Tested 4 of my 13 813's today

[w1vtp]

Thanks to Steve, W2TRH for the loan of his 813 tester.  3 tested really good, 1 was good but not so high as the others.  Onward to the other 9 813's.  Last time I knew, all were essentially new.  Some in box the rest carefully wrapped and stored.  Life is good. Gotta get with that push pull 813 modulated with triode connected 813's

Al

[KB3DKS]

What test parameters are you using?

[w1vtp]

What test parameters are you using?

Steve, TRH would know that.  I was told a variable 800 volt plate supply on a Variac is one parameter and I believe the screen voltage is also available on its own variable supply.  I'm guessing the CG is tied to ground - but that's a guess.

All of my tubes tested high emission with only one "sparkler."

Al

[KB3DKS]

Al,
OK, close to what I did awhile back. Used a regulated 1kv variable plate supply, a screen supply set to the textbook voltage and had a ma meter in the grounded grid connection so there was a small bias from that. Found most of my 813s were OK with a couple obviously beat up ones a bit weak. Used the same setup for some 814s and found a couple gassy ones. They lit up real nice inside.
Bill

[w1vtp]

Al,
OK, close to what I did awhile back. Used a regulated 1kv variable plate supply, a screen supply set to the textbook voltage and had a ma meter in the grounded grid connection so there was a small bias from that. Found most of my 813s were OK with a couple obviously beat up ones a bit weak. Used the same setup for some 814s and found a couple gassy ones. They lit up real nice inside.
Bill

Bill

I had just that one sparkler.  The rest tested like new so I'm a happy camper.  I have a spare for my ART13 and spares for the 813 transmitter.  Decades of pack ratting has paid off.  OH, one of those tubes was a pull out of my Eldico TR-1 which I (sadly) no longer own.

Now that I think of it - I have yet to test the 813 in my ART13.  That'll be cone ASAP


Al