Bush TP79 cassette

[Martin Bush]

Hello all

I've just picked up a Bush TP79 cassette player for the princely sum of £2.

While I am no fan of cassettes usually, I am a Bush fanatic, so I had to have this one.

Does anyone know where I would get the service data (seems not to be up top) and where I might get belts for it (I am presuming they will need sorting.

In truth I am hoping there's not much up with this as I don't feel up to trying to work on something so complex (by my standards).

Martin

[camtechman]

http://**********************/Schemati...=Xref&page=714

[Martin Bush]

That's great, thanks.

[Martin Bush]

Hello again all

I have got service data for this machine now (yes, I know there's a big gap between the last post and this!) but the only extract I have been able to get my hands on does not include information on the belts.

I've not opened the machine up yet but I presume the belts will need changing (after so long surely they will be in a somewhat suspect state).

What's the best way to go about souring belts? I see that on ebay and BangGood etc there's various multi-size selections - is that they way to go or is it better to measure up the exiting belts (presuming that they are up to it) and getting specific sizes?

If, and it is an if, this one goes OK then I may pick up more small machines to play with, so a batch of belts would not necessarily be a waste.

Martin

[paulsherwin]

Buy a bag of assorted generic belts, e.g. https://www.ebay.co.uk/itm/Mix-Casse...EAAOSwSv1Xlbv5

There's a good chance there will be everything you need in there. Even if you find you need a more specialist flat belt for the capstan, the generic belts will make it easier to work out the size required. I buy one off belts from CPC.

[Martin Bush]

Thanks Paul - there's no risk there is there at that price.

I saw a video on YouTube where some chap had replaced the belts with elastic bands he found around the home. I won't be doing that of course as I expect they'd go sticky pretty quickly.

[Martin Bush]

OK, belts ordered.

I have found that the power socket, rather than being fig8 as I thought is actually a rectangle not wide enough to accept my generic lead. I'm not familiar with this plug - is there any sort of adaptor for this or should I go down the battery route?

The power input is 240v, batteries 6v - safer I suppose

[Nuvistor]

I would get it working on batteries, then sort out the power side.

[camtechman]

Martin,

The power input is 240v

IMPORTANT !!

Are you absolutely/100% sure that the 'socket' is for 240V AC, does it say or is it printed somewhere !! Sometimes, where the 'socket' is fitted, it should printed on the case, nearby.

The reason for this question is that, this type of connector was used mainly in the 70's and very popular.

But, unfortunately, some manufacturers used them for mains input, whilst other manufacturers used the very same 'socket' for use with an AC to DC adapter.

This lead to major & dangerous problems. i.e. A lead which was designed for use to supply mains voltage to an AC machine could also be plugged into a machine that was designed only to run off an AC to DC supply. The result, to the AC/DC version was disastrous !!

The result being the discontinuation of that type of plug & socket and the introduction of the Fig 8 type.

However, you can still but the 'plug' from CPC/Farnell into which you can fit a two core mains lead.

Here's the direct link:
http://cpc.farnell.com/unbranded/cn-...m%2Fw%2Fsearch

[paulsherwin]

The warning is timely, but only a small number of manufacturers used these connectors for a low voltage connection. They were the standard mains connector for Japanese, Taiwanese and Hong Kong stuff for a few years before the 'figure of eight' connector became popular.

[Martin Bush]

I am pretty sure it is 240v AC but I will check later on and report back.

[TonyDuell]

If you take a look inside, you should see a mains transformer if the power input connector is for mains. Two wires from the transformer (the primary winding) will connect to the pins of that connector directly (it is very uncommon to have a mains switch or fuse in this sort of cassette recorder).

The other thing to try (without even opening the case) is to measure the DC resistance between the pins of that connector with your multimeter. If it goes to a mains transformer, I would expect a few hundred ohms of resistance between the pins. If it's a DC input, the resistance (with the machine turned off, in stop mode, etc) would be a lot higher, possibly infinite.

[Martin Bush]

Hello again.

I can confirm that the power socket is for 240v AC. I will, however, start with batteries I think just for ease.

Martin

[camtechman]

Martin,

By the way the connector (as per CPC link) are becoming hard to find and I think CPC will discontinue them when stock is gone. p.s: I have no connection to CPC.

[Martin Bush]

Thanks. It will be worth me getting one.

Any idea what the postage is from CPC as this is under their free threshold (if I buy just one)?

[Martin Bush]

Ignore the question above - I thought I'd have to set up an account to find out the postage charges, but in the end I didn't.

Is there a sticky or thread on cassette deck servicing similar to the one on record decks? I've found that my machine works and while I plan to renew the belts and clean the tape path, I was also wondering if there's any need to clean or lubricate any of the workings.

[paulsherwin]

They vary a lot so it's difficult to generalise.

I generally don't relubricate in the absence of a fault. I clean any idler wheels, mating surfaces and pulleys with meths. I reset the azimuth, and reset the tape speed using a test cassette and CD if this is reasonably easy to do. Obviously the tape path gets a good clean.

[Martin Bush]

Thanks Paul.

I remember having a tape speed cassette when I worked in a hi-fi shop in the 90s (I was largely in charge of cleaning the windows and putting the rubbish out!) and was wondering if these were still available - are they? As I recall it worked in a similar way to a record deck strobe disc.

[paulsherwin]

The correct way to set the speed is to use a commercially produced test tape and frequency counter, but I didn't have access to those, so this what I did.

Generate some suitable tone on a computer, and burn it to an audio CD. Record the CD onto a cassette using a known good cassette deck. Play the cassette in the deck to be adjusted listening on one ear of a pair of headphones, while playing the CD over speakers. Adjust the motor speed until the tones are the same, and then adjust for zero beat.

You probably don't need to worry about this with your TP79 unless the speed is grossly out, and it may not be easily adjustable anyway, but I normally do it with hifi decks.

[Martin Bush]

Apologies for the question bombardment, but I am on a roll with this one which makes a nice change.

Cleaning tape heads, capstan and pinch roller etc - meths or IPA or either? I ask as meths is mentioned above so I suppose I know the answer to part of my question, but I have some IPA to hand. I don't want to use the wrong stuff ideally nor buy meths if I don't need to (the stuff I've had in the past has been horrible).