[ARC5] [Milsurplus] Radio on the Frontlines: WWI and WWII | DPLA

[Hubert Miller]

Their standard VHF aircraft radio, Fu.G.16, tuned 44 - 50 MHz with 4 mechanical presets. 
I do not think vacuum tube technology permits higher frequency communications equipment with 
free-running LC oscillators. The U.S. I understand had some VHF variable - frequency sets to expand
the "Command Sets" series to VHF, but I don't think that worked out well. In any case these sets are
rarely seen while the standard VHF sets were all quartz stabilized. 
I won't be the first to state that some German war equipment was overbuilt for its expected longevity.
Like the Tiger tank, very expensive to build, and low production numbers.
-Hue 

-----Original Message-----
From: arc5-bounces at mailman.qth.net <arc5-bounces at mailman.qth.net> On Behalf Of Tom Lee
Sent: Monday, March 9, 2020 4:27 PM
To: arc5 at mailman.qth.net
Subject: Re: [ARC5] [Milsurplus] Radio on the Frontlines: WWI and WWII | DPLA

I visited the Deutsches Museum in Munich a year or so ago (one of my favorite museums on the planet), and had a chance to speak with one of the docents who manned their amateur radio display. He claimed that their quartz-free WWII radios were stable to about 0.1% over temperatures encountered in the field (whatever that means). He could not cite any source for this claim, but offered plausible explanations. 
He said that the main bit of magic was pre-stressed inductor windings on low-TC coil forms (the coils were wound with heated wires which contracted upon cooling, so that the overall inductor TC was that of the form, not of the wire). Not as good as quartz, he admitted, but it mainly got the job done. I've heard of this pre-stressing method before, but this gentleman seemed to imply that it was a German innovation. I have no idea if that is in fact the case.

--Tom

--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
http://www-smirc.stanford.edu