[Motorola] Research Line for amateur use

[J.Sharrow]

Hey Geoff, what was the number of the (radar tube) I think you said that you
used in a vhf 41V for better sens ?  I have an old utility vhf base in near mint
condition crystaled on 146.52 but the sens is about .7 or .8uv.  I read your
email and then accidentally deleted it before I got the tube number . OOOPS
Thanks , Jeff , N9OFB

Geoff Fors wrote:

> Jack's note brings up another topic...the Motrans used an inverter power
> supply to run the final transistors at something like 24-36 volts.  That was
> a popular design at the time, other radios such as the GE Porta Mobil I pack
> set portable did the same thing.
>
> I have several of those Motrac accessory tone burst heads in my junkbox; too
> bad they weren't something more useful like multi-PL encoders !
>
> So far I haven't mentioned the Mark 12 UHF radio, also seen as the MK type
> UHF Bell System car phone, with duplexer + supervisory board and 12 channel
> capacity.  I have one of those in the car phone "museum" which was owned
> originally by AT&T Labs.  A surprisingly good performer for a radio with a
> varactor tripler to get to UHF.  The filter system in the RF section was
> said to be a complex affair best left untouched except by the factory.  AT&T
> appears to have been experimenting with this one to make a vehicular speaker
> phone.
>
> Maybe we should start a thread about the weirdest Motorola SP- products
> made... I submit as the first example a 1965 vintage California Highway
> Patrol "5&9 Motrac" which was a 5 channel receive, 9 channel transmit
> "administrator" car low band radio, created out of two long-case "X"
> prefixed Motracs patched together by a "siamese" cable coming out the side
> heat sink panel of each.   I have the manual for one but alas, no radio
> (yet...).
>
> Or how about another weird thread, about "what ever happened to" the used
> two-way dealers which once were with us, such as long-gone Mann
> Communications of Tarzana CA (later Agoura, CA), Gregory Electronics in
> Saddle Brook NJ, or Spectronics in Oak Park, IL.  Then there are the rare
> ones such as DuPage FM of Lombard, IL or Sherman Wolf (he of the FM
> Schematic Digest fame ) plus about two others I have forgotten the names of.
>
> Geoff WB6NVH
>
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