WorldwideDX Amateur Radio Forums

I have been doing some researce,and I see if not mistaken. I can take a 8950 tube and exchange the heater pins 1 & pin 12 from the socket,and place a 6lf6 in and use it in place of the 8950! 6LF6 is just a broke down verson of the 8950 but at 6 volts........any thoughts

6lb6 works fantastic for replacing the 8950, of course heater voltage is different.

2057 will work with no changes,and more output...73s de JW

__________________
FT450d,TS520,RCI2950dx and 2980wx,seven Siltronix 1011d,FT250r ht,motorola maxtrac300 uhf SWAN1200x

Are there any changes to be made to use the 6LB6?

Indeed they will but good luck finding a 2057 at a reasonable price. They are probably the only sweep tube to cost more than the 8950.

Better to do the 6lb6 conversion.

__________________
Too much stuff to list here. But it's all vintage and it all works perfectly.

Yep

The 8950's are going for around $100 or so when you can find them. I don't do cheap tube amps at all myself but all the guys around here are only going with the common cheaper tubes either by design or the above conversions.

__________________
Welcome to the WWRF. Plenty of Free Parking and with 5,000 posts you get egg roll

Yes.
The heaters ( filament ) on the 8950 are 12 volt.
the heaters on the 6LB6 are 6 volt.
If it has an even number of tubes, you can feed two of the 6LB6 heaters in series and do it, or else supply a 6 volt filament transformer.
How many tubes does it have?

73
Jeff

__________________
Radio-active

NASA/SOHO


there is no dark side in the moon, really. As a matter of fact it's all dark

Keep in mind that although the 6LB6 will work as a replacement for an 8950, your power output will drop a little bit, as the 6LB6's are around 33W plate dissipation per tube, vs. 40W plate dissipation for an 8950.


Just tie the filaments in series with the 6LB6's, and you should be good to go. Most of the inter-electrode capacitances are fairly close, so you shouldn't have too much trouble tuning up the amp. Just keep your input wattage down so you don't over-drive the tubes. Good luck!

~Cheers~

__________________
Bases: Cobra 2000 GTL, President Washington, President Madison, Tram D201A
Mobiles: Cobra 146GTL, Midland 79-893 (NIB), Midland 13-893 (27.555), President P300