[Motorola] Research Line for amateur use

[Glenn Little]

I think that I still have two of the Mark 12 UHF phones in the 
garage.  Along with a MOTRAN that I think was for setup for marine use.

I built a HT220 from Spectronics boards.  Even fixed a few of their $15.00 
broken boards. The ones that were snapped in half to keep them out of 
commercial service.  The latest HT220 that I built would have been a super 
SP.  It had an E front with touchtone pad and the marine option PA 
deck.  Used the PL switch for Power Level. This was a 6 channel 
radio.  Even went so far as to get a 8 position switch from Grayhill, but 
never installed it.

Until recently we were using MOCOM 70 UHF radios for linking some of our 
repeaters.  They worked ok until we had a connector problem.  The SWR 
sensing is between the VHF pA and the Varactor.  Nothing between the 
Varactor and the antenna.

Mororola really produced a wide range of radios. Some better than 
others.  Most quite good in their day.

73
Glenn
WB4UIV

At 07:52 PM 3/21/02 -0800, you 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
>
>_______________________________________________
>Motorola mailing list
>Motorola@mailman.qth.net
>http://mailman.qth.net/mailman/listinfo/motorola

---------------------------------------------------------------------------
Glenn Little                         glittle@awod.com   QCWA  LM 28417
Amateur Callsign:  WB4UIV            wb4uiv@amsat.org   AMSAT LM 2178
QTH:  Goose Creek, SC USA (EM92xx)                      ARRL  TAPR
---------------------------------------------------------------------------