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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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Old 13th Apr 2018, 2:38 pm   #1
Quadman
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Default Tape Head Open Circuit

After the kind help recently on this group to identify my 1960 Countess tape recorder I have found a significant problem to my restoration in that the replay head is unfortunately open circuit. Temporarily wiring the record head into the replay amplifier has confirmed this and a pre-recorded test tape plays albeit at low volume presumably because of the head impedance mismatch. Does anyone know of a source for a suitable replacement 2 track mono replay head as shown in the attached picture? I also will need a replacement capstan drive flat belt (or material to make one). I have shortened the original "rubber" belt which is 7mm x 1mm section and at present the tape transport is operational.

Any help or useful suggestions welcome.

Paul
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Old 13th Apr 2018, 4:42 pm   #2
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Smile Re: Tape Head Open Circuit

Hi,
Your machine has three heads. Could not the 'other' head be pressed into service, at least temporarily? It's more than likely of the same characteristics.
Just a thought.
Cheers, Pete.
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Old 13th Apr 2018, 6:43 pm   #3
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Default Re: Tape Head Open Circuit

Hi Pete

I have done this as a test but this is a far from an ideal solution as the record head has different characteristics/impedance and it would need complicated switching to work in both record and playback modes which is not really practical on this compact model. Also the advantage of off-tape monitoring whilst recording would be lost. Failing finding the correct replacement it is more likely that a similar sized head from a different machine could be pressed into service with some mechanical modifications. I will explore this option if all else fails.

Thank you for your input....kind regards

Paul
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Old 14th Apr 2018, 6:46 am   #4
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Default Re: Tape Head Open Circuit

I found an o/c head on a Ferrograph, turned out to be a broken solder connection. if you can dismantle yours it might be the same.
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Old 14th Apr 2018, 9:38 am   #5
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Default Re: Tape Head Open Circuit

Thank you Richard unfortunately these heads are "potted" with the lead disappearing into the assembly with no access to its termination. it might be possible to carefullycut it open but failure is highly likely so I really need to find an alternative replacement before going do this route and finishing up with potential bin fodder.

Paul
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Old 16th Apr 2018, 12:12 pm   #6
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Default Re: Tape Head Open Circuit

I don't really recognize the logo but the style of the heads look like early Bogen, if so, then open circuit windings are fairly common (and not possible to do much about).

Using the record head for playback is more or less doomed from the outset as the gap will be wider hampering frequency response, not to mention the windings being different.

On the brighter side, finding an identical replacement may not be critical, as long as the head is designed for the same type of amplifier (i.e. transistor or valve). Since the head is essentially mounted on a small brass plate, it would not be too difficult to replace with something else and make it fit without too much hassle. If nothing else it might make the machine operational while a more suitable replacement is being sought.
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Old 16th Apr 2018, 12:32 pm   #7
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Default Re: Tape Head Open Circuit

The stylised W makes me think Woelke?
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Old 16th Apr 2018, 2:05 pm   #8
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Default Re: Tape Head Open Circuit

I don't recognize them as such, but comparing the logo to the one in the ad on this page you may be right:

http://www.magnetbandmuseum.info/woelke-muenchen.html

(the one in the ad is more angular but could simply be a 1960s rather than 1950s update).
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Old 16th Apr 2018, 2:16 pm   #9
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Default Re: Tape Head Open Circuit

It could also be the Miniflux logo. These do tend to go o/c for no reason, much like Bogen.

They were used in a variety of decks, such as Truvox. You might be able to find something suitable on a scrap deck from one of the other manufacturers that used them.

All I could find was a compliments slip, sorry. The logo is embossed in the paper so not easy to reproduce.

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Old 16th Apr 2018, 2:32 pm   #10
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Default Re: Tape Head Open Circuit

Looks like Woelke and Miniflux are one and the same:

https://www.radiomuseum.org/dsp_hers...ompany_id=7356

One way up the logo's a 'W', the other way up it's an 'M'
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Old 16th Apr 2018, 3:33 pm   #11
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Default Re: Tape Head Open Circuit

Thank you guys for your comments and help, all very useful and appreciated. You seem to have tracked the manufacture down and the more I look at the head the more I think that a repair to the existing head is a hopeless task. However it is easily removable and a different high impedance valve type head on a suitable adapter plate is a strong possibility. Luckily I have access to a well equipped workshop and as a model engineer can do such things. I will keep a lookout for a suitable replacement at this seasons rallies.

Kind regards all

Paul
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Old 16th Apr 2018, 4:01 pm   #12
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Default Re: Tape Head Open Circuit

You could try Greg Orton in Cleveland US. He is a one man band tape head refurbish/remanufacturer at Flux Magnetics..

http://website.informer.com/visit?do...xmagnetics.com
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Old 16th Apr 2018, 9:32 pm   #13
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Default Re: Tape Head Open Circuit

Well if my recorder was a high class professional studio model (which it certainly is not) then Greg Orton might be a solution but I fear that that route would only prove that the refurbishment would be beyond economic repair. Thank you for the suggestion but my Yorkshire blood stops me going down such aa expensive route.

Paul
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Old 17th Apr 2018, 11:24 am   #14
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Default Re: Tape Head Open Circuit

Oh well - but I find US based services ready to accept 'a challenge' so to speak,
and thus it may not be as expensive as you might imagine- after all you can only ask and an Email costs you nothing..never mind.
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Old 17th Apr 2018, 11:40 am   #15
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Default Re: Tape Head Open Circuit

I think I have one of these machines.
I *know* I have several tape heads removed (by others) from machines of a similar era.
How about if I open up my machine (my aging muscles permitting) and then see if any of my miscellaneous heads look to be in any way compatible? You'd probably have to make your own adaptor plate.
If all the above happens, it's yours for the asking.
Graham
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Old 17th Apr 2018, 4:26 pm   #16
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Default Re: Tape Head Open Circuit

Hi Graham

Thank you for your kind offer. Obviously if you find that you have an identical head or even a 1/4" tape two track head suitable for a valve amplifier and of a size that will fit I would be very interested indeed and would gladly buy it from you. Making an adapter plate is no real problem as long as the head is of a suitable size. The spare heads that I have here are unfortunately all for cassette tape recorders and solid state amplifiers.

Let me know if you find anything in your collection. Kind regards

Paul
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Old 17th Apr 2018, 6:57 pm   #17
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Default Re: Tape Head Open Circuit

Hi Paul,
Just looked at my machine (no name on it as far as I can see) and had a look at the playback head. I'd say it's a little smaller than a typical "sugar cube" head from that era. With that in mind I've taken a couple of heads from their mounting plates - one seems to be a typical sugar cube, the other a little smaller from a front view but slightly deeper. These two seem to have less wear than other similar ones in my collection.
I measured their resistance using a DMM and a 10k series resistor and they both come out around 400 Ohms. They're certainly valve era heads so worth a try I reckon. Maybe you can hold them up against the passing tape before spending time properly mounting them.
PM me your postal address and I'll get them in the post in the next couple of days.
Graham
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Old 23rd Apr 2018, 3:28 pm   #18
Quadman
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Default Re: Tape Head Open Circuit

Hi Guys

Well Graham has very kindly sent me a couple of heads one of which has fitted nicely into the existing space and after a fair bit of work changing defunct capacitors in the amplifier the machine is up and working. The capstan drive belt is slipping so I need to replace this but all in all the machine should now live again. Thank you guys for all of your help with a special thank you to Graham.

Kind regards to all

Paul

PS Graham please send me you details so that I can reimburse you for your effort on my behalf.
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Old 26th Apr 2018, 5:17 am   #19
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Default Re: Tape Head Open Circuit

Though the attached is sadly now unavailable, the data may assist you
in seeking an appropriate replacement. The data is from Nortronics.

I was in the tape recorder repair business then.
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Old 27th Apr 2018, 3:10 pm   #20
Quadman
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Default Re: Tape Head Open Circuit

Hi Steve

Thanks for the info....all useful stuff

Cheers

Paul
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