[Johnson] Looking for resources and possibly some help . . .

[Richard Knoppow]

    I am a little skeptical about replacing vacuum tube 
rectifiers with silicon diodes. Mainly because of the much lower 
voltage drop of the diodes. Vacuum tubes drop tens of volts while 
a diode drops perhaps 1.5V. Not always a problem but makes me 
worry about the voltage limits of components and tube dissipation.
    Replacing mercury or gas rectifiers is not so bad because 
they all have a fixed drop of around 15 volts. Since they are 
usually used for high voltages there is no drawback in using a 
series of diodes to add up to the tube drop. A series resistor 
and diode will not duplicate a vacuum rectifier because the tube 
internal resistance is not linear with current.
    I used to be concerned with the nearly instant application of 
DC from diodes but found that vacuum tubes apply output voltage 
very quickly even without the filaments being fully heated. Look 
at anything with a voltage regulator tube in it, usually they 
will begin to glow as soon as the AC is applied.
    I do agree that if you use diodes they should go on the 
socket pins and the socket covered over with something.
On 5/18/2019 7:27 PM, qrv at kd4e.com wrote:
> Will do, thanks!
> 
>> Check the underside, the Rectifiers could be soldered to the 
>> tube pins.
>>
>> 73, Dick, W1KSZ
>
-- 
Richard Knoppow
1oldlens1 at ix.netcom.com
WB6KBL