Bottlehead Forum

General Category => General Discussion => Topic started by: Yossihaimberg on February 27, 2025, 10:15:34 AM

Title: Voltage at terminals 25 and 30 BeePre [resolved]
Post by: Yossihaimberg on February 27, 2025, 10:15:34 AM

Hi,

Checking the voltage at 25 and 30 shows 0 VDC....  (should be close to 10 VDFC per page 55 of the manual)

All other readings so far were on target:

31 and 33 = 250VDC
Filament out 6.3 VDC on both sides
4 and A4 or A1   445 ohm
14 and B1 or B4  445 ohm


I checked and triple-checked the wiring; they all seem fine.

Please help....

Title: Re: Voltage at terminals 25 and 30 BeePre
Post by: Paul Birkeland on February 27, 2025, 02:55:49 PM

Do you have 300Bs in the tube sockets? 

If so, carefully measure the DC voltage between pins 1 and 4 on each 4 pin socket and report that back.

Title: Re: Voltage at terminals 25 and 30 BeePre
Post by: Yossihaimberg on February 28, 2025, 07:47:41 AM

A(1-4) 4.95 VDC

B(1-4) 4.98 VDC

Title: Re: Voltage at terminals 25 and 30 BeePre
Post by: Paul Birkeland on February 28, 2025, 10:39:49 AM

What DC voltages do you see at pin 2 on each 4 pin socket?

Title: Re: Voltage at terminals 25 and 30 BeePre
Post by: Yossihaimberg on February 28, 2025, 10:49:38 AM

Between pin 2 and which pin?

Title: Re: Voltage at terminals 25 and 30 BeePre
Post by: Paul Birkeland on February 28, 2025, 10:52:15 AM

Ground.

Title: Re: Voltage at terminals 25 and 30 BeePre
Post by: Yossihaimberg on February 28, 2025, 11:08:06 AM

A(2-ground)  103 VDC

B(2-ground)  103.4 VDC

Title: Re: Voltage at terminals 25 and 30 BeePre
Post by: Yossihaimberg on February 28, 2025, 01:43:30 PM

Problem solved!!

 I may have forgotten to insert the 30-0Bs before checking the voltage. The readings now are correct at 10VDC between 14 and 25 or 30.

Thanks again for your amazing support!