Cassette Tapes

were

esuhl wrote: »

But how do the demagnetisers work? How do they know the magnitude of magnetic flux affecting the tape head? How do they calculate the exact flux exposure needed to cancel any magnetic effect...?

I mean... do you remember, as a kid, making a compass by magnetising a pin or needle and floating it on water? Now imagine you have a dozen pins, some magnetised to varying degrees, some not. How are you going to use a magnet to uniformly demagnetise those pins?

They are AC. From hdd platters you need 125% more energy to demagnetise something???, so assume all media is similar to some extent

So you have this soldering iron looking object. you run the tip of the degausser over the head in circles, while slowly pulling the degausser away from the head to avoid building up magnetism.

Those old tvs, not the plasma ones:), but the tube ones also had a degaussing coil in the back around the tube. When you switched on from cold that sudden rush/hum you heard of voltage was the degaussing coil

Voyager2002

baza52 wrote: »

Wind the tape from to start to finish then back again to make sure it is tensioned properly.

Do this BY HAND. Use a pencil to turn the tape at a reasonable speed.

esuhl

were wrote: »

They are AC. From hdd platters you need 125% more energy to demagnetise something???, so assume all media is similar to some extent

So you have this soldering iron looking object. you run the tip of the degausser over the head in circles, while slowly pulling the degausser away from the head to avoid building up magnetism.

Ah, right. I had a battery-powered demagnetising cassette. As the spools turned it would move a tape head inside the cassette up and down over the tape-deck head.

I always wondered whether it actually did anything!

were wrote: »

Those old tvs, not the plasma ones:), but the tube ones also had a degaussing coil in the back around the tube. When you switched on from cold that sudden rush/hum you heard of voltage was the degaussing coil

Isn't degaussing a monitor a bit different...? I thought degaussing just briefly earthed the tube to release a build-up of static electricity...?

Heedtheadvice

I thought degaussing just briefly earthed the tube to release a build-up of static electricity...?

Nope, as per were's post.
Professional colour monitors were often also regularly degaussed by a quite big external degausser. The electrons from the three guns (red, green and blue) passing down the tube had to be accurately aligned to hit the correct colour phosphor dots. If the tube had slight residual magnetism then the electrons were incorrectly deflected causing colour distortions.

The problem was bits getting magnetised. It has nothing to do with static.


........now what was the OP's question.........?

forgotmyname

Originally Posted by baza52 Wind the tape from to start to finish then back again to make sure it is tensioned properly.

Voyager2002 wrote: »

Do this BY HAND. Use a pencil to turn the tape at a reasonable speed.

A Bic pen is the perfect size to do this, insert into the empty side and spin with one hand.

Are the felt pads present? Possibly turned to dust by now.

ThemeOne

I've taken the top of the deck and the drive belts look OK - I'm no expert but they seem to operate smoothly and no visible degradation in the belts themselves. I've ordered a new set though, just in case.

I've also cleaned the heads, pinch roller etc with isopropyl alcohol. I've noticed one of the tapes giving trouble is leaving small deposits on the play head, so I suppose that means the tape is basically at EOL?

I don't know the exact age of the deck, as haven't had it from new, but I would guess early 90s.

Heedtheadvice

The deposits will be the oxide layer that contains the recordings. Best copy that one soon and clean the deck frequently between sections and at the end.
The oxide deposits will eventually loose the recorded data, particularly the high frequencies, and the build up of deposit on the play head will reduce the rendition of high frequencies of all tapes till it is removed.

Norman_Castle

The decks 30 years old. The belts can stretch over time.

Robisere

It's dead, Jim.

It was recorded music, but not as we know it, not as we know it.

The only use I had for cassettes, was good quality blank Memorex tapes, which I used to record my vinyl records, for use in the car cassette. Then CD's arrived and I used blank cd's for the same purpose. The result of that is that I have a huge collection of vinyl from the late 50's to the late 80's, all in perfect condition because I stored the vinyl correctly and only played them to record onto other media. Nowadays I am in the middle of recording my collection to a NAS and an external hard drive. My car has no CD or cassette player, but USB keys full of 100's of tracks and/or dozens of albums, these answer the same purpose and they do not have to be turned over at the end of a few tracks. I can also use the USB keys in my home HiFi of course, or stream the music from the NAS wherever I want.

In other words, unfortunately you are attempting to use music - playing technology which wears every time you play it and will one day be irrecoverable, if it is not already in that state. It is on a par with VHS cassettes, which wear out quicker still. Time and technology move on.

were

Norman_Castle wrote: »

The decks 30 years old. The belts can stretch over time.

And the rest. Some become brittle. but it is smootheness and the belts not gripping that could be the issues too.

Something I did not mention was the clutch. That could be slipping, but It the other tapes work......

while not the best and give bad speed control due to stretching, an elastic band could show you the possible cause