[Johnson] Valiant mod query

Glen Zook via Johnson johnson at mailman.qth.net
Thu Jul 16 10:22:44 EDT 2015


It is definitely possible to do this conversion.  Heath did this for the original DX-100 with the MK-3 modification kit and I have seen this done in examples of the WRL Globe Champion 300, 300A, 350, and 350A.
The instructions for the Heath MK-3 kit are included in the article at the following URL:
http://nebula.wsimg.com/a299627e256e4c19a81224d1bd62bb46?AccessKeyId=5DDC3F25F0398F58962E&disposition=0&alloworigin=1

I would use a 3, or 4, section broadcast variable capacitor (nominally 365 pf per section) as a minimum.  It has been my experience that such a broadcast variable works fine as the loading capacitor for transmitters with up to at least around 300-watts output.  Transmitters, with higher power output, sometimes need plate spacing a little wider to prevent arcing under high SWR conditions. Glen, K9STH

Website: http://k9sth.net
      From: John Neeley <w6zkh at att.net>
 To: "johnson at mailman.qth.net" <johnson at mailman.qth.net> 
 Sent: Thursday, July 16, 2015 8:50 AM
 Subject: [Johnson] Valiant mod query
   
Since I am unable to locate and replacement for the Aux Coupling Switch (SW6) for the Valiant, I am wondering if anyone has every replaced that switch and caps with a variable cap in its place?  Somewhere I have heard of it, but never any details, i.e., size, capacity of variable, etc.  Or, am I just wasting my time and just junk this rig?  Even as it sits, I can still use it, but not loaded to full output...  Any ideas would be appreciated.

  


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