[Johnson] common problems / upgrades for a valiant.

[Dave Maples]

All: For what it's worth, I found I was able to sneak a cartridge-type
fuseholder through the chassis right behind one of the large transformers on
the rear (I think it was the power transformer, but it has been too long).
That and a 3-wire power cord makes for a neat install, I think.

Mine still chirps, though; I think something is coming through the bias
line, but I'm really not certain.  Too much going on around here to dig
deeply, but maybe someday...

Dave WB4FUR

-----Original Message-----
From: johnson-bounces at mailman.qth.net
[mailto:johnson-bounces at mailman.qth.net]On Behalf Of Glen Zook
Sent: Saturday, November 07, 2009 10:54 AM
To: Johnson at mailman.qth.net; w1cjf at verizon.net
Subject: Re: [Johnson] common problems / upgrades for a valiant.


First of all, don't replace the tubes just to replace them.  Tubes last for
decades and there is a very good chance that most of them, if not all of
them, are still good.

The paper type capacitors (including those encased in plastic) are almost
certainly leaky (such capacitors go bad even when brand new, never installed
in a unit).  There is also a very good chance that the electrolytic
capacitors have gone bad.  Although there are people who try to "reform" the
capacitors I have found that it is generally best to just go ahead and
replace them.  Modern equivalents are much smaller than the original
capacitors, have closer tolerances, and are more reliable.

There is an 18K resistor in the VFO compartment that often goes bad (it is
really pushed to the limit) and should be replaced with the same value but
of a higher wattage.  Some people say to remove this resistor from inside
the VFO.  However, various people have tried experimenting with the resistor
both inside and outside of the compartment and have come to the conclusion
that the VFO frequency stabilizes much sooner if the resistor is left inside
the compartment.

Clean the switches and potentiometers.

Replace the power cord with a 3-wire cord making sure that the green wire is
connected directly to the chassis of the transmitter.  The black wire of the
power cord needs to go to the fuse and then to the off/on switch.  The white
wire needs to go to the "other" side of the original power cord.

Glen, K9STH

Website:  http://k9sth.com


--- On Fri, 11/6/09, w1cjf at verizon.net <w1cjf at verizon.net> wrote:

How is it going? I am chris and i am 28 years old from rhode island. I just
picked up a absolute drop dead sexxy valiant from a local on craigslist. I
am the 3rd owner as the previous one was given this valiant from his uncle
who bought it new, as a kit it looked liked to me. As every tube along with
other markings on the case for what does what. All notes were done in
pencil.

As i am going through it now cleaning it up and stuff, i am wondering what
common problems do I need to be made aware of so i can take care of them
now? I have heard of something with the band switch but i am not certain
what the problem is and the fix for it. This has the STOCK tubes in it and
has never been re-tubed. This is the first thing i am going to take care of,
along with the power cord which the shielding has fallin right off of the
cable itself.

The caps are not leaking which is a good thing i guess, but i think i will
need to change them down the road. I know I am young but i just love these
damn things, I have had offers to trade it for a newer style radio ie a 746
PRO but it will never happen.



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