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From: Reginald Curtis <reginal..._at_hotmail.com>
To: <tscm-..._at_googlegroups.com>
Subject: RE: [TSCM-L] {2793} Re: Receiver oscillator as transmitter
Date: Thu, 26 Feb 2009 19:59:40 +0000
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Humberto,
=20
Sorry for the belated reply to your posting. Other matters active at the ti=
me and I just let that day's emails slip after that. Anyway, two points rel=
ating to radio receiver uninteded transmissions by ships using 1930's (and =
perhaps earlier) technology during WW II.
=20
1. Apparently, many if not all, were using the earlier regerative technolog=
y as opposed to a superhetrodyne circuit.=20
=20
2. Probably not a major item but interesting. At the beginning of the war m=
any ships were wired for 110 volts DC as opposed to the usual 110 AC. I am =
not sure how long this continued to be the norm.
=20
Thanks again,
Reg Curtis/VE9RWC
=20
Date: Wed, 6 Aug 2008 15:32:33 -0300
From: hrs..._at_gmail.com
To: TSCM-..._at_googlegroups.com
Subject: [TSCM-L] {2793} Re: Receiver oscillator as transmitter
=20
Red,=20
Forgive me for my mistakes, because I=B4m not fluent in English.
Here in Brazil in my Engineering of Communications Course, I had Dr. Theodo=
r Helmut Schreyer as a teacher. He was a German engineer who took a PhD in =
Berlin in the year 1939. In his doctoral thesis he submitted a new circuit,=
which was a flip-flop mounted with the gas valves, since there was not the=
technology of semiconductors only discovered in the 50's. He confirmed tha=
t at the beginning of the World War II the receivers of German submarines h=
ad not buffers and the RF signal from antenna followed directly to the mixe=
r where it was mixed with the local oscillator signal resulting FI. This ca=
uses that only with the receivers ON, the RF signal produced by local oscil=
lator was radiated by the antenna, which allow British Navy to locate the s=
ignal from the local oscillator of radio receivers, and destroy the German =
submarines.=20
Dr. Schreyer was instructed by German Navy to develop a solution and he cre=
ated a intermediary stage (buffer) between antenna and mixer, which was an =
amplifier that receives the signal from the antenna, amplifies and delivery=
to the mixer, thrn mixed to the signal from the local oscillator, resultin=
g in FI, which is processed and demodulated in the following stages, as is =
currently the case with any superheterodine receiver.=20
After the end of World War II, Dr. Schreyer, unlike many other scientists w=
ho went to the United States or to Russia, came to Brazil where he lived un=
til the end of his life as head of Brazilian Postal Services Laboratory and=
as a professor in the Military Telecommunications Engineering Institute, =
a Brazilian Army school where I was graduated as communications engineer in=
1979. He was one of the best and most capable teachers I had.
Regards,
Humberto Rigotti
2008/8/6 <reginal..._at_hotmail.com>
In World War II, there was some fear that German submarines were
locating Allied ships by 'dfing' oscillations from ships' receivers.
The following comes from the July 2008 issue of 'Practical Wireless',
a British magazine dealing with Amateur Radio. The article, at pages
44-46, is titled "Amateur Radio Personality" and gives a career
profile of G3IK who started out as a junior radio operator in the
merchant marine in 1943. He later became an electronics engineer. One
very interesting portion deals with his experiences as an operator
during the war and relates to the use of a ship's receiver as a
transmitter. The article commences with:
" Rob G3XFD: 'Thank you for agreeing to be featured as our Amateur
Radio Personality Ed! You've had a remarkable life and the letters
following your name, including MBE, surely reflect your adventures?
When did you first get interested in radio?'
Ed Chicken G3BIK: 'It's my pleasure to join you Rob, I'm delighted to
share my story to you for PW readers. My lifelong involvement with
radio began at 15 years old in 1943 using Morse code on and about
500kHz at the Colwyn Bay Wireless College, North Wales where I
obtained a PMG Certificate in Wireless Telegraphy.
Maritime receivers were still mainly t.r.f. [tuned radio frequency?]
types with reaction, but because the transmitters all used tone-
modulated carrier (m.c.w.), the receiver's reaction control was used
primarily to maximise the receiver's sensitivity, just on the verge
of, but not quite "plopping" into oscillation, such as would have been
necessary for reception of c.w.'
Rob G3XFD: 'Life in the Merchant Navy was incredibly dangerous in the
Second World War Ed!'
Ed G3BIK: 'Yes, it was risky as we crossed the Atlantic in slow
merchant ships. However, we were warned to avoid turning the
receiver's reaction [r.f. gain?] up too far whilst at sea, as it could
act as a transmitter on 500kHz enabling enemy U-boats to locate us!'
.....
Rob G3XFD: 'A narrow escape Ed, but I think that you have had some
more adventures and managed to use your Spanish again very soon
afterwards?'
Ed G3BIK: 'Yes Rob, engine failure gave me my first opportunity to
break the mandatory radio silence on 500kHZ, to seek help via the
Americans in Panama. The IFF unit was used in earnest when an American
Catalina flying boat came to meet us. ....'
.......
Rob G3XFD: ' You obviously had an eventful war Ed! What direction did
your career take you in peacetime?'
Ed G3 BIK: 'Having left the Merchant Navy, I got a shore job mending
domestic wireless sets, a service in demand because new sets weren't
available. I applied for and was granted my own Amateur licence with
callsign G3BIK. My PMG certificate exempted me from exams but I was
still restricted to 10 watts of c.w. for the first year.
War surplus equipment became readily available at attractive prices
but I couldn't take real advantage of that because my parent's home
didn't have electricity! So, I acquired a battery-operated trawler-
band two valved [two-tubed] t.r.f. receiver with "reaction", I used
the house wireless-aerial and earth spike and began searching for
Amateur transmissions on the 160 metre top-band. To my great delight I
heard G6UP calling "CQ" in Morse, but only recognisable as c.w. tones
after turning up the "reaction".
My excitement was boundless, as was the frustration of not yet having
a transmitter to reply. That's when the wartime warning about the rash
use of 'reaction' sprang to mind, so I unplugged the h.t. wander-plug
and used it as a make-shift Morse key to tap out a response to G6UP in
hope that this would be my first ever G3BIK transmission.
Joy upon joy, he came back with "G3BIK de G6UP. UR 579c"". I was fully
readable and fairly strong but with some chirp! So the wartime concept
of receiver acting as transmitter was proven right!'
......"
The End.
Reg Curtis
_________________________________________________________________
Windows Live Messenger. Multitasking at its finest.
http://www.microsoft.com/windows/windowslive/products/messenger.aspx
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Humberto,<BR>
<BR>
Sorry for the belated reply to your posting. Other matters active at the ti=
me and I just let that day's emails slip after that. Anyway, two point=
s relating to radio receiver uninteded transmissions by ships using 1930's =
(and perhaps earlier) technology during WW II.<BR>
<BR>
1. Apparently, many if not all, were using the earlier regerative technolog=
y as opposed to a superhetrodyne circuit. <BR>
<BR>
2. Probably not a major item but interesting. At the beginning of the war m=
any ships were wired for 110 volts DC as opposed to the usual 110 AC. I am =
not sure how long this continued to be the norm.<BR>
<BR>
Thanks again,<BR><BR><BR>
<DIV>
<DIV><FONT color=3D#ff0033><STRONG>Reg Curtis/VE9RWC</STRONG></FONT></DIV><=
/DIV><BR><BR><BR>
<BR>
<HR id=3DstopSpelling>
Date: Wed, 6 Aug 2008 15:32:33 -0300<BR>From: hrs..._at_gmail.com<BR>To: TSCM-=
..._at_googlegroups.com<BR>Subject: [TSCM-L] {2793} Re: Receiver oscillator as=
transmitter<BR><BR>
<DIV dir=3Dltr>
<DIV> </DIV>
<DIV dir=3Dltr>Red, <BR><BR>Forgive me for my mistakes, because I=B4m =
not fluent in English.</DIV>
<DIV dir=3Dltr>Here in Brazil in my Engineering of Communications=
Course, I had Dr. Theodor Helmut Schreyer as a teacher. He was a Germ=
an engineer who took a PhD in Berlin in the year 1939. In his doctoral thes=
is he submitted a new circuit, which was a flip-flop mounted with the gas v=
alves, since there was not the technology of semiconductors only disco=
vered in the 50's. He confirmed that at the beginning of the World War II t=
he receivers of German submarines had not buffers and the RF=
signal from antenna followed directly to the mixer where it was mixed with=
the local oscillator signal resulting FI. This causes that only =
with the receivers ON, the RF signal produced by local oscillator was =
radiated by the antenna, which allow British Navy to locate the signal=
from the local oscillator of radio receivers, and destroy the German subma=
rines. <BR>Dr. Schreyer was instructed by German Navy to develop a solution=
and he created a intermediary stage (buffer) between antenn=
a and mixer, which was an amplifier that receives the signal from=
the antenna, amplifies and delivery to the mixer, thrn mixed to&=
nbsp;the signal from the local oscillator, resulting in FI, which is p=
rocessed and demodulated in the following stages, as is currently the case =
with any superheterodine receiver. <BR>After the end of World War II, Dr. S=
chreyer, unlike many other scientists who went to the United States or to R=
ussia, came to Brazil where he lived until the end of his life as head of&n=
bsp;Brazilian Postal Services Laboratory and as a professor in the Mil=
itary Telecommunications Engineering Institute, a Brazilian Army=
school where I was graduated as communications engineer in 1979. He w=
as one of the best and most capable teachers I had.</DIV>
<DIV>Regards,</DIV>
<DIV>Humberto Rigotti<BR><BR></DIV>
<DIV class=3DEC_gmail_quote>2008/8/6 <SPAN dir=3Dltr><<A href=3D"mailto:=
reginal..._at_hotmail.com">reginal..._at_hotmail.com</A>></SPAN><BR>
<BLOCKQUOTE class=3DEC_gmail_quote style=3D"PADDING-LEFT: 1ex; BORDER-LEFT:=
#ccc 1px solid"><BR>In World War II, there was some fear that German subma=
rines were<BR>locating Allied ships by 'dfing' oscillations from ships' rec=
eivers.<BR>The following comes from the July 2008 issue of 'Practical Wirel=
ess',<BR>a British magazine dealing with Amateur Radio. The article, at pag=
es<BR>44-46, is titled "Amateur Radio Personality" and gives a career<BR>pr=
ofile of G3IK who started out as a junior radio operator in the<BR>merchant=
marine in 1943. He later became an electronics engineer. One<BR>very inter=
esting portion deals with his experiences as an operator<BR>during the war =
and relates to the use of a ship's receiver as a<BR>transmitter. The articl=
e commences with:<BR><BR>" Rob G3XFD: 'Thank you for agreeing to be feature=
d as our Amateur<BR>Radio Personality Ed! You've had a remarkable life and =
the letters<BR>following your name, including MBE, surely reflect your adve=
ntures?<BR>When did you first get interested in radio?'<BR><BR>Ed Chicken G=
3BIK: 'It's my pleasure to join you Rob, I'm delighted to<BR>share my story=
to you for PW readers. My lifelong involvement with<BR>radio began at 15 y=
ears old in 1943 using Morse code on and about<BR>500kHz at the Colwyn Bay =
Wireless College, North Wales where I<BR>obtained a PMG Certificate in Wire=
less Telegraphy.<BR><BR>Maritime receivers were still mainly t.r.f. [tuned =
radio frequency?]<BR>types with reaction, but because the transmitters all =
used tone-<BR>modulated carrier (m.c.w.), the receiver's reaction control w=
as used<BR>primarily to maximise the receiver's sensitivity, just on the ve=
rge<BR>of, but not quite "plopping" into oscillation, such as would have be=
en<BR>necessary for reception of c.w.'<BR><BR>Rob G3XFD: 'Life in the Merch=
ant Navy was incredibly dangerous in the<BR>Second World War Ed!'<BR><BR>Ed=
G3BIK: 'Yes, it was risky as we crossed the Atlantic in slow<BR>merchant s=
hips. However, we were warned to avoid turning the<BR>receiver's reaction [=
r.f. gain?] up too far whilst at sea, as it could<BR>act as a transmitter o=
n 500kHz enabling enemy U-boats to locate us!'<BR><BR>.....<BR><BR>Rob G3XF=
D: 'A narrow escape Ed, but I think that you have had some<BR>more adventur=
es and managed to use your Spanish again very soon<BR>afterwards?'<BR=
><BR>Ed G3BIK: 'Yes Rob, engine failure gave me my first opportunity to<BR>=
break the mandatory radio silence on 500kHZ, to seek help via the<BR>Americ=
ans in Panama. The IFF unit was used in earnest when an American<BR>Catalin=
a flying boat came to meet us. ....'<BR><BR>.......<BR><BR>Rob G3XFD: ' You=
obviously had an eventful war Ed! What direction did<BR>your career take y=
ou in peacetime?'<BR><BR>Ed G3 BIK: 'Having left the Merchant Navy, I got a=
shore job mending<BR>domestic wireless sets, a service in demand because n=
ew sets weren't<BR>available. I applied for and was granted my own Amateur =
licence with<BR>callsign G3BIK. My PMG certificate exempted me from exams b=
ut I was<BR>still restricted to 10 watts of c.w. for the first year.<BR><BR=
>War surplus equipment became readily available at attractive prices<BR>but=
I couldn't take real advantage of that because my parent's home<BR>didn't =
have electricity! So, I acquired a battery-operated trawler-<BR>band two va=
lved [two-tubed] t.r.f. receiver with "reaction", I used<BR>the house wirel=
ess-aerial and earth spike and began searching for<BR>Amateur transmissions=
on the 160 metre top-band. To my great delight I<BR>heard G6UP calling "CQ=
" in Morse, but only recognisable as c.w. tones<BR>after turning up the "re=
action".<BR><BR>My excitement was boundless, as was the frustration of not =
yet having<BR>a transmitter to reply. That's when the wartime warning about=
the rash<BR>use of 'reaction' sprang to mind, so I unplugged the h.t. wand=
er-plug<BR>and used it as a make-shift Morse key to tap out a response to G=
6UP in<BR>hope that this would be my first ever G3BIK transmission.<BR><BR>=
Joy upon joy, he came back with "G3BIK de G6UP. UR 579c"". I was fully<BR>r=
eadable and fairly strong but with some chirp! So the wartime concept<BR>of=
receiver acting as transmitter was proven right!'<BR><BR>......"<BR><BR>Th=
e End.<BR><BR>Reg Curtis<BR><BR><BR><BR></BLOCKQUOTE></DIV><BR></DIV><BR></=
html>
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Received on Sat Mar 02 2024 - 00:57:17 CST