[Amps] Plate Bypass Capacitor

[Glen Zook]

You may be thinking of the 6293 which is a special version of the 6146 that was made for pulse modulator service.  The 6293 can take up to 3000 volts on the plate.

Also, the 6293 is an excellent replacement for the 6146 and 6146A/8298 and will generally last between 5 times and 10 times longer than the 6146 and 6146A/8298 when run using the same parameters.  The prices for the 6293 are usually about the same as for the 6146 and 6146A/8298 from the various tube "sellers" on the Internet.

Also, the 6146 and 6146A/8298 are rated at 600 volts maximum when used in plate modulated AM service.

The 6146B/8298A is really a different tube from the 6146 and 6146A/8298.  The 6146B/8298A is rated at 120 watts input for Class C in CW and FM service, at 120 watts input for AB-1 and AB-2 (for SSB service), and at 90 watts input for Class C plate modulated service.

Glen, K9STH

Website:  http://k9sth.com


--- On Thu, 8/6/09, Manfred Mornhinweg <manfred at ludens.cl> wrote:


Not so...! I just checked datasheets for the 6146 (no suffix), for the> 6146A and the 6146B, from RCA and GE. They all agree on the plate voltages: 600V in CCS, and 750V in ICAS!
 
The 400V rating in the RCA 6146 datasheet is only valid for a special situation: Audio amplifiers which have the screen grid directly connected to the plate!
 
But now it's time for me to admit a mistake too: Somehow I was thinking that the 6146 series was rated for up to a kilovolt on the plate. That might be because in my young hotgun years I used to run them that way.  With good cooling, and watching the plates, I got 160 to 180W PEP clean output in SSB from a pair of 6146B, ran from a power supply that gave 950V at no load, and of course dropped some at full load. The tubes are still good today! That speaks of their quality. I didn't use a speech processor, though. Using one might have melted the tubes!