[Motorola] Antique Motorola Portables

[Geoff Fors]

The military radio crowd has created a demand for small switching supplies
to replace those high voltage batteries in sets like the PRC-6 (another
Motorola product !)  Strangely the only source for commercially made
versions is out of Italy or through one of his vendors in London.
Apparently the power supply is also capable of sensing load or lack thereof
to turn itself off without having to rewire the radio power switch.

The only problem is that in the Motorola stuff, you would need more than one
of these power supplies, but yes, those and a 6 or 12V gel cell would be the
way to go.  The 2 volt Willard cells can be replaced by Hawker lead acid 2 V
cells if you can find one that will fit.  There are some Russian wet cells
in NOS condition coming the market but they arrive dry charged and you have
to fill them with electrolyte which is somewhere between haz-mat and WMD.

The old wideband receivers seem happy with receiving modern 5 KHz deviation
signals.  However, the earliest Motorola transmitters were considerably
wider than 15 KHz and had no deviation ("IDC") control at all.  In the
cobweb-memories department, Motorola sold deviation peak limiter kits as
retrofits for the 5V and (I think) the 30D mobiles, but those still didn't
have a deviation control.  It's also interesting that because of the high
multiplication factor of the transmitter crystal on VHF high band, taxi
companies using the 30D and 5V sets were causing interference to other
services from oscillator spurs which resulted in a field mod kit and
eventually FCC attention.  It would be interesting to learn how many 30D and
5V mobiles were still in service long after their official "expiration
dates."

The military radio people are having some success using the WWII BC-683/684
tank radios on 29.6 FM since the old T-17 mikes are incapable of supplying
enough audio to overdeviate the transmitter.  However, the receiver is broad
enough that 4 channels come in all at once.

And one last, borrowed comment: "Real radios have motors !"

Geoff Fors
WB6NVH