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Vintage Tape (Audio), Cassette, Wire and Magnetic Disc Recorders and Players Open-reel tape recorders, cassette recorders, 8-track players etc. |
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15th Jun 2018, 9:07 am | #1 |
Moderator
Join Date: Feb 2006
Location: Wembley, Middlesex
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Wire recorder model 50
I have been asked to restore a Model 50 wire recorder made in 1940 by Utah Radio Products.
I've never seen let alone repaired a wire recorder. I would imagine that I treat the electronics in the same way that I would service any piece of electronics from that era. ie replace all capacitors, replace out of tolerance resistors, renew suspect wiring using silicone wire. Make copious notes. The mechanics would be similar to any conventional tape recorder. Does anyone have any thoughts on this? |
15th Jun 2018, 11:30 am | #2 |
Dekatron
Join Date: Jul 2008
Location: Kington, Herefordshire, UK.
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Re: Wire recorder model 50
Major difference in the mechanics is the baling mechanism which lays the wire up evenly on the spools, frequently a victim of hardened grease and the cause of incredible tanglings and blasphemy if it fails.
The mechanism will be reel drive and wow like a banshee with its tail stuck in the door. They all do that, sir. Bias is usually DC. |
15th Jun 2018, 10:52 pm | #3 |
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Re: Wire recorder model 50
Watch out for badly adjusted breaking or you will have wire everywhere.
I always tent to keep a finger on the lazy spool when stopping from rewinding my KB EWR60 Mike |
16th Jun 2018, 5:25 am | #4 |
Octode
Join Date: Mar 2006
Location: Lund, Sweden
Posts: 1,632
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Re: Wire recorder model 50
If the bailer is working but is maladjusted (too high or too low) the layer of wire on the take-up spool will not be flat but lean at an angle. It's not a serious problem, but I think would increase the tendency for the wire to tangle if the tension is not right.
The main thing with wire recorders I find is that the technology is old, so there are a number of outdated features, such as combined record/playback/erase heads, with a pole piece with two gaps, one for the erase and one for the record/playback function. Don't know about this particular machine though. The recording emphasis and playback tone correction tends not to follow a standard but is unique to every model. The fact that the layers of wire lie directly on top of each other (compared to a tape recorder, where the magnetic layers on the tape are always separated by the tape base when spooled) means that there will be a lot of contact copying between adjacent layers, leading to a fairly bad signal-to-noise ratio. Especially after the end of a recording if there's nothing further recorded, there will be ghostly echoes of the recording for several minutes. Since the wire speed is so high to start with, rewind (and wind, if available) speeds will not be especially high. I think four times the play speed would be typical, which doing the math means that a spool with an hour's worth of recording time takes a whopping 15 minutes to rewind. |
16th Jun 2018, 7:41 am | #5 |
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Re: Wire recorder model 50
I will tell the owner that I'm happy to have a go but it may take several days while I get more information.
How does the bailer work? Can someone supply diagrams? |
16th Jun 2018, 8:02 am | #6 |
Dekatron
Join Date: Apr 2012
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Re: Wire recorder model 50
Is it not like a fishing reel where the take up spool moves up and down as it is reeled in giving an even lay.
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16th Jun 2018, 9:57 pm | #7 |
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Join Date: Mar 2011
Location: Basildon, Essex, UK.
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Re: Wire recorder model 50
No, it is the recording/playback head which moves up and down, the wire travels through a slot in it, so it winds onto the take up spool evenly and not in a pile. Movement is caused by an eccentric cam.
There are plenty of videos of wire recorders on You tube, including one of my KB EWR60, which looks somewhat different to the Utah. https://www.youtube.com/watch?v=ecDDgWDHlrY Mike Last edited by crackle; 16th Jun 2018 at 10:03 pm. |