|
Tube DIY Asylum Do It Yourself (DIY) paradise for tube and SET project builders. |
|
|
|
Tube DIY Asylum Do It Yourself (DIY) paradise for tube and SET project builders. |
|
In Reply to: Re: Why do I have DC on my cathode-biased input tube's grid? posted by mikeyb on April 27, 2007 at 11:03:35:
This is a paralleled triode, so having a 120K plate resistor and 680 cathode resistor amounts to 60K plate load and 1360 ohm Rk's.So looking at the datasheet you posted, closest design is Vp 200, Rp 47K, Rk 1K5. Whopping 8.5% distortion! Yikes!
So I had .4 volts on the tied cathodes, which works out to .58 ma, or .29 ma per triode, which is about a third of the .89 listed on the datasheet. Is this another indication of a bad tube?
...fwiw, a priest told me the tube tested good, yes, a priest, who sells tubes on ebay in his spare time... hmm, maybe I will try another when I get home tonight!
This post is made possible by the generous support of people like you and our sponsors:
Follow Ups
- Thanks for the link, but... - Alexo 11:29:36 04/27/07 (3)
- Hmm actually... - Alexo 11:39:22 04/27/07 (2)
- Actually, actually... - Alexo 11:42:52 04/27/07 (1)
- And put in a 200K Grid Leak Resistor (nt) - Chris O 13:02:57 04/27/07 (0)
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2024, Audio Asylum, all rights reserved ]
