[Milsurplus] tank radio skip?

[Hue Miller]

----- Original Message ----- 
From: "Bob Camp" <ham at cq.nu>
Subject: Re: [Milsurplus] tank radio skip?



> 1) There is repeated reference to the German efforts at intercept in 
> North Africa. ...There > are both German and British sources to back this up.
 It'll take me a  while to dig them up but I probably can.

I have somewhere a book on this subject alone, from the Afrika Korps perspective,
in German...dunno where it went during my recent move....I'll give the title (again)
when i recover it....

> 3) One version of the story has a connection between the Connecticut 
> State Police VHF radio experiments tying into the intercept plan. 
> Another version has a couple of hams picking up the signals. 

I'd suggest the SWL scenario more likely. I suspect at this date the Police Dept.
experiments were with FM, since low-vhf police radio was already well 
established. Plus crystal-controlled receivers. The tank equipment was all
vfo'd, and no doubt frequencies frequently changed.
 
> 4) Like it or not propagation is affected by sun spots. If you check 
> out the period in question it was not anything like a sunspot maximum. 
> That does not say that the contacts were impossible, only that they 
> were a lot less likely.

Nevertheless, there have been a good number of vhf dx contacts during 1939-1942.
Like in 1940, coast-to-coast on a walkie talkie ( SCR-194 ).

> 5) Unlike our new friends the Germans didn't seem to think that a 
> couple of KW of RF was needed for tank to tank communications. What 
> ever they were doing, it was with low power sets.

Actually, in terms of radiated power, the output of the German vhf tank sets
and the English HF equipment, the German radios probably radiated more,
for dx work, but for close in, i suspect the greater ground wave of the English
HF equipment reached out more. The German radios were rated at about 5, 10,
and 20 watts output depending on set. The 19 set, i dunno exactly, maybe input
15 watts, then thru a highly inefficient bottom loaded whip, with a shielded 
load coil!,  operating somewhere between 80 and 40 meters, approximately. 
( An additional feature of the UK tank equipment: you could listen to the BBC
and whatever else, after working hours. )

I recall reading, i think it was in Short Wave Magazine ( U.K. ) that in an early
battle, this before the US entered the war, U.K. tanks received QRM from US
stateside hams! -Hue Miller