Mute SUGDEN T48 - Schematic needed - UK Vintage Radio Repair and Restoration Discussion Forum

vaslejean · 20th Jul 2019, 2:45 pm

Would anyone be able to provide a "legible" schematic for the Sugden T48 tuner ? I believe the schematic was a part of the original owner manual

The schematic as offered on the manufacturer page is rather difficult to read.

I have an old tuner of that model that was apparently imported or brought to Canada while originally intended for the British market as per the station indicators. (BBC1 ...BBC2.. et cetera...)

The din plug output connector have been replaced by RCA connectors.

I have been able to confirm of the presence of dc which suggest it would have been appropriately converted for 120 A/C operation .

As mentioned, I have D/C on the power supply capacitors and also on the six tuning presets that serves to "lock" the desired stations - But no output at all...

I have yet to verify the voltage present at IC2 (CA1310E stereo MPX stage) as it drives the transistors at the output .

Any assistance will be appreciated.

Nuvistor · 20th Jul 2019, 2:54 pm

Have to tried Sugden?
https://www.sugdenaudio.com/contact

vaslejean · 20th Jul 2019, 4:10 pm

Thank you Frank.

I have contacted Sugden in the past and was somehow hopping some members of this forum could have this same tuner and possibly have the literature on hand or scanned.

Sugden have been friendly and helpful anytime I had to contact them, but I just don't feel like bugging them for a 45 year's old tuner. Again, they have the schematic online (part of the owner manual in PDF), but it is difficult to read .

For the time being I will go on with the data I have on the CA1310E & CA3089 IC and check if any of the voltages I found make sens.

Thank you again.

Humber888 · 20th Jul 2019, 4:59 pm

I've got a T48 (may be MK2) boxed in the loft somewhere. So it should have the instructions with it. Give me a day or two to boldly go where mere mortals fear to tread!

Mike

vaslejean · 20th Jul 2019, 9:29 pm

Thank you mike ...

You will oblige me , but dont expose yourself to extreme danger for it's just an old fm tuner ...

... I have measured 3.4 volt dc supply on the MPX IC. (10 volts would be more likely to be found there I would think) I will most possibly have to dismantle what Carol Gibson has put together to investigate further in it. As many product of that brand, manufactured at that time, the name of one of the assembly people was left on a sticker inside the thing.

Michel

Nuvistor · 20th Jul 2019, 9:52 pm

I had some Sugden test gear in the 70’s, audio test set, worked very well for its price. Three items audio osc, AC milli volt meter and forget what it was called but it nulled out the fundamental and I was able to read the total harmonic content that was left.

Humber888 · 21st Jul 2019, 2:26 pm

I found the T48 in its original box in the loft - never been used apart from a quick test as its colour scheme did not match the A48 I had. Inside I found the instructions for … an A48 amplifier! I them had a search in another place where the T48 instructions might have been saved and found them. So I have scanned the instructions to a PDF file (2.35MB) and I will email the file to you if you send me a PM with your email details (the PM system does not allow attachments).

Cheers

Mike

vaslejean · 21st Jul 2019, 2:58 pm

...PM sent ,

Thank you Mike.

Michel

Humber888 · 21st Jul 2019, 3:23 pm

Michel, your details received and email sent.

Mike

20th Jul 2019, 2:45 pm	#1
vaslejean Tetrode Join Date: Jul 2006 Location: Montréal, Canada. Posts: 78	Mute SUGDEN T48 - Schematic needed Would anyone be able to provide a "legible" schematic for the Sugden T48 tuner ? I believe the schematic was a part of the original owner manual The schematic as offered on the manufacturer page is rather difficult to read. I have an old tuner of that model that was apparently imported or brought to Canada while originally intended for the British market as per the station indicators. (BBC1 ...BBC2.. et cetera...) The din plug output connector have been replaced by RCA connectors. I have been able to confirm of the presence of dc which suggest it would have been appropriately converted for 120 A/C operation . As mentioned, I have D/C on the power supply capacitors and also on the six tuning presets that serves to "lock" the desired stations - But no output at all... I have yet to verify the voltage present at IC2 (CA1310E stereo MPX stage) as it drives the transistors at the output . Any assistance will be appreciated.

20th Jul 2019, 2:54 pm	#2
Nuvistor Dekatron Join Date: Aug 2013 Location: Wigan, Greater Manchester, UK. Posts: 9,431	Re: Mute SUGDEN T48 - Schematic needed Have to tried Sugden? https://www.sugdenaudio.com/contact __________________ Frank

20th Jul 2019, 4:10 pm	#3
vaslejean Tetrode Join Date: Jul 2006 Location: Montréal, Canada. Posts: 78	Re: Mute SUGDEN T48 - Schematic needed Thank you Frank. I have contacted Sugden in the past and was somehow hopping some members of this forum could have this same tuner and possibly have the literature on hand or scanned. Sugden have been friendly and helpful anytime I had to contact them, but I just don't feel like bugging them for a 45 year's old tuner. Again, they have the schematic online (part of the owner manual in PDF), but it is difficult to read . For the time being I will go on with the data I have on the CA1310E & CA3089 IC and check if any of the voltages I found make sens. Thank you again.

20th Jul 2019, 4:59 pm	#4
Humber888 Heptode Join Date: Jul 2012 Location: Bromley, London, UK. Posts: 702	Re: Mute SUGDEN T48 - Schematic needed I've got a T48 (may be MK2) boxed in the loft somewhere. So it should have the instructions with it. Give me a day or two to boldly go where mere mortals fear to tread! Mike

20th Jul 2019, 9:29 pm	#5
vaslejean Tetrode Join Date: Jul 2006 Location: Montréal, Canada. Posts: 78	Re: Mute SUGDEN T48 - Schematic needed Thank you mike ... You will oblige me , but dont expose yourself to extreme danger for it's just an old fm tuner ... ... I have measured 3.4 volt dc supply on the MPX IC. (10 volts would be more likely to be found there I would think) I will most possibly have to dismantle what Carol Gibson has put together to investigate further in it. As many product of that brand, manufactured at that time, the name of one of the assembly people was left on a sticker inside the thing. Michel

20th Jul 2019, 9:52 pm	#6
Nuvistor Dekatron Join Date: Aug 2013 Location: Wigan, Greater Manchester, UK. Posts: 9,431	Re: Mute SUGDEN T48 - Schematic needed I had some Sugden test gear in the 70’s, audio test set, worked very well for its price. Three items audio osc, AC milli volt meter and forget what it was called but it nulled out the fundamental and I was able to read the total harmonic content that was left. __________________ Frank

21st Jul 2019, 2:26 pm	#7
Humber888 Heptode Join Date: Jul 2012 Location: Bromley, London, UK. Posts: 702	Re: Mute SUGDEN T48 - Schematic needed I found the T48 in its original box in the loft - never been used apart from a quick test as its colour scheme did not match the A48 I had. Inside I found the instructions for … an A48 amplifier! I them had a search in another place where the T48 instructions might have been saved and found them. So I have scanned the instructions to a PDF file (2.35MB) and I will email the file to you if you send me a PM with your email details (the PM system does not allow attachments). Cheers Mike

21st Jul 2019, 2:58 pm	#8
vaslejean Tetrode Join Date: Jul 2006 Location: Montréal, Canada. Posts: 78	Re: Mute SUGDEN T48 - Schematic needed ...PM sent , Thank you Mike. Michel

21st Jul 2019, 3:23 pm	#9
Humber888 Heptode Join Date: Jul 2012 Location: Bromley, London, UK. Posts: 702	Re: Mute SUGDEN T48 - Schematic needed Michel, your details received and email sent. Mike