8 track foil and foam replacement

[defender]

I happened upon an Akai CR-81 8 track recorder, a set of speakers and a box of 42 cartridges for cheap on the car boot (can't resist cheap old junk).
Cleaned the switches and pots with Deoxit and seems to function ok.
Got the instructions and the original purchase receipt from 1/11/73 £77.90 no vat from Hardman Radio Manchester.
Anyhoo I've been playing the tapes and so far 2 have failed on the foil splice.
I have a reel to reel splicing block but I'm wondering if anyone knows of an alternative to buying foil and foam on eBay, as in a tried and tested alternative.

[DMcMahon]

Some time back when I got into 8 track players/recorders I purchased several sets of foam from online sellers.

After repairing some 8 track cartridge foam and closely looking at the cartridges in operation, it strongly appeared that the foam was incorrectly dimensioned (thickness I think). It seemed that the foam was not contacting/putting any pressure on the tape when tape was running. I need to revisit this and investigate further. I maynot be describing the issue very well.

David

[DMcMahon]

The first attached photo in Post 26 of this linked Thread partially explains what I saying above in Post 2, subsequent posts explain more.

https://www.vintage-radio.net/forum/showthread.php?t=175035

David

[defender]

Originally Posted by DMcMahon

The first attached photo in Post 26 of this linked Thread partially explains what I saying above in Post 2, subsequent posts explain more.

https://www.vintage-radio.net/forum/showthread.php?t=175035

David

I can't remember if I tried draught excluder tape ages ago or not or just went to b&q looking for suitable tape, it was a while ago.
To me on the whole it's probably the foil splice that's the most important, but I've taken carts apart before and the tape has a mind of it's own and has just ended up in the bin.
One tape went on the splice and stopped, the next one made a crinkly mess inside the player so I wound the tape onto a reel to reel spool for now.
Mostly the foam pad doesn't seem to make a large amount of difference.

[Reelman]

In the past I have successfully used draft excluder to replace the foam as it appeared to be exactly the same material. It can be done carefully without opening the cartridge, which I’ve never relished doing! All carts that use foam will definitely need it replacing, in my experience when it is missing the reduced head-tape contact does decrease the treble response. I haven’t looked recently at draft excluder, perhaps it is no longer made of foam rubber so may not be suitable?

The splice with the foil will also be very prone to failing so replacement is necessary. Finding the correct splicing tape (please don’t use Sellotape) and switching foil is not so easy so it is worth using the commercial solutions offered for 8-tracks.

It’s always worth searching out the relatively rare tapes that use the sprung felt pad. You may not like the original music but these tapes are good candidates for re-recording if you are lucky enough to have a recorder.

Peter

[chriswood1900]

Another vote for soft foam draught excluder foam, worked well for me.
BTW if you need the service manual it is on HiFi engine, if you are not subscribed send me a PM as I have a copy of that plus the user manual.

[af024]

Whilst I've found some draught excluder can be just about right as regards its 'squidginess' (and even colour if you want to go that far), it rarely seems to be thick enough in my experience. The stuff that is just about right as regards thickness unfortunately tends to be far too wide. You just can't win.

[defender]

Originally Posted by chriswood1900

Another vote for soft foam draught excluder foam, worked well for me.
BTW if you need the service manual it is on HiFi engine, if you are not subscribed send me a PM as I have a copy of that plus the user manual.

Hi yes I'm a member and I got the user manual with it thanks

[defender]

Most of the cartridges I have cost a pound or less so some of the rubbish ones could be recorded over, I have 2 recorders Akai and Sharp and I think 2 other players.

None of the cartridges I have have been reconditioned, the ones I got with the Akai are in quite nice condition some look newish, whereas some of the others look like they've been in a cardboard box in a damp shed.

The Akai came with 1976 "Frampton comes alive", never actually listened to that before, but I have now on 8 track.

Thanks David the thread you posted was very interesting to the pitfalls of cartridge refurbishing.

[DMcMahon]

While visiting a DIY store yesterday I purchased some foam draught excluder strip advertised as "Thick".

Unsure if its thickness is any larger than what I have previoulsy purchased online, so may not be of any use unless try doubling 2 layers up.

It looks too wide so would have to be trimmed doiwn with a sharp knife/scissors.

Need to find some time, to get back to 8 track cartridge foam replacement and try the draught excluder.

David

[ben]

Years ago I bought a roll of adhesive aluminium tape, which I have used to add stop foil to reel to reel tapes and repair 8 tracks. It cost about 3€ and will likely last me out! Over the decade or so I have been using it I have noticed no seepage of the adhesive and it has lasted extremely well. Best 3 notes I ever spent!

As for the pressure pads: It is vital that the sponge ones are replaced. If not, you get poor sound and the tape will creep up and down the capstan, leading to uneven winding and chewing/entanglement. I used small pieces of packing plastic foam, you can also reuse the plastic sheet off the original pad if the surface is not smooth enough.

Would be interested to hear results of your draught excluder tests, David! Keep us posted.

Edit: If you still have problems with poor tracking and tape tangling, it could be that the capstan shaft is worn smooth or covered in the graphite off the tapes. Common in car units and well used machines. A quick gentle application of some fine sandpaper will restore a little grip to the shaft, but use this as a last resort and do not overdo it.

[8 Tracker]

Congrats on your purchase. Those Akai decks are my personal favourite. They seem to give the best results with their large AC motors and heavy flywheels.

Like Ben, I bought a roll of aluminium self adhesive foil a while ago. But for the life of me, I can't remember where I got it. I find some splices are fine, wheras others are just waiting to fall apart, sometimes with disastrous results.

Nowadays, I open up every new (to me) cart I get as a matter of course. As others have said, the sponge pads always need replacing. I collect bits of foam from various sources and just cut it into strips with scissors. The foam I use is always wider than the tape, but it seems to give very good results. I find with well played carts that leaving the foam face bare is best, as the foam collects all the loose graphite from the back of the tape, which can then be blown off. Unplayed or little used carts can benefit from a layer of Sellotape on the front face of the sponge to ease passage. Yes, it looks a bit of a mess as it's all hand cut, but it's reliable and can easily be replaced if something better comes along.

The most popular carts seem to be the ones held together with five plastic pegs and these are probably the easiest to open. Just insert a pair of long-nosed pliers in the front in one corner and open the pliers. The peg just pops open. Repeat in the other corner and the the remaining three pegs usually pop open with hand pressure.

Another bit of my servicing routine is to add a tiny drop of oil to the pinch roller shaft and the tape hub shaft. This eases things along and stops any tendancy of the tape hub to rumble on the shaft.

As you can probably tell, I rather like this tape format.
Mark.

[Martin Bush]

My top tip is not to drop the cart when you have opened it. You can guess why I say this!

My other top tip from replacing the splice myself is to play a new cart in the machine and listen for when the track changes and immediately whip the cart out. If you are quick enough you will have good access to the splice or it will break and you will have got it out before one end of the tape disappears.

[DMcMahon]

Originally Posted by Martin Bush

My other top tip from replacing the splice myself is to play a new cart in the machine and listen for when the track changes and immediately whip the cart out. If you are quick enough you will have good access to the splice or it will break and you will have got it out before one end of the tape disappears.

To clarify a little for 8 track newbies:-

The track changing is when the splice activates a sensor which energises a solenoid to change to the next track/Programme, there will be a noticeable click or clunk when the solenoid is energised, i.e. it is not the next music track, when there is more than 1 music track per Programme with the last music track not having been played.

The cartridge has 4 Programmes numbered 1 to 4, each Programme (or track) can have 1 or more music tracks (i.e. individual songs/music recordings), most typically 4 is the maximum.

So when determining when the splice is close you need to know what is the last song on that particular Programme, this will be shown on the cartridge label details, but occassionally the label maybe missing or in such a bad condition it is unreadable. If one is not concentrating it is quite easy to miss the splice operation.

Some times the last song on the Programme may be split across 2 Programmes, e.g. if there is only 2 minutes of play time left on Programme 2 and the song is 4 minutes then the last 2 minutes (approximately, it may not be an exact 50/50 split) of the song will be split onto Progamme 3.

The splitting of a song maybe abruptly cut-off or cut-in or smooth with fade out or fade in.

David

[TonyDuell]

if you're going to do this 'seriously' you could modify a low-end 8-track player with a DC tape motor so that the tape contact, rather than operating the track step solenoid, operates a latching relay that stops (and possibly short-circuits, to give braking) the motor.

Then when the foil comes round, the tape stops and you can pull out the cartridge and have access to the splice.

[factory]

Originally Posted by TonyDuell

if you're going to do this 'seriously' you could modify a low-end 8-track player with a DC tape motor so that the tape contact, rather than operating the track step solenoid, operates a latching relay that stops (and possibly short-circuits, to give braking) the motor.

Then when the foil comes round, the tape stops and you can pull out the cartridge and have access to the splice.

That probably a good use of a car 8-track player that is either, very tatty, or the unobtainium amplifier ICs are blown from incorrect polarity.

David

[defender]

A couple of mine stop after one play and they stop on the foil strip.

[TonyDuell]

I knew my 8-track recorders stop after stepping the head from track 4 to track 1 in record mode (which makes sense, to avoid overwriting the track 1 you've just recorded) but on checking the circuit diagrams they also do this in fast forward mode. So it would stop with the heads on track 1 and the splice exposed. (If you've got any sense you'd put the head on track 4, press FF and it'll stop the next time the splice/foil comes round)