Homebrew Record Player. BSR UA6 deck and RS Components. Stereo Amplifier. - Page 4 - UK Vintage Radio Repair and Restoration Discussion Forum

Bigears · 24th Oct 2021, 5:37 pm

I have connected the screen cable the inner one to the top tag and the one " outer one copper braiding to the bottom tag ,
Powered up I get nothing from the speaker not even a hum, but when I sent in my OP I was making humming noise When I eventually get it working I will renew the mains lead with earth and replace the old TV aerial

Station X · 24th Oct 2021, 8:47 pm

See post #58. You need to reverse the coaxial cable so that the braid is connected to the lower terminal of the volume control.

While you have the cable disconnected carry out a buzz test as described in post #56.

Bigears · 25th Oct 2021, 11:52 am

OK will do Graham

Bigears · 25th Oct 2021, 9:31 pm

BSR UA6 made for Pye

Bigears · 25th Oct 2021, 9:32 pm

BSR made for Pye ?

Bigears · 25th Oct 2021, 10:32 pm

You mean hold the screw driver by the metal part, won't I get a shock ?

Station X · 25th Oct 2021, 10:35 pm

Unlikely. The amplifier operates at a low voltage, which isn't connected to the pickup leads in any case.

Audio1950 · 26th Oct 2021, 10:11 am

Quote:

Originally Posted by Bigears

BSR UA6 made for Pye

As Edward has said, the standard UA6, which was used for hundreds of different record players, was modified specially for the Pye Black Box. It had a metal arm, as opposed to the usual plastic one, and a raised "dome" at the rear with the "Pye" logo set into it.

Barry

Bigears · 26th Oct 2021, 11:20 am

Graham, I removed the two wires coming from the pick-up arm from the volume switch leaving the brown and blue connected and carried out the Screwdriver test which was negative, no sounds from speaker, also I have replaced the mains cable with a 3 core cable and earthed it to the chassis, and I am going to replace the TV cable as you suggest, but before I solder them I will send a picture of the wiring using test cables from the Red & Black cables from the picking arm going to the Switch. Regards Ken

Station X · 26th Oct 2021, 11:33 am

Please confirm that with power applied there is no sound from the speaker whatsoever ie no hum or hiss.

Bigears · 26th Oct 2021, 11:39 am

no sound what so ever

Bigears · 26th Oct 2021, 12:33 pm

Graham, here are the pictures of the wiring using test cables from the Red & Black cables from the picking arm going to the Switch. Regards Ken

Station X · 26th Oct 2021, 8:32 pm

I think we'd better find out why you're getting no sound from the speaker.

With mains power applied check that the turntable can be made to rotate under power. This will prove that the fuse in the mains plug is OK.

Then with power still applied measure the DC voltage on the wires coming from the smoothing capacitor.

Bigears · 27th Oct 2021, 9:08 am

Hi Graham, Turntable rotates ,DC voltage on the wires coming from the smoothing capacitor reads well it flashers between 8.13- 10.57 Ken

Station X · 27th Oct 2021, 9:37 am

I assume the reading is in volts? It should be steady, check for loose connections, shorting wires etc.

Trace the red and black? wires from the power supply area to the amplifier. what voltage do you see on the amplifier end of the leads? Is the polarity correct?

Bigears · 27th Oct 2021, 1:46 pm

OK I did the test again 7.90 volts thats with the red lead of the millimetre going to the red lead red lead of the smoothing capacitor and the black to the black

ms660 · 27th Oct 2021, 4:06 pm

If the IC is a SL402 or SL403 type then there's some more general info on them here, starting on mag. page 741 if it's any help:

https://worldradiohistory.com/UK/Pra...cs-1969-10.pdf

Lawrence.

peter_sol · 27th Oct 2021, 4:08 pm

I assume you had the volume control fully clockwise to do the hum test. That voltage is low for that IC but as it looks like a 6.3v transformer is being used its OK.

vidjoman · 27th Oct 2021, 4:13 pm

There looks to be 3 pins of the IC that are not soldered to the PCB. Shown in photo of solder side in post 41.
I get the impression some unknown person (probably a bodger) has tried to fault find in the past and gave up. I see no reason for the 'output' transformer as the IC can drive a speaker directly unless an odd impedance speaker has been fitted. The original circuit does not show a choke in the power supply either.

ms660 · 27th Oct 2021, 4:24 pm

Quote:

Originally Posted by vidjoman

There looks to be 3 pins of the IC that are not soldered to the PCB. Shown in photo of solder side in post 41.

Pins 7, 8 & 9 so far as I can make out.

Lawrence.

24th Oct 2021, 5:37 pm	#61
Bigears Pentode Join Date: Nov 2017 Location: Durham, County Durham, UK. Posts: 144	Re: Homebrew Record Player. BSR UA6 deck and RS Components. Stereo Amplifier. I have connected the screen cable the inner one to the top tag and the one " outer one copper braiding to the bottom tag , Powered up I get nothing from the speaker not even a hum, but when I sent in my OP I was making humming noise When I eventually get it working I will renew the mains lead with earth and replace the old TV aerial Attached Thumbnails Last edited by Bigears; 24th Oct 2021 at 5:47 pm.

24th Oct 2021, 8:47 pm	#62
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,288	Re: Homebrew Record Player. BSR UA6 deck and RS Components. Stereo Amplifier. See post #58. You need to reverse the coaxial cable so that the braid is connected to the lower terminal of the volume control. While you have the cable disconnected carry out a buzz test as described in post #56. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

25th Oct 2021, 11:52 am	#63
Bigears Pentode Join Date: Nov 2017 Location: Durham, County Durham, UK. Posts: 144	Re: Homebrew Record Player. BSR UA6 deck and RS Components. Stereo Amplifier. OK will do Graham

25th Oct 2021, 9:31 pm	#64
Bigears Pentode Join Date: Nov 2017 Location: Durham, County Durham, UK. Posts: 144	Re: MONARCH BSR Black Box BSR UA6 made for Pye Attached Thumbnails

25th Oct 2021, 9:32 pm	#65
Bigears Pentode Join Date: Nov 2017 Location: Durham, County Durham, UK. Posts: 144	Re: MONARCH BSR Black Box BSR made for Pye ?

25th Oct 2021, 10:32 pm	#66
Bigears Pentode Join Date: Nov 2017 Location: Durham, County Durham, UK. Posts: 144	Re: Homebrew Record Player. BSR UA6 deck and RS Components. Stereo Amplifier. You mean hold the screw driver by the metal part, won't I get a shock ?

25th Oct 2021, 10:35 pm	#67
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,288	Re: Homebrew Record Player. BSR UA6 deck and RS Components. Stereo Amplifier. Unlikely. The amplifier operates at a low voltage, which isn't connected to the pickup leads in any case. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

26th Oct 2021, 11:20 am	#69
Bigears Pentode Join Date: Nov 2017 Location: Durham, County Durham, UK. Posts: 144	Re: Homebrew Record Player. BSR UA6 deck and RS Components. Stereo Amplifier. Graham, I removed the two wires coming from the pick-up arm from the volume switch leaving the brown and blue connected and carried out the Screwdriver test which was negative, no sounds from speaker, also I have replaced the mains cable with a 3 core cable and earthed it to the chassis, and I am going to replace the TV cable as you suggest, but before I solder them I will send a picture of the wiring using test cables from the Red & Black cables from the picking arm going to the Switch. Regards Ken

26th Oct 2021, 11:33 am	#70
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,288	Re: Homebrew Record Player. BSR UA6 deck and RS Components. Stereo Amplifier. Please confirm that with power applied there is no sound from the speaker whatsoever ie no hum or hiss. __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

26th Oct 2021, 11:39 am	#71
Bigears Pentode Join Date: Nov 2017 Location: Durham, County Durham, UK. Posts: 144	Re: Homebrew Record Player. BSR UA6 deck and RS Components. Stereo Amplifier. no sound what so ever

26th Oct 2021, 12:33 pm	#72
Bigears Pentode Join Date: Nov 2017 Location: Durham, County Durham, UK. Posts: 144	Re: Homebrew Record Player. BSR UA6 deck and RS Components. Stereo Amplifier. Graham, here are the pictures of the wiring using test cables from the Red & Black cables from the picking arm going to the Switch. Regards Ken Attached Thumbnails

26th Oct 2021, 8:32 pm	#73
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,288	Re: Homebrew Record Player. BSR UA6 deck and RS Components. Stereo Amplifier. I think we'd better find out why you're getting no sound from the speaker. With mains power applied check that the turntable can be made to rotate under power. This will prove that the fuse in the mains plug is OK. Then with power still applied measure the DC voltage on the wires coming from the smoothing capacitor. Attached Thumbnails __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

27th Oct 2021, 9:08 am	#74
Bigears Pentode Join Date: Nov 2017 Location: Durham, County Durham, UK. Posts: 144	Re: Homebrew Record Player. BSR UA6 deck and RS Components. Stereo Amplifier. Hi Graham, Turntable rotates ,DC voltage on the wires coming from the smoothing capacitor reads well it flashers between 8.13- 10.57 Ken Last edited by Bigears; 27th Oct 2021 at 9:13 am.

27th Oct 2021, 9:37 am	#75
Station X Moderator Join Date: Jan 2003 Location: Ipswich, Suffolk, IP4, UK. Posts: 21,288	Re: Homebrew Record Player. BSR UA6 deck and RS Components. Stereo Amplifier. I assume the reading is in volts? It should be steady, check for loose connections, shorting wires etc. Trace the red and black? wires from the power supply area to the amplifier. what voltage do you see on the amplifier end of the leads? Is the polarity correct? __________________ Graham. Forum Moderator Reach for your meter before you reach for your soldering iron.

27th Oct 2021, 1:46 pm	#76
Bigears Pentode Join Date: Nov 2017 Location: Durham, County Durham, UK. Posts: 144	Re: Homebrew Record Player. BSR UA6 deck and RS Components. Stereo Amplifier. OK I did the test again 7.90 volts thats with the red lead of the millimetre going to the red lead red lead of the smoothing capacitor and the black to the black Last edited by Bigears; 27th Oct 2021 at 1:57 pm.

27th Oct 2021, 4:06 pm	#77
ms660 Dekatron Join Date: Apr 2011 Location: Cornwall, UK. Posts: 13,454	Re: Homebrew Record Player. BSR UA6 deck and RS Components. Stereo Amplifier. If the IC is a SL402 or SL403 type then there's some more general info on them here, starting on mag. page 741 if it's any help: https://worldradiohistory.com/UK/Pra...cs-1969-10.pdf Lawrence.

27th Oct 2021, 4:08 pm	#78
peter_sol Octode Join Date: Aug 2003 Location: Welwyn Garden City, Herts. UK. Posts: 1,906	Re: Homebrew Record Player. BSR UA6 deck and RS Components. Stereo Amplifier. I assume you had the volume control fully clockwise to do the hum test. That voltage is low for that IC but as it looks like a 6.3v transformer is being used its OK.

27th Oct 2021, 4:13 pm	#79
vidjoman Dekatron Join Date: Jun 2013 Location: East Sussex, UK. Posts: 3,326	Re: Homebrew Record Player. BSR UA6 deck and RS Components. Stereo Amplifier. There looks to be 3 pins of the IC that are not soldered to the PCB. Shown in photo of solder side in post 41. I get the impression some unknown person (probably a bodger) has tried to fault find in the past and gave up. I see no reason for the 'output' transformer as the IC can drive a speaker directly unless an odd impedance speaker has been fitted. The original circuit does not show a choke in the power supply either.