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-   Vintage Tape (Audio), Cassette, Wire and Magnetic Disc Recorders and Players (https://www.vintage-radio.net/forum/forumdisplay.php?f=35)
-   -   Uher 4000 S (https://www.vintage-radio.net/forum/showthread.php?t=708)

jdp 16th Nov 2004 5:54 pm

Uher 4000 S
 
Machine #2 that I'm asking about.

Our library was given a Uher 4000 S so staff could play tapes recorded at 15/16ths in/s. It works well, except that about 20 minutes into playback, tape speed slows somewhat. It's not terribly slow, but too much for re-recording. I do not know if it slows more with extended use.

Any tips on what might be causing the slowdown? A staff member at the library says they have several vintage recorders (not Uher), and similar problems have infiltrated them.

Thanks in advance!

reelguy 16th Nov 2004 8:34 pm

Re: Uher 4000 S
 
Hello JDP and others interested in vintage recorders.The problem with the Uher 4000 speed {And also other old Tape recorders} is most likely that the belts are quite worn and need replacing. Also it has a couple of other rubber parts which get worn out.These machines are quite old now 35 to 40 yrs.To be working at all is amazing.Belts may be obtained from www.elektro-ersatzteile.org .I think it is a German company. Havent bought anything myself but they do say they have belts for Uher and other mainly european. The belts on the Uher arent too difficult to change but there is a knack to it.. Hope this is of help...... Reelguy . Ps If the address doesnt work try, Eberhard Hewicker in the search bar its the same place

jdp 16th Nov 2004 8:50 pm

Re: Uher 4000 S
 
Thanks for the tips, reelguy.

I should have mentioned that I replaced the belts first thing. The long one was so loose it almost removed itself.

I had not given that much thought to the other rubber pieces, though I did clean them (with non-slippery cleaners) during the first run-through. You're right -- there's a rubber drive piece on each end of the shaft, one end turning each reel. And the rubber on the bottom of each reel could be suspect, though all look in pretty good shape. This particular machine had not been used all that much, so I figured it couldn't be worn down. Maybe so.

You're also right about years in service -- the S model was delivered 22 May 1964. The owner had kept all paperwork, receipts, etc.


Stewart 17th Nov 2004 8:55 am

Re: Uher 4000 S
 
Hello there,

The rubber pieces at each end of the rod and under the reels that you describe are primarily used for fast winding of the tape rather than play / record transport.

I would examine the capstan wheel and its stepped flywheel driver. The angle and tension that this stepped flywheel contacts the surface of the capstan wheel can make all the difference to reliable running in these machines. If wrong, friction could be softening the rubber surface here after a time - leading to more friction and slower running. If I recall correctly the stepped flywheel position can be adjusted.

The motor used in these machines has given me a good few problems over the years - but none that fit in with the symptoms you describe. Just as well as they not fun to strip and overhaul!

Good luck

Stewart

jdp 17th Nov 2004 3:35 pm

Re: Uher 4000 S
 
Stewart,
Thank you for valuable insight for the Uher. I had wondered if the rubber on the capstan flywheel might be a problem, but I was thinking about wear, not excess friction. I will look for adjustments for the driver and see how that affects play speed.

Quote:

...I would examine the capstan wheel and its stepped flywheel driver. The angle and tension that this stepped flywheel contacts the surface of the capstan wheel can make all the difference to reliable running in these machines. If wrong, friction could be softening the rubber surface here after a time - leading to more friction and slower running. If I recall correctly the stepped flywheel position can be adjusted....

Stewart


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