[Milsurplus] Power Supply Question

[Morrow, Michael A.]

From: William Hooper

> The designation is:
>=20
>             POWER SUPPLY PP-109/GR
>=20
> Looks like a dual-voltage input with a lot of pins on the=20
> output connector.  Does anyone recognize
> this supply and remember what it was intended to power? =20
> Voltages output etc. ?

That's the 12 vdc input vibrator power supply for the RT-66, -67, and =
-68/GRC Korean War era FM sets (20 to 55 mcs).  It was used in the =
AN/GRC-3 through -8, the AN/VRQ-1 through 3, the AN/VRC-8 through -10, =
and -13 through -22, IIRC.  I don't have my manuals with me, and I don't =
remember all the output voltages.  It has two "high" HV outputs, =
depending on whether high or low transmitter power is selected, and one =
lower HV output for the receiver voltages.  Three vibrators total, IIRC. =
 Also, it reduces the 12 vdc input voltage to the 6.3 vdc heater/relay =
voltage required by the RT.  It uses a bunch of glass ballast tubes and =
thermal relays to regulate the LV, so that's what a lot of those =
tube-like things that aren't really tubes do in the PP-109.

I use the 24 vdc version, the PP-112/GR, in my AN/GRC-7 set.

I've always felt that this series of radios was pretty advanced for its =
late 1940s to late 1950s era, but it seems few military radio collectors =
have much regard for them.  Still, a full-blown AN/GRC-7 (RT-68, RT-70, =
R-110, PP-112, PP-282 (2), AM-65, C-435, C-375, and MT-297) is a pretty =
visually impressive 225 pounds of radio set.  (Much more so than my =
AN/VRC-47 (R-442A, RT-524A) set.)

Fair Radio has the PP-109 for $35.

73,
Mike / KK5F