Thread: Ts4d Motorola
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Old 04-07-2018, 03:13 PM
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timmy timmy is offline
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Quote:
Originally Posted by dieseljeep View Post
Sorry, those are penthodes, the 6SR7 is almost the same tube as the 6SQ7, but with a lower mu or amplification factor. A triode with detector plates, all tied to ground or B-.
I looked at the schematic again and the 22 ohm resistor across the heater of the 6SQ7 is located in the ballast tube. Insane!
Yes that resistor is in the ballast or it was now it's separate on the chassis. I mentioned that resistor because the Manuel spoke about audio hum so I double checked that resistor to make sure I didn't put the wrong leg to it but it's good. I went over the Power supply and it all looks good. I'll probably wind up just dealing with this hum which I really do want to I would rather find the cause. If the speaker was 15 ohms the hum would be much less but the original speaker is 3.5 ohms and compared to the higher ohm speaker it would be so much more quite. The speaker I was using is 15 ohms rather then taking the one out of the cabinet.

Last edited by timmy; 04-07-2018 at 03:39 PM.
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