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Vintage Tape (Audio), Cassette, Wire and Magnetic Disc Recorders and Players Open-reel tape recorders, cassette recorders, 8-track players etc. |
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28th Apr 2017, 3:14 pm | #1 |
Heptode
Join Date: Feb 2011
Location: Southampton, Hampshire, UK.
Posts: 574
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Brenell Mk5 series 2 deck heads o/c?
I have this Brenell Mk5 series 2 deck, which I need to sell on behalf of three sisters, whose father was a BBC engineer and who has just died.
What is the best way, please, of checking the continuity in the heads with my Fluke without risking damaging them? Any help would be welcome. Thanks Dave |
28th Apr 2017, 6:02 pm | #2 |
Dekatron
Join Date: May 2008
Location: Derby, UK.
Posts: 7,735
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Re: Brenell Mk5 series 2 deck heads o/c?
Set the meter to a resistance range and apply the probes to the terminals.
The potential danger to tape heads with analogue meters was never burning out the coil (there is more power going through the heads during recording than any normal multimeter puts out), but magnetising the core. Which then leaves your precious tapes getting quieter with every listen ..... No prizes for guessing how I discovered this
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If I have seen further than others, it is because I was standing on a pile of failed experiments. |
29th Apr 2017, 9:49 am | #3 |
Octode
Join Date: Jul 2009
Location: Carmel, Llannerchymedd, Anglesey, UK.
Posts: 1,498
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Re: Brenell Mk5 series 2 deck heads o/c?
Even if you use AC to check head continuity, there is a danger of magnetising the core unless the signal can be initiated and removed slowly. In either case if you have access to a head de-magnetiser (basically a solenoid powered from 50c/s, which gives a strong field), this should clear the heads.
The method is to switch on the de-mag a foot or so away from the heads, bring it into close contact with the head for a few seconds, then slowly move it away before switching off. Be warned though, that the same instrument has the capability to erase tapes, so they should be well away! |
30th Apr 2017, 3:51 pm | #4 |
Octode
Join Date: May 2003
Location: Belper Derbyshire
Posts: 1,910
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Re: Brenell Mk5 series 2 deck heads o/c?
If you are worried about magnetising the head, could you put a 10k resistor in series with the head on a multimeter resistance range. The current flowing would be pretty much negliable.
Christopher Capener
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Interests in the collection and restoration of Tefifon players and 405 line television |
13th Jun 2017, 8:58 pm | #5 |
Heptode
Join Date: Feb 2011
Location: Southampton, Hampshire, UK.
Posts: 574
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Re: Brenell Mk5 series 2 deck heads o/c?
Hi Folks
All your answers make complete sense - I realise now, any current will magnetise the heads to a certain extent! Thanks very much. MODs please close - thanks Dave |
3rd Aug 2017, 10:14 am | #6 |
Heptode
Join Date: Feb 2011
Location: Southampton, Hampshire, UK.
Posts: 574
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Re: Brenell Mk5 series 2 deck heads o/c?
Hi folks
This tape deck and Brenell R2R recorder are now with Andy. Mods - please close. Thanks |