
frequency proportional to the altitude of the
craft; power operated means for varying the
tuning of the receiver cyclically through a band
of carrier frequencies bearing a predetermined
relation to the tuning effected by said altitude
responsive means; an altitude indicator jointly
operated by the output of said receiver and
on the direction of iiight of the craft, whereby
the modulation frequency becomes a measure of
the azimuthal direction of the craft.
16. A communication apparatus for aircraft
50 comprising, in combination, a transmitter of wire- n
less signals, said transmitter including a tuning
element controlling the carrier frequency of
transmitted signals, a first' oscillator for modu-l
lating said signals, said ñrst oscillator includ
55 ing a variable tuning device, and a second oscil
lator tuned to a predetermined spot frequency;
means responsive to the altitude of the craft
for actuating said tuning element in dependence
on the altitude of the craft, whereby the c_arrier
60 frequency of the signals becomes a measure of the
altitude of the craft; means responsive to the
azimuthal direction of thecraft for actuating
said tuning device in dependence on the direc
tion of flight of the craft, whereby the modula
65 tion frequency becomes a measure of the azi
muthal direction of the craft; and means respon
sive to the azimuthal direction of the craft for
rendering said'second oscillator operative for di
rections within one half of the azimuth circle
said power operated means; means responsive to 70 and inoperative during the other half.,
the modulation frequency of an incoming signal;
a direction indicator operated by said modulation
frequency responsive means; and means coupled
with said power operated means for rendering
17. The method of communication between air
craft which comprises transmitting from a first
craft a carrier wave, varying the frequency of
said carrier wave according to the altitude of
said transmitter inoperative during the period 75 said first craft, modulating said carrier wave by
u
..
u
..
„.
,
19
20
quencies, altitude indicating means including a
rotatable element coupled to said rotatable
a first modulating wave, varying the frequency
of said first modulating wave according to the
member and an element cooperating with saidv
azimuthal direction of the nrst craft over both
rotatable element to provide an indication, one
halves of the azimuth circle, modulating said
of said elements being actuated in response to
carrier wave by a second _modulating wave dur
the receiver output whereby the altitude of said
ing only one-half of the azimuth circle, there
transmitting craft is determinable from the
by communicating the altitude and direction of
relative position of the two elements at the in
said first craft; receiving said communication
stant of reception, direction indicating means
on a second craft, said receiving comprising theincluding a ñrst modulation wave responsive
steps of cyclically scanning said carrier wave 10 means operated by the output of said receiver in
throughs. band of predetermined width, varying
dependence upon the ñrst transmitted modulated
the location of said scanned band according to
wave to give over both halves of the azimuth
the altitude of the second craft to derive an indi
circle an indication corresponding to the direc
cationof altitude of said nrst craft, and deriv
tion of night of said transmitting craft, and
ing anadditionalsignal from said first and sec
second modulating wave responsive means
ond modulations to determine the direction of
said first craft.
’
responsive to said second transmitted modulating
wave for visually. distinguishing between the
i8. In va communication system of the char
opposite halves of the azimuth circle. l
acter` described including a transmitting craft
20. In a communication system for aircraft,
20
having a transmitter sending a carrier wave
a first craft having a transmitter comprising
whose frequency var-ies with the altitude of the
means for transmitting a wave whose frequency
transmitting craft, said carrier being modulated
has a value dependent upon the magnetic
by a first modulating wave; a receiving craft
heading of the transmitting craft, the value of
comprising periodically operated power means
said frequency varying between maximum and
25
including a rotatable member, a radio receiver
minimum as the craft’s heading changes from
including means operated by said power means
opposite points of the azimuth circle, said
for periodically tuning said receiver to successive
transmitter having means for transmitting a
frequencies on a band of carrier frequencies,
Wave of .a second and fixed frequency for
altitude indicating means including a rotatable
headings corresponding to one-half of the
30
element coupled to said rotatable member and
azimuth circle between said opposite points: a
an element cooperating with said rotatable
second craft having a receiver comprising means
element to provide an indication, one of said
for deriving
said
first wave
for indicating
elementsv being connected to be actuated in
headings between said opposite points, and means
response to the receiver output whereby the alti
for deriving said second frequency for determin
35
tude of said transmitting craft is determinable
ing in which half of the azimuth circle said first
from the relative position of the two elements
means shall indicate.
at the instant of reception, indicating means
21. In a communication system for aircraft, a
including modulation wave responsive means
ñrst craft having a transmitter comprising
operated by the output of said receiver in de
means for transmitting a carrier Wave, means
pendence upon the transmitted modulated wave 40 for modulating said carrier wave with a modu
of the transmitting craft.
lating frequency having a value dependent upon
19. In a communication system of the char
the magnetic heading of the transmitting craft,
acter described including a transmitting craft
the value of said modulating frequency varying
having a transmitter sending a carrier wave
whose frequency varies in proportion to the
altitude of the transmitting craft. said carrier
being modulated by a ñrst modulating wave
between maximum and minimum vas the craft’s
heading changes from true north to true south;
said transmitter having means for modulating
said carrier wave with a second and fixed modu
whose frequency varies with the direction of
lation frequency for headings corresponding to`
night of the transmitting craft, said carrier Wave
one-half of the azimuth circle between north and
being modulated by a second modulating wave 50 south; a second craft having a receiver compris
for ñlght directions within one half of the
ing means for derivingsaid first modulating wave
azimuth circle; the combination with a receiving
for indicating headings between north and south,
craft comprising periodically operated power
means including a rotatable member, a radio
receiver including means operated by said power
means for periodically tuning said receiver to
successive frequencies of a band of carrier fre
and means for deriving said second modulating
A55 wave for determining on which half y, of the azi-
muth circle said ñrst means shall indicate.
ARTHUR KORN.
Документ
Категория
Без категории
Просмотров
0
Размер файла
1 972 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа