[Milsurplus] Mil FM

[Bob Camp]

Hi

The Ham world started to go over to VHF FM when the commercial gear 
went from wide spaced channels to narrow spaced channels. This created 
a whole bunch of obsolete gear in the major metro areas. It was all 
tube based, but it got the process going at a fairly low level. The 
real push came when solid state gear began to displace the tube based 
commercial FM gear. The FM thing was driven by surplus, just not 
military surplus.

I think the main issue was that in the 1940's there just was not much 
amateur experience with the FM radios.  They were hard to pickup with a 
super regen and didn't talk to the existing VHF nets. When things 
picked up in the mid to late 1960's you could still find radios that 
had been in mothballs since the early 1950's.

The big driver was setting up repeaters. Without a local repeater there 
wasn't much VHF FM at all. Once a repeater went up things began to 
move. Commercial repeaters (and cavities) were a lot easier to get than 
their military counterparts. At least that was true for the 600 KC 
spacing  that fit on the 2 M ham band.

	Take Care

		Bob Camp
		KB8TQ


On Apr 24, 2005, at 2:07 AM, Hue Miller wrote:

> Referring to the manual to try to figure out the harness, then hefting 
> the
> thing on my back, i was thinking-
>  the thing with full battery load looks like a real load for the 
> canvas, especially
> if you're running a jostling it a lot. I wonder if the canvas tended 
> to give out?
> I've seen TBY canvas that the straps stitching has tended to come 
> apart, for
> the same reason
> the thing is not as difficult to battery up as i'd thot. 4.5, 90, 150 
> volts- not
> as bad as the TBY or worse, the BC-222/ 322.
> you could get away, i wager, with just running the +150 off the +90 
> line
> instead, if the +90 source was stiff. Final power would be down, but 
> you're
> not operating under Combat Emergency conditions. The transmitter mixer
> would be the question mark.
> it looks easy to substitute plug-in solidstate replacements for some 
> tube
> functions, like the final, or a diode tube, for example. Note,  i said 
> "plug-in",
> as in, built on tube bases, tube plugs. Maybe even all functions.
> military VHF FM gear never became very popular during the golden
> years of surplus, did it? I mean, hams hacked with alacrity on the VHF 
> AM
> gear, the ARC-4's, the ARC-1's, the UHF APN's and BC-645s. But hams
> didn't seem to go for FM mode back then. Even the push button tank sets
> didn't really get much action on 10, converted Command Sets seem to 
> have
> been more popular there too.
> -Hue Miller
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