[SignalOne] Intro

jerry jerry at tr2.com
Thu Oct 31 12:30:02 EDT 2024


Hello!

    I just scored an INOP CX7A on Ebay.  
https://www.ebay.com/itm/204853840353

    Description is "powers up but does not transmit or receive".  That's 
all I know.
The serial# tag is missing.  By "powers up" I imagine they mean that the 
meter lamp
glows and the Nixies light.  So at least a couple of the power supply 
voltages work.

   It's been modified to a modern AC line cord connector.  The Ebay pix 
don't seem to
show the power supply.  The innards look a little dusty, but they're all 
there.

   I have been a ham since 1970.  As an impoverished highschooler, I 
could not *dream*
of owning one of these.

   My main interests are homebuilding and repairing.  I hope I haven't 
bitten off more than
I can chew with this one.  I have pretty good background in electronics; 
  in the late 70's and
early 80's I worked as a tech for 5 years, first on a production line, 
then repairing test
equipment.  I built my first SSB transceiver ( never got it working ) 
around 1970, and my first
linear in 1971.  It was 4 6LQ6 tubes stuffed into an ARC5 transmitter 
cabinet.  Recently, I built
a kilowatt LDMOS linear that is in daily use, and a multi-mode HF 
transceiver that I just did the
very first QSO with last night.  Been working on that one for FOUR 
years.

   They're shipping the CX7A today.  I am preparing by reading the 
barrels & buckets of great
info on the hamanuals site, including the manual.  I also ordered a 
paper one from the same Ebay
guy.  I cleared off the workbench in the garage.  I identified space in 
the shed for one of my
vintage stations, to make room for the 'One in my office/shack/playroom. 
  Either the KWM2/30L1
station, or the Drake TR7.  Possibly the TR7.  Winter's coming, and the 
30L-1 makes a nice space
heater ( with radio as a side effect ).

   I also ordered a pair of NOS RCA 8072 tubes, and a couple of 40673's.

   Plan to upgrade the PS to three-terminal regulators per the 1977 CQ 
magazine article.  Anybody
here done that?  Are the instructions accurate?

   I think the first thing to do is to give it a good cleaning.  Have a 
couple quarts of isopropyl
alcohol ready and a box of Q-tips.   And DeOxit - "Radio repair in a 
can".  Although I mostly use a little
bottle with a needle tip.  Not good to spray that stuff everywhere.  And 
of course the "fader" variety for
the pots.

   Need to review Respect for High Voltages.  I've gotten spoiled in 
recent years with solid state equipment
that can't kill you.

            - Jerry, KF6VB



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