Viking II question - triode connecting the 807s

[W2VW]

The old Tektronics scopes which weighed a ton used 6080s.

[WA1GFZ]

ah yes the 545

[KE6DF]

Just a thought to ponder:

Has anyone ever thought about using 6080s as modders? ? They would prolly need a lot of grid drive, but they have the lowest plate resistance of any tube I know of.
And they are designed to handle high plate currents.

There are plenty of schematics for using 6080's as audio amplifiers out there on the tube audio sites.

They supposedly work very well.

About 8 or 9 watts output from push pull circuits in class a. 2K output impedance on the output transformer.

That would be more than plenty for 807s and perhaps you could parallel two 6080s and drive tubes like 805s. Sure would be cheaper than 2A3s.

[k4kyv]

Jim, I'd say your beam deflection theory is right. Maybe the deflection plates aim electrons directly to the plate and away from the screen, allowing the plate voltage to drop to a lower value.  I have some articles on the theory of how beam deflection tubes work that I'll have to review.

I don't have any 6080s, but I do have a bunch of 6AS7Gs, a similar tube.  The problem with using the 6AS7s is the maximum plate voltage rating.  IIRC, it's something like 150 volts. I have used 6AS7s as bias regulators, but never tried them as class B drivers.  They ought to work well in a lower power modulator that requires less grid voltage swing.

Fortunately for me, I had already accumulated an adequate supply of 2A3 spares long before the audiophools discovered them.

[KE6DF]

I don't have any 6080s, but I do have a bunch of 6AS7Gs, a similar tube.  The problem with using the 6AS7s is the maximum plate voltage rating.  IIRC, it's something like 150 volts. I have used 6AS7s as bias regulators, but never tried them as class B drivers.  They ought to work well in a lower power modulator that requires less grid voltage swing.

Here is a schematic for the 6as7 as a push pull audio amplifier dating all the way back to 1949.

It uses a tube rectifier with a 800v ct power transformer and two stage choke input filter. So it must be running on something in the 250 - 300v range.

Perhaps the tube can handle a bit more voltage in this type of circuit.

http://www.bonavolta.ch/hobby/en/audio/6as7_1.htm

Dave

[WD5JKO]

Here is a schematic for the 6as7 as a push pull audio amplifier dating all the way back to 1949.
http://www.bonavolta.ch/hobby/en/audio/6as7_1.htm
Dave

  Dave, It is always cool to see these old circuits. I wonder though, the 6N7 audio driver plate load resistor, R6 0.1 meg-ohms, seems like a typo. I bet it was supposed to be closer to 5-10K WW power resistor.. It just doesn't look right with such a high resistance as a plate load on a high level audio driver tube.

Jim
WD5JKO

[Steve - WB3HUZ]

Use a 6336 instead. Good for 400 VDC.

Jim, I'd say your beam deflection theory is right. Maybe the deflection plates aim electrons directly to the plate and away from the screen, allowing the plate voltage to drop to a lower value.  I have some articles on the theory of how beam deflection tubes work that I'll have to review.

I don't have any 6080s, but I do have a bunch of 6AS7Gs, a similar tube.  The problem with using the 6AS7s is the maximum plate voltage rating.  IIRC, it's something like 150 volts. I have used 6AS7s as bias regulators, but never tried them as class B drivers.  They ought to work well in a lower power modulator that requires less grid voltage swing.

Fortunately for me, I had already accumulated an adequate supply of 2A3 spares long before the audiophools discovered them.