Uher 4000 Report L - advice?

[andreanelsen]

Hi - I'm a newbie here and just getting into vintage tape. My dad had a Uher Report 4000 L which he used to record all kinds of family events in the 1960s-90s. I would like to convert the tapes to digital, but first I have to get the Uher working again! And that has gotten me interested in how it works and what skills I'll need. I have some simple electronics experience and plenty of interest but I've never messed around with a complicated machine.

Right now the machine seems to have trouble with some tapes and not with others. The first tape I tried to play on it - on the two slower speeds, the uptake reel stopped moving after a second or two. It seemed to just quickly tire out. On the faster speeds, it warbled for awhile, going at an inconsistent speed, but after a few minutes it played fine at those speeds. It would not fast forward at all, not at any speed.

But with a different tape, I found it would play at all speeds and fast forward. Does that say something about the tapes? Do tapes need maintenance?

It won't rewind under any circumstances.

There's a 43-minute video online about how to fix and maintain a Uher 4000, which I followed. I cleaned the heads, added some oil in places, and although the existing belts are intact and functional for now, I ordered a new set on eBay.

I've read that certain capacitors are prone to going bad. So I was wondering if anyone here has advice about a trustworthy source for learning to test and work with capacitors for someone who has never done that before? Of course there are a million YouTube videos - but anything entry level in particular related to tape recorders or Uhers that folks here might recommend?

Any ideas why the rewind function doesn't work at all? There's a rubber coated rod that spins and I believe is supposed to contact the supply wheel face and make it spin backwards, but that contact doesn't appear to be happening.

Finally I've heard that it's important to demagnetize the player if it hasn't been used in a long time. Is this correct? My dad lectured me on the importance of keeping the tapes away from magnets, so now I'm scared to even have a magnet in my house! The tapes are precious and first and foremost I want to protect them. They've been stored in a cool, dry environment for decades. What I've heard of them so far sounds excellent.

Thank you all!

[brenellic2000]

Re the tapes. There is a major problem with some vintage tapes known as 'sticky tape syndrome'. It is the chemical degradation of the glue that binds the iron oxide to the plastic tape.

It is evident in a resistance to unpeel; squealing/screeching; odd running speeds. Pre 70s tapes are generally OK but certain post-70s are problematic. Such tapes may not be recoverable.

[paulsherwin]

Also known as 'sticky shed' - you'll find lots of info if you google. It mainly affects American 1970s pro formulations from people like Ampex and Scotch, but there have been cases with many brands.

If the content of your tapes is particularly important to you, it would be a good idea to pay a professional to recover the contents rather than trying to play them yourself on a dubious recorder. Tapes with sticky shed can usually be read using specialist techniques.

[Ted Kendall]

Originally Posted by paulsherwin

If the content of your tapes is particularly important to you, it would be a good idea to pay a professional to recover the contents rather than trying to play them yourself on a dubious recorder. Tapes with sticky shed can usually be read using specialist techniques.

As one who is such a professional, I'd add that that it is best not to attempt recovery yourself, get in a jam and then call in help. I've had tapes come in where the customer has started playing or spooling them and caused irretrievable damage. Conversely, if the tape is treated before any attempt to play it is made, the chances of recovery of the information are very good.

Incidentally, sticky shed is not the only mode of binder breakdown. Some Scotch formulations appear to spool well, with just a faint ripping sound, which is the matt backing stripping the oxide off. Don'r ask me how I know - but fortunately there was another copy of the material extant...

If retrieval of the information rather than making the machine work is the priority, I'd set the Uher aside and get the tapes transferred.

[DMcMahon]

Using a tape that suffers from sticky shed can/will result in sticky/gummy tape oxide being deposited onto the tape heads and tape guides, these deposits can be very difficult to remove/clean.

This can be very severe and can make mechanically playing or fast winding the tape difficult, sometimes impossible, if tape can be played the sound can also be poor.

David

[DMcMahon]

Originally Posted by andreanelsen

I've read that certain capacitors are prone to going bad. So I was wondering if anyone here has advice about a trustworthy source for learning to test and work with capacitors for someone who has never done that before?

Capacitor replacement is unlikely to be required for the 4000 series, problem capacitors are more common on older valve (thermionic)/vacuum tube equipment. Solid state (transistor) equipment like the 4000 series generally have far less problems with capacitors, so at this stage I would not be concerned with checking out the capacitors.

Capacitor replacement particularly recapping is quite a big subject and there are a wide range of opinions covering it.

David

[TIMTAPE]

Possibly weak fast wind/rewind is due to a stretched belt. Very common. At the beginning of a tape though, rewind is always more difficult due to the 'gearing' effect of much tape on the supply reel and little wound onto the takeup reel.

[DMcMahon]

Does the Supply reel table rotate when Rewind is selected when there is no tape loaded/threaded ?

David

[andreanelsen]

Thank you all! This is very helpful. About the sticky tapes - those tapes were ones that I got separately, and was using them only for the purpose of testing the machine. They were more recent - from the 80s or 90s I think. The sticky tapes aren't sentimental or important. The tapes from my dad are the ones that work. Those tapes mostly date back to the 60s and early 70s.

I won't try to play the sticky tapes again!!! But since I tried to play them before I posted here - does that mean I need to do something special to clean the heads? Is it dangerous to run good tapes through the player after having tried to run a sticky tape?

[andreanelsen]

Originally Posted by DMcMahon

Does the Supply reel table rotate when Rewind is selected when there is no tape loaded/threaded ?

David

No, it doesn't rotate either with or without a tape loaded.

[brenellic2000]

If you've only tried a couple of 'sticky' tapes, you'll probably be OK. All tapes shed some oxide in use - some worse than others - without too much detriment. Heads and guides should be cleaned regularly. I use meths, others use Iso while Revox says don't use alcohol! lf the crud is immovable, don't try to shift it with anything metallic.

[TIMTAPE]

Originally Posted by andreanelsen

...I won't try to play the sticky tapes again!!! But since I tried to play them before I posted here - does that mean I need to do something special to clean the heads? Is it dangerous to run good tapes through the player after having tried to run a sticky tape?

Without seeing it, it's hard to say. At the least, the SSS tapes often dirty up the read head which can make for very weak and muffled sound on any tape subsequently played. At worst, almost no sound and sticking and jamming of good tapes.

Again for me, hard to say whether any deposits will damage your 60's and 70's recordings. Like a few others here I've done a lot of this work. As soon as I'm aware of even small deposits on the tape path, which I check very often, I clean them off. So for me the issue of whether valuable tapes become damaged in this way never arises because I never allow it to arise.

Another potential issue with SSS tape deposits is from memory the Uher L uses a small felt pad called a pressure pad to press the tape against the read head. Tapes with SSS usually have a dull black layer called "back coating" which unlike the very smooth backing of older tapes is designed as a rough finish and can cause friction problems with machines with a pressure pad, even tapes which have no Sticky Shed. If tapes do have sticky shed the problem may be exacerbated, with the pad becoming caked with tape debris, further increasing friction complications.

Really the machine's tape path around the central head block where the tape is threaded needs to be carefully inspected and cleaned as necessary. This includes of course any felt pressure pad which may need replacing. They often need replacing anyway.

Pictured below are typical heavy orangey grey deposits from a Sticky Shed tape onto a machine's tape path. The friction and drag on the tape was so bad in this case that it stretched and then broke the valuable tape in two. It also took some time to remove the deposits completely.

[DMcMahon]

Originally Posted by andreanelsen

No, it doesn't rotate either with or without a tape loaded.

Assuming that the lack of Rewind is not due to badly gummed up heads/tape path from SSS (Sticky Shed Syndrome) tapes and that the motor and motor control circuit is good (very unlikely to be bad) then lack of Rewind sounds like a mechanical problem with the associated rewind hardware.

With the unit upside down and positioned so that the motor is at the bottom of the unit, with cover removed you will see 2 drive belts coming off each end of the motor shaft. The left hand side (shorter belt) is the fast wind drive belt which connects to the Seesaw assembly which has 2 conical friction wheels one at each end of a shaft.

As per Tims suggestion at Post 7, check the fast wind belt is not loose/slack, it should be reasonably tight, also make sure it is clean/not greasy.

Makse sure that the black rubber brake rollers are released from making contact with the reel tables, when fast wind is selected in either direction.

With either Rewind or Fast Forward wind selected both friction wheels should rotate and the black rubber section on the appropraite friction wheel should contact the underside outer section of the reel table which then should rotate the appropraite reel table. Make sure the friction wheel rubber sections are clean/not greasey.

David

[DMcMahon]

Yesterday I was trying to explain what a tape recorder was to my 3 year old grandson, he seemed very interested, so I dug out my Uher Report Monitor 4000 (which mechanically is quite similar to the 4000 Report L).

I recorded him talking and singing, he liked hearing the playback but after 30 minutes said "what else can we do now Grandad".

During recording/playback discovered that it no longer (worked fine the last time I tried it a while ago) will fast forward wind at all, even when no tape is loaded. Can see that when the Seesaw assembly tilts down in Fast Forward Wind that the rubber (white in the case of the Report Monitor 4000) on the friction drive is not contacting/fully contacting the reel table, hence no fast wind drive to the Take Up spool.

So similar symptom to your 4000 Report L but in the opposite wind direction.

David

[DMcMahon]

Looking at the servIce manuals for the 4000 Report L & 4000 Report Monitor there are a couple of set-up procedures for the Rewind/Fast Forward operation that possibly might be relevant.

I am not saying that it is likley to be your Rewind problem but something to consider if everything else checks out.

The procedure covers adjusting (by bending) some sprung backing plates to get correct pressure of the friction wheels onto the reel tables when fast wind is selected. Even though I get the gist of the procedure and associated drawing I do not fully understand the operation because do not know what happens underneath the seesaw assembly, so for my fast forward not working I will not jump in and try this adjustment until I get a better idea how it all works.

To do the adjustment one has to remove the seesaw assembly. On mine I will remove the seesaw and hopefully then can work out how it all works and decide then if making adjustment to the fast forward backing plate would help.

David