[Johnson] DO NOT Solid State the Power Supply in your Ranger!!

[Sherrill Watkins]

Dear Ross: Consider yourself lucky! My Drake TR-4C has solid state power
supply and will seriously weaken many of the tubes in about 12 to 18 months.
Of course, the number of on-off cycle times has a lot to do with this.
-73-Sherrill W. k4own.

-----Original Message-----
From: Ross Stenberg [mailto:k9cox at charter.net] 
Sent: Monday, October 18, 2004 10:43 AM
To: Sherrill Watkins; Johnson at Mailman. Qth. Net
Subject: RE: [Johnson] DO NOT Solid State the Power Supply in your Ranger!! 


Interesting Sherrill, my Hallicrafters SX-117 tube radio, Heathkit SB-101,
and Hammarlund HQ-170A all have solid state rectifiers in the factory
versions as do many others from that era. The B+ is applied immediately and
they are still working well! Large power transmitting tubes with specific
filament designs are another story.

	73 Ross K9COX

>>Dear Tim: I wished you had researched this matter before you did the 
>>work.
It
is a serious mistake to solid state the power supply in any tube radio.
Several months ago I posted comments and reasons to this effect on this
reflector. This was based on the cautions and warnings that have appeared in
several article that were published in ELECTRIC RADIO MAGAZINE and The OLD
TIMERS BULLETIN. By doing so you are creating additional stress on all the
electronic components, creating more heat and damaging all the tubes because
of electron stripping from an instantaneous application of B+ before the
electron cloud has formed properly around the cathode. I urge you to change
it back to the original vacuum tube type! Also, do not allow the AC line
voltage to exceed 115 vac. (I don't care how many people have converted their
power supplies to solid state, it is NOT recommended by those that really
know vacuum tube technology and is based on fact! I you do not believe me,
then read the articles!) -73-Sherrill W. k4own.