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37-670 No Sound
#7

(03-10-2016, 06:20 PM)dfields69 Wrote:  
(03-10-2016, 06:17 PM)dfields69 Wrote:  
(03-10-2016, 05:04 PM)Radioroslyn Wrote:  >The 200 ohm section that appears to handle the plate voltage for two 6J5 "driver" tubes is not generating a reading. Does that mean it is open/bad and what may I do to rectify the situation?

If there is no plate voltage on the 6J5 then the answer is yes. Well there is two answers. One you could replace the driver transformer. Or connect a resistor across the primary(like 70k or so ) and then connect the cap(like a '01 @630v) from the plate of the 6J5 to one of the grid connection on the transformer secondary.

Replacing the transformer is more efficient but adding the resistor and cap is much easier/cheaper.

Terry
What wattage on the 70K resistor? 1 watt or higher? And the grid connection would be the low ohm sections that go to the input grids on the 6F6's? I have never, ever fooled with one of these so pardon all of the questions. Terry, you have consistently come to my rescue here and I am very grateful! I sure wish i could return the favor somehow...thanks again!

And Radio Daze as well sells a Hammond 124 series interstage transformer. Were I to replace it, which of those would I go with?? The 124D looks close as a novice, but I am very uncertain.
I think the 124D is a good choice but I not quite sure what sort to turns ratio we need. It's at 1 to 1:5. The higher the ratio the higher the ac signal will be at the 6F6 grids. The 6F6's are triode connected (plate and screen grid are connected together) which lower the gain of the tubes. So typically it requires more driving signal.
The transformer Mike suggested I think is a single plate to P/P grids. Won't work no tap on the primary. Yours is P/P plates to P/P grids.

Terry


Messages In This Thread
37-670 No Sound - by dfields69 - 03-10-2016, 03:03 PM
RE: 37-670 No Sound - by Radioroslyn - 03-10-2016, 05:04 PM
RE: 37-670 No Sound - by dfields69 - 03-10-2016, 06:17 PM
RE: 37-670 No Sound - by dfields69 - 03-10-2016, 06:20 PM
RE: 37-670 No Sound - by Radioroslyn - 03-10-2016, 07:38 PM
RE: 37-670 No Sound - by Radioroslyn - 03-10-2016, 07:21 PM
RE: 37-670 No Sound - by morzh - 03-10-2016, 07:19 PM
RE: 37-670 No Sound - by morzh - 03-10-2016, 08:02 PM
RE: 37-670 No Sound - by dfields69 - 03-10-2016, 08:24 PM
RE: 37-670 No Sound - by Radioroslyn - 03-11-2016, 12:38 AM
RE: 37-670 No Sound - by dfields69 - 03-11-2016, 02:19 AM
RE: 37-670 No Sound - by Mondial - 03-11-2016, 09:42 AM
RE: 37-670 No Sound - by dfields69 - 03-11-2016, 12:59 PM
RE: 37-670 No Sound - by Mondial - 03-11-2016, 03:37 PM
RE: 37-670 No Sound - by dfields69 - 03-12-2016, 02:16 AM
RE: 37-670 No Sound - by dfields69 - 03-12-2016, 02:17 AM
RE: 37-670 No Sound - by Mondial - 03-12-2016, 09:53 AM
RE: 37-670 No Sound - by dfields69 - 03-23-2016, 05:10 PM
RE: 37-670 No Sound - by morzh - 03-23-2016, 07:06 PM
RE: 37-670 No Sound - by Radioroslyn - 03-23-2016, 07:30 PM
RE: 37-670 No Sound - by davemc - 03-24-2016, 08:07 AM
RE: 37-670 No Sound - by Ron Ramirez - 03-31-2016, 09:58 PM
RE: 37-670 No Sound - by dfields69 - 03-31-2016, 11:37 PM
37-670 Continued Woes - by dfields69 - 03-31-2016, 09:47 PM



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