Correct Pins For EL84 Triode Strap

[TV Man]

Want to be sure about this so as not to blow anything up

Triode strapping the EL84 with a 100 ohm resistor from the anode to grid2 looks to be pin 7 to pin 9. Am I seeing this correctly?

Also, how many watt resistor should I use.... 1/2 watt, 1 watt, higher?

Been searching for this info and I'm sure it's in the forum somewhere, but can't find the specifics readily.

Thanks

 

[Tubes4e4]

Hi,

Triode strapping the EL84 with a 100 ohm resistor from the anode to grid2 looks to be pin 7 to pin 9. Am I seeing this correctly?

Yes, connect pin 9 to pin 7.

Also, how many watt resistor should I use.... 1/2 watt, 1 watt, higher?

There is no reason whatsoever to use a grid stopper resistor in this case, just bridge the few milimeters between pins with a wire.

Regards,

Tom Schlangen

 

[richwalters]

Tom,
Have you ever plotted the 12BY7 and 12GN7 in triode mode ?
These are a straight as could be. I'm getting brilliant results.

richy

 

[Tubes4e4]

Hi Richy,

Have you ever plotted the 12BY7 and 12GN7 in triode mode ?

Sorry, but no. These types are quite unusual and rare over here, I didn´t even know 12GN7 does exist. Another example how different the "standard sets" of tubes in a TV set were in USA and Europe, I suppose.

These are a straight as could be. I'm getting brilliant results.

Thank you for this information!

Tom

 

[richwalters]

Yes your'e right. Just before the end of video tube era, the market was awash with all sorts. I've enclosed a rough plot of the 12GN7. I'm interested at the low current end, so the high current curve is not here. and the P curve has nearly disappeared to the right end.
Similiar to the 12BY7 (this has a bit softer curves), the pinning is identical. The EL822 ; EL83 are European candidates.
As you know, the drawback of extremely high gm is tube electrical tolerance can be unpredictable.
Anyone using these tubes for audio, note they aren't screened and can be microphonic, BUT they are linear and produce very low thd. For CCS nothing could be better !

richy