[MRCA] [ARC5] Jeeps with Radio Equipment

Thu Jul 29 13:56:32 EDT 2021

Maybe G.I. Ham put a PE-103 in there to provide the transmitter/modulator
HV directly from the 6 V battery?  I'm sure PE-103's were available in 1950
when that pic was taken...
I've learned to "never say never" in this business!  hihi

Tim
N6CC

On Thu, Jul 29, 2021 at 7:16 AM MARK DORNEY via MRCA <mrca at mailman.qth.net>
wrote:

> To keep the Jeep batteries charged, a generator of some sort needs to be
> mounted somewhere in the Jeep, along with some sort of voltage regulator to
> keep the batteries from being overcharged . The WW2 Jeep  factory set up,
> at least initially, for a 12 volt MB or GPW involved installing a second 6
> volt battery, generator and voltage regulator. This was later replaced by
> use of a 12 volt system for the entire vehicle, as the dual battery system
> added both cost and complication ( there isn’t a lot of room to add a
> second electrical system in a Jeep). The same is true for the larger 3/4
> ton WC series ( the second battery was installed in the front, passenger
> side tool box, along with the radio connection box in the factory set up).
> But especially in the Jeep, there simply isn’t any room to do add too much
> to the vehicle. It is true that the Jeep was set up to accept a PTO, but
> the only issue Jeep that actually had an issue PTO was the GPA Amphibian,
> and they were relatively rare. The only other way I could think of to
> operate the radios without modifying them would be to have either a gas
> generator mounted, or scrounged aircraft APU mounted in the Jeep or towed
> on a trailer behind the Jeep, and I see neither in the photo ( perhaps
> there is a trailer that went with this Jeep that isn’t in the photo ).
> Also, ARC-5/SCR-274 was designed for aircraft use. The radio gear, with
> it’s thin aluminum casing,  isn’t designed to take the beating it would get
> on the ground in the field. That alone points more to a ad-hoc radio
> installation devised and done in theatre. Take a close look at the way the
> aircraft radios are mounted in the Jeep in the photo. It looks “home-made”.
> This mount was done in theatre to fill a specific need at the airfield.
>
> It is easier and more likely that the aircraft radios were modified to
> operate on 12 volts than the Jeep converted to operate on 24 volts. An
> enterprising Ham ( and we all know that Ham operators were highly sought
> after by the US Navy and USAAF during WW2 ) more than likely converted the
> radios in this case to 12 volt. Take a look at what radios in this series
> are left for sale today, and we’ve all seen evidence of enterprising Hams
> modifying these radios to suit their own needs. That was not limited to
> post-war operation. There are photos of scrounged aircraft radios
>  installed in airfield Watch Stations at USAAF airfields in England during
> the war. These radios supplemented the airfield’s radios ( there was a
> transmitter and receiver, I believe a BC-639 and BC-640, at each field,
> along with another station set up to aid radio navigation in bad weather in
> the TO&E for each airfield ). These aircraft radios were scrounged from
> supply, more than likely from aircraft that came back too badly damaged to
> be put back in the air. Of the set ups I’ve seen pictures of in Watch
> Stations, there is a battery bank of four, 6 volt batteries set up to power
> these radios. I did not see how these batteries were re-charged, but more
> than likely there was some sort of electrical battery charger scrounged for
> purpose stored somewhere at the watch station, and somebody on a shift
> who’s duty it was to regularly recharge these batteries.
>
> Mark D.
> WW2RDO
>
> “In matters of style, float with the current. In matters of Principle,
> stand like a rock. “.   -   Thomas Jefferson
>
> Sent from my iPhone
>
> > On Jul 29, 2021, at 4:31 AM, Robert Downs <wa5cab at cs.com> wrote:
> >
> > Mark is correct about the probable date that the photo was shot and the
> Jeep is either an MB or a GPW with 6 volt internal electrical system.  It
> has a 2-piece wind screen.
> >
> > However, although the Command Set receivers can, with a little rewiring
> and/or tube swaps, be operated from either 12 or 6 volts, the transmitters
> cannot.  At least within the limits that the AAC would have imposed.  There
> were never any 6 or 12 VDC relays or transmitter dynamotors built and in
> the supply chain.  Although I have heard that there was a 12 volt
> conversion kit procured in very small quantities, I have never heard that
> there was a 24 volt kit.  But the Jeep has to have at least a 24 volt
> battery in it somewhere.  Most likely, as it could have been requisitioned
> at the time, the Jeep has one of the auxiliary PTO driven generator and
> batteries installed.  The angle at which the photo was taken hides the
> evidence.
> >
> > Robert Downs
> >
> >
> > -----Original Message-----
> > From: arc5-bounces at mailman.qth.net [mailto:arc5-bounces at mailman.qth.net]
> On Behalf Of MARK DORNEY via ARC5
> > Sent: Thursday, July 29, 2021 01:57
> > To: Bill Pileggi
> > Cc: arc5 at mailman.qth.net
> > Subject: Re: [ARC5] Jeeps with Radio Equipment
> >
> > The negative of the photo was received in 1950 from some unit’s records.
> The photo was taken in Iran, more than likely sometime during WW2, since
> the B-24 and it’s subtypes we’re removed from  service when World War Two
> ended.
> >
> > Mark D.
> >
> > “In matters of style, float with the current. In matters of Principle,
> stand like a rock. “.   -   Thomas Jefferson
> >
> > Sent from my iPhone
> >
> >> On Jul 29, 2021, at 1:41 AM, Bill Pileggi <wpileggi at juno.com> wrote:
> >>
> >> Slightly over 10 years ago (June 2011) , there was a mention on this
> list of a photo of a Jeep with ARC's in the rear deck. At the time, they
> would have provided a link. Don't know what the link is now... Nobody seems
> to have brought it up... As a bonus, there's a B-24 in the background.
> >>
> >> So, I'm attaching. It's about 89 Kb.
> >>
> >> Bill KA3AIS
> >
>
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