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

[WA5CAB at cs.com]

I have no personal experience with the problem as all the sets I have had 
still had a working ballast tube.  But all three solutions do away with the 
current regulation function to wash out the heater current change due to varying 
line voltage.  So I would go with the minimum heat load solution, which is a 
jumper and a pair of 12BA6's.  It dissipates half the heat of the other two.


> 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  

Robert Downs - Houston
wa5cab dot com (Web Store)
MVPA 9480


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