Melos Sha Gold - Page 2

anatech · 28th March 2006, 11:03 PM

Hi ManUtd,
When it rains ....

Okay, so measure the plates, grids and cathode connection to start.

-Chris

ManUtd · 29th March 2006, 09:12 AM

Quote:

Originally posted by anatech
Hi ManUtd,
When it rains ....

Okay, so measure the plates, grids and cathode connection to start.

-Chris

I Have measured this results (DC) directly on Tube.All are measured after 1 Minute On-time.Pin 1 =Rising to 90V and drops down to 75,5V.Pin 2 Rising to 125mV (hmmm!).Pin 3 0,75V
Between Pin 4 and 5 i got 2,9V.Pin 6 Rising up to 92V and drops down to 86V.Pin 7 135mV (hmmm!).
Pin 8 0,76V.

What about pin 2 and 7 are these normal? Could it be leakage in a capacitor?

Reg,
ManUtd.

anatech · 30th March 2006, 12:42 AM

Hi ManUtd,
Pins 2 and 7 are not referenced to ground. So this could be perfectly normal for this unit.

I looked at the current source reading and want you to reconfirm for me. I calculated a cathode current of 0.88 mA for both sections. That is current starved. The first section is running with a grid voltage of -0.625V and the second section is -0.625V wrt the cathodes. A very low value that supports the low cathode current observaton. There may be a problem here.

-Chris

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28th March 2006, 11:03 PM	#11
anatech diyAudio Moderator Join Date: Jun 2004 Location: Georgetown, On	Hi ManUtd, When it rains .... Okay, so measure the plates, grids and cathode connection to start. -Chris

30th March 2006, 12:42 AM	#13
anatech diyAudio Moderator Join Date: Jun 2004 Location: Georgetown, On	Hi ManUtd, Pins 2 and 7 are not referenced to ground. So this could be perfectly normal for this unit. I looked at the current source reading and want you to reconfirm for me. I calculated a cathode current of 0.88 mA for both sections. That is current starved. The first section is running with a grid voltage of -0.625V and the second section is -0.625V wrt the cathodes. A very low value that supports the low cathode current observaton. There may be a problem here. -Chris