[Boatanchors] R-390A FIX FOR THE 3TF7 PROBLEM

[Craig C. Heaton]

Bill,

I'll place my vote with the 12BA6's used for the PTO/BFO and a jumper
between pins 2 & 7 on the ballast tube socket. Two R-390/A in my shack have
been running that way for several years, no problems.

One of them had the 12BY7 mod, I removed the mod! Can't remember the
details, but the tube socket for the ballast tube is wired different.

Craig,

-----Original Message-----
From: boatanchors-bounces at mailman.qth.net
[mailto:boatanchors-bounces at mailman.qth.net] On Behalf Of William Kipping
Sent: Saturday, October 11, 2008 3:07 PM
To: boatanchors
Subject: [Boatanchors] R-390A FIX FOR THE 3TF7 PROBLEM 



Hi to All 
 I recently purchased an R390A, (my first)  No surprise the 3TF7 ballast
tube is open. I know of the three easy fixes,(45ohm 10w resistor, or a
jumper and use 12ba6s in the pto/bfo, or use a 12BY7 as a load)   Thought 
I would ask for recommendations on which to use. Also if using a 12BY7 as
the filament load fix , are any other jumpers needed on the tube socket or
just a plug in Thanks for your advice Bill KE7KK  

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