Sound Belle reel-to-reel heads - UK Vintage Radio Repair and Restoration Discussion Forum

jmcilkley · 17th Oct 2020, 8:41 am

I have an old Sounds Belle tape recorder - a very neat design from the late 50s - but it unfortunately doesn't produce any sound. There is a button labelled P.A. (I guess for Public Address) which connects the microphone input straight through to the amplifier section and to the loudspeaker, and this works fine.
But nothing at all from the tape, so I suspect the play/record head may not be working. I don't have a signal injector but I managed to wire up an old ceramic record player cartridge to the wires to the tape head (as I believe the signal levels are similar) and miraculously this worked.
The tape player is only mono, of course, but the tape head has 4 connectors. Two of these are soldered together and the other two carry the signal. I'm wondering if the other two connectors are for a second channel and if I use those 2 connectors and short out the ones that are currently used, maybe this might work? Any suggestions? Or any ideas where I might find a replacement head at a price that would make this worth repairing?

barrymagrec · 17th Oct 2020, 1:34 pm

Tape heads have two coils which are normally connected in series. Sometimes this connection is external, as appears to be the case here.

A crystal cartridge gives several times the output level of a tape head so your replay amplifier may be low gain, equally the head may be faulty. If you have a multimeter check it for DC resistance, assuming there is a reading (out of circuit) the head is probably O.K.

Ideally you should demagnetise the head after passing DC through it but at this stage don`t worry.

I assume you don`t have a tape with a known recording on it to try.

Edward Huggins · 17th Oct 2020, 1:55 pm

There is scant information about this recorder as the tape-deck manufacturer may need some researching. To help your searches, your machine is a SOUND "Belle" (not Sounds) made by Tape Recorders (Electronics ) Limited. I have the original 1959 sales brochure for this rare model - but not readily accessible at this time.

Herald1360 · 17th Oct 2020, 2:11 pm

The service info is up top:

At any rate for serial 35000 up. Apparently earlier version had ECC83 instead of EF86 front end.

https://www.service-data.com/section.php/7622/1/a15935

It's actually a Sound Belle according to the service sheet.

jmcilkley · 17th Oct 2020, 3:08 pm

I have found a circuit diagram: https://www.service-data.com/section.php/7622/1/a15935. It's a bit hard to follow but seems accurate. I do have a tape but I don't know if there is anything on it. I tried recording on it from the microphone and playing it back, but nothing. Whether it is not recording or just not playing back - or maybe both - I don't know. I was wondering about making a coil with the lead from a jack plug and bringing it close to the head. Would this work? Would it work the other way around to check the recording?
I can't find any replacement heads on ebay unfortunately.

DMcMahon · 17th Oct 2020, 3:17 pm

I was reading that the Sound Belle does not use capstan drive, that is fairly unusual, I guess it uses a form of rim drive ?

DMcMahon · 17th Oct 2020, 3:23 pm

Have you checked the heads for continuity readings as advised above ?

If you had access to another recorder (working) you could check if the tape you have has any existing recordings on it and if the new recording attempts are actually being recorded to the tape.

Ted Kendall · 17th Oct 2020, 6:23 pm

I think this is a badged Incis (Italian), as were many budget machines of the 1960s.

jmcilkley · 17th Oct 2020, 6:38 pm

Yes, it has a rim drive and although the motor is really quiet the drive to the spool via the rim is very noisy so I will have to dismantle that.
Unfortunately I don't jave another tape recorder so need to fimd other ways of testing.

Paul_RK · 17th Oct 2020, 7:23 pm

Quote:

Originally Posted by Ted Kendall

I think this is a badged Incis (Italian)...

I've a couple of Sound Belles here, one with brown mouldings and the other, later I think, in a dove grey, and haven't suspected that. Just took the covers off one to have a look, it's hard to be confident about the nationality of the deck mechanism, but components are primarily British: capacitors from our old friends Hunts, Erie, Dubilier and Daly with a couple from ERO, SenTerCel metal rectifier, Mullard valves, Bulgin mains socket. The Daly electrolytics in particular are almost certain to be misbehaving seriously after 60-odd years (motor on this machine is dated 14.10.59).

Paul

jmcilkley · 18th Oct 2020, 9:39 am

Presumably without a capstan the tape speed will vary as the diameter of tape on the right hand spool changes. This would make it impossible to play a tape from another machine that did use a capstan for constant tape speed. An unusual design!
Checking the signal at the record/playback head, when set to record it looks fine with the bias at about 47kHz. Similarly the erase head shows the right signal. So it seems that the tape recorder is certainly working as far as the r/p head. The tape head does show a reasonable resistance of about 230 ohms so I think I now have to find a way of sending a magnetic signal through the head to see if that gets through or finding a bit of tape that I'm sure has something on.
My model also has Daly and ERO capacitors so it sounds like the same model and probably UK made. Surprisingly, the capacitors test out as still withing spec but I will be replacing them once I can sort out the R/P head.
Apologies if I seem a bit clueless but this is the first time I've worked on a tape recorder. Record players and amplifiers have been more my thing up to now but this seemed like a challenge.

DMcMahon · 18th Oct 2020, 9:49 am

Are you measuring the Record Bias/Erase signals using an oscilloscope ? If you have a scope then you could monitor the record signal and make sure it is getting through to the head.

At the head itself the record audio signal is modulated onto the much larger record bias signal so can be difficult to see. Similarly when replaying a tape (that has a recording on) you can monitor the playback signal.

David

jmcilkley · 18th Oct 2020, 10:13 am

Yes. On the scope I can see the bias signal and with the microphone connected I can see the overlayed voice frequency. So all seems to be fine recording and previously I injected a signal there from a ceramic cartridge and that played fine. So from the R/P head back through the recorder it all seems to work fine but when I try to record onto the tape and then play it back I get nothing at all.

Refugee · 18th Oct 2020, 10:57 am

It sounds like it has got a very dirty head.

Paul_RK · 18th Oct 2020, 6:55 pm

Quote:

Originally Posted by jmcilkley

This would make it impossible to play a tape from another machine that did use a capstan for constant tape speed...

Well, not impossible assuming the head orientation is more or less as standard, but it would only be at roughly the right speed for a little while at best

As I recall I became aware of the model somewhere around 1970 by way of an advertisement (Exchange and Mart perhaps) from somebody desperately seeking such a machine on which to play some old tapes that had been recorded on one. The two I have must have turned up at auction and/or flea market about 20 years after that, and seemed worth giving a home to for their oddity, but I've still not tried to get either of them running. The motor is a Papst outer-rotor type which looks very like those used in Grundig recorders of the period.

jmcilkley · 18th Oct 2020, 7:03 pm

Thanks for the interesting information, Paul. Do you happen to know why 2 of the connections on the head are just connected together?

DMcMahon · 18th Oct 2020, 7:50 pm

Ensure that the tape has not been wound on back to front.

Paul_RK · 18th Oct 2020, 7:52 pm

Quote:

Originally Posted by jmcilkley

Do you happen to know why 2 of the connections on the head are just connected together?

Just a ground connection common to record and playback, unless I'm wrong which especially in tape recorder matters is very likely! Here are a couple of photos of the head block of mine in case they help someone recognise the heads or diagnose what the problem may be.

barrymagrec · 18th Oct 2020, 8:08 pm

Quote:

Originally Posted by jmcilkley

Thanks for the interesting information, Paul. Do you happen to know why 2 of the connections on the head are just connected together?

Like I said in post 2.

TIMTAPE · 18th Oct 2020, 8:12 pm

The tape needs to be in intimate contact with the head face. Is the felt pad in good condition to make this happen?

17th Oct 2020, 8:41 am	#1
jmcilkley Triode Join Date: Jan 2020 Location: Ilkley, West Yorkshire, UK. Posts: 28	Sound Belle reel-to-reel heads I have an old Sounds Belle tape recorder - a very neat design from the late 50s - but it unfortunately doesn't produce any sound. There is a button labelled P.A. (I guess for Public Address) which connects the microphone input straight through to the amplifier section and to the loudspeaker, and this works fine. But nothing at all from the tape, so I suspect the play/record head may not be working. I don't have a signal injector but I managed to wire up an old ceramic record player cartridge to the wires to the tape head (as I believe the signal levels are similar) and miraculously this worked. The tape player is only mono, of course, but the tape head has 4 connectors. Two of these are soldered together and the other two carry the signal. I'm wondering if the other two connectors are for a second channel and if I use those 2 connectors and short out the ones that are currently used, maybe this might work? Any suggestions? Or any ideas where I might find a replacement head at a price that would make this worth repairing?

17th Oct 2020, 1:34 pm	#2
barrymagrec Heptode Join Date: Dec 2017 Location: Morden, Surrey, UK. Posts: 982	Re: Sounds Belle reel-to-reel heads Tape heads have two coils which are normally connected in series. Sometimes this connection is external, as appears to be the case here. A crystal cartridge gives several times the output level of a tape head so your replay amplifier may be low gain, equally the head may be faulty. If you have a multimeter check it for DC resistance, assuming there is a reading (out of circuit) the head is probably O.K. Ideally you should demagnetise the head after passing DC through it but at this stage don`t worry. I assume you don`t have a tape with a known recording on it to try.

17th Oct 2020, 1:55 pm	#3
Edward Huggins Dekatron Join Date: Sep 2015 Location: Southwold, Suffolk, UK. Posts: 6,276	Re: Sounds Belle reel-to-reel heads There is scant information about this recorder as the tape-deck manufacturer may need some researching. To help your searches, your machine is a SOUND "Belle" (not Sounds) made by Tape Recorders (Electronics ) Limited. I have the original 1959 sales brochure for this rare model - but not readily accessible at this time. __________________ Edward.

17th Oct 2020, 2:11 pm	#4
Herald1360 Dekatron Join Date: Feb 2007 Location: Leominster, Herefordshire, UK. Posts: 14,982	Re: Sounds Belle reel-to-reel heads The service info is up top: At any rate for serial 35000 up. Apparently earlier version had ECC83 instead of EF86 front end. https://www.service-data.com/section.php/7622/1/a15935 It's actually a Sound Belle according to the service sheet. __________________ ....__________ ....\|____\|\|__\|__\_____ .=.\| _---\__\|__\|_---_\|. .........O..Chris....O

17th Oct 2020, 3:08 pm	#5
jmcilkley Triode Join Date: Jan 2020 Location: Ilkley, West Yorkshire, UK. Posts: 28	Re: Sound Belle reel-to-reel heads I have found a circuit diagram: https://www.service-data.com/section.php/7622/1/a15935. It's a bit hard to follow but seems accurate. I do have a tape but I don't know if there is anything on it. I tried recording on it from the microphone and playing it back, but nothing. Whether it is not recording or just not playing back - or maybe both - I don't know. I was wondering about making a coil with the lead from a jack plug and bringing it close to the head. Would this work? Would it work the other way around to check the recording? I can't find any replacement heads on ebay unfortunately. Last edited by AC/HL; 17th Oct 2020 at 6:24 pm. Reason: Forum rules

17th Oct 2020, 3:17 pm	#6
DMcMahon Nonode Join Date: Apr 2019 Location: Worthing, West Sussex, UK. Posts: 2,683	Re: Sound Belle reel-to-reel heads I was reading that the Sound Belle does not use capstan drive, that is fairly unusual, I guess it uses a form of rim drive ?

17th Oct 2020, 3:23 pm	#7
DMcMahon Nonode Join Date: Apr 2019 Location: Worthing, West Sussex, UK. Posts: 2,683	Re: Sound Belle reel-to-reel heads Have you checked the heads for continuity readings as advised above ? If you had access to another recorder (working) you could check if the tape you have has any existing recordings on it and if the new recording attempts are actually being recorded to the tape.

17th Oct 2020, 6:23 pm	#8
Ted Kendall Nonode Join Date: Jul 2008 Location: Kington, Herefordshire, UK. Posts: 2,463	Re: Sound Belle reel-to-reel heads I think this is a badged Incis (Italian), as were many budget machines of the 1960s.

17th Oct 2020, 6:38 pm	#9
jmcilkley Triode Join Date: Jan 2020 Location: Ilkley, West Yorkshire, UK. Posts: 28	Re: Sound Belle reel-to-reel heads Yes, it has a rim drive and although the motor is really quiet the drive to the spool via the rim is very noisy so I will have to dismantle that. Unfortunately I don't jave another tape recorder so need to fimd other ways of testing. Last edited by jmcilkley; 17th Oct 2020 at 6:49 pm.

18th Oct 2020, 9:39 am	#11
jmcilkley Triode Join Date: Jan 2020 Location: Ilkley, West Yorkshire, UK. Posts: 28	Re: Sound Belle reel-to-reel heads Presumably without a capstan the tape speed will vary as the diameter of tape on the right hand spool changes. This would make it impossible to play a tape from another machine that did use a capstan for constant tape speed. An unusual design! Checking the signal at the record/playback head, when set to record it looks fine with the bias at about 47kHz. Similarly the erase head shows the right signal. So it seems that the tape recorder is certainly working as far as the r/p head. The tape head does show a reasonable resistance of about 230 ohms so I think I now have to find a way of sending a magnetic signal through the head to see if that gets through or finding a bit of tape that I'm sure has something on. My model also has Daly and ERO capacitors so it sounds like the same model and probably UK made. Surprisingly, the capacitors test out as still withing spec but I will be replacing them once I can sort out the R/P head. Apologies if I seem a bit clueless but this is the first time I've worked on a tape recorder. Record players and amplifiers have been more my thing up to now but this seemed like a challenge.

18th Oct 2020, 9:49 am	#12
DMcMahon Nonode Join Date: Apr 2019 Location: Worthing, West Sussex, UK. Posts: 2,683	Re: Sound Belle reel-to-reel heads Are you measuring the Record Bias/Erase signals using an oscilloscope ? If you have a scope then you could monitor the record signal and make sure it is getting through to the head. At the head itself the record audio signal is modulated onto the much larger record bias signal so can be difficult to see. Similarly when replaying a tape (that has a recording on) you can monitor the playback signal. David

18th Oct 2020, 10:13 am	#13
jmcilkley Triode Join Date: Jan 2020 Location: Ilkley, West Yorkshire, UK. Posts: 28	Re: Sound Belle reel-to-reel heads Yes. On the scope I can see the bias signal and with the microphone connected I can see the overlayed voice frequency. So all seems to be fine recording and previously I injected a signal there from a ceramic cartridge and that played fine. So from the R/P head back through the recorder it all seems to work fine but when I try to record onto the tape and then play it back I get nothing at all.

18th Oct 2020, 10:57 am	#14
Refugee Dekatron Join Date: Apr 2012 Location: Worksop, Nottinghamshire, UK. Posts: 4,833	Re: Sound Belle reel-to-reel heads It sounds like it has got a very dirty head.

18th Oct 2020, 7:03 pm	#16
jmcilkley Triode Join Date: Jan 2020 Location: Ilkley, West Yorkshire, UK. Posts: 28	Re: Sound Belle reel-to-reel heads Thanks for the interesting information, Paul. Do you happen to know why 2 of the connections on the head are just connected together?

18th Oct 2020, 7:50 pm	#17
DMcMahon Nonode Join Date: Apr 2019 Location: Worthing, West Sussex, UK. Posts: 2,683	Re: Sound Belle reel-to-reel heads Ensure that the tape has not been wound on back to front.

18th Oct 2020, 8:12 pm	#20
TIMTAPE Octode Join Date: Jul 2006 Location: Perth, Western Australia Posts: 1,386	Re: Sound Belle reel-to-reel heads The tape needs to be in intimate contact with the head face. Is the felt pad in good condition to make this happen?