[Johnson] common problems / upgrades for a valiant.

[Glen Zook]

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.