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Re: The "One switch" dilema...

Douglas -

kitsrus kit # 152 (http://www.kitsrus.com/kits.html#k152) is a small digital delay board. Quite inexpensive and adjustable for a wide range of delay periods. Runs off of 12vdc, but I can tell you how to rewire for 5-6vdc with a change of relay and a few resistors.

I use a 20W/3K resistor in series immediately after an 83 rectifier in a 46 based amplifier. I use the digital delay's relay to short the resistor after 16 seconds. You will see a slow initial glow as the 83 starts conducting and starts charging the filter caps, but the 3K resistor will greatly limit the flow and prevents flashing over. After the relay shorts out there is a brief flash as the 83 sees a full load. Works very nicely, and is "wife friendly". The 3K resistor isn't critical, just a "junk box" part that did the job.

Another trick that also works very nicely is a damper diode in series with the mercury rectifier. I believe that Dave Slagle has written about this in the past. The very slow turn on of the damper diode allows the 82/83 to warm up before conducting. Just bridge the damper diode with a high value resistor (around 100K works well) so there is a "ground reference" before the damper diode starts conducting.




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