[R-390] [KA9EGW] s/n 4214 ANT RELAY

[ka9egw at britewerkz.com]

The selenium rectifier [less some of it's magic smoke, judging by the color
of the paint on it] is under the audio chassis.  Two wires going to it match
the color of the two up by the ANT relay.

So...consensus, please?  sand-state bridge, or fuhgeddaboudit?  I can live
with the noise from a silicon bridge, seeing as how it only has power when
the radio is in STANDBY or CAL...in my case it would be useful to put it in
CAL with WWV tuned in, and standby is not indicated due to B+ spiking in
STANDBY if I understand correctly...

This is turning into a project.  My original purpose was to do an evaluation
of the cost-effectiveness of sending hte radio to W3HM.  If I go any farther
I'm going to end up tearing into it myself, for which I have not the time.
OTOH if I could only afford to have Howard do one radio [which given the
local economy around here is entire plausible] it would be my R388--a
graduation gift from my folks in 197x--but that's a topic for a different
list.

-----Original Message-----
From: ka9egw at britewerkz.com [mailto:ka9egw at britewerkz.com]
Sent: Tuesday, September 15, 2009 3:17 PM
To: r-390 at mailman.qth.net
Subject: [KA9EGW] s/n 4214 ANT RELAY


Yep, according to my trusty Keithley 175 bench meter, those two wires show
25VDC/14VAC in standby and cal modes, and nothing the rest of the time,
readings consistent with RAW unfiltered DC.  Inspection of the antenna relay
shows nothing connected to it but 3 mini-BNC's.  Inspection of the schematic
shows no filtering on that line.  Inspectionof the area around the relay
shows no bridge rectifier of any sort close at hand.  Are they driving the
relay coil with unfiltered DC?

73, Brian KA9EGW