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Title: Tested 4 of my 13 813's today Post by: w1vtp on October 26, 2013, 08:29:26 PM 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 Title: Re: Tested 4 of my 13 813's today Post by: KB3DKS on October 28, 2013, 09:59:19 AM What test parameters are you using?
Title: Re: Tested 4 of my 13 813's today Post by: w1vtp on October 28, 2013, 10:22:16 AM 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 Title: Re: Tested 4 of my 13 813's today Post by: KB3DKS on October 28, 2013, 10:44:30 AM 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 Title: Re: Tested 4 of my 13 813's today Post by: w1vtp on October 28, 2013, 02:03:02 PM 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 |