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#1
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1982 jvc hr-7300u
There are five belts in this unit: The square take up belt that runs from the top of the capstan to a white pulley was about 48 mm in diameter. When I replaced it with a new one of the same size, it didn't work. So, I tried smaller sizes until the take up reel turned reliably. ~40 mm did the trick. The flat capstan belt was completely melted. It appears to have been about 101 mm in diameter. I didn't have a replacement, so I made one out of vinyl electrical tape. After six hours of testing, it still works consistently. The loading motor belt was fine and hasn't been measured. The counter mech uses two belts. The first is ~63 mm in diameter and goes from the take up reel to a double pulley. The second belt goes from the double pulley to the counter mech. It's about 32 mm in diameter. There are several date code locations including: the inside of the front panel, the forward/reverse motor, and the top of the loading mech (month & day). As you can see, this unit was manufactured in December of 1982.
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I'm in need of service manuals for the following: Magnavox 19C315-CC, Emerson ECT-1300A (TM0110E), Sears 401.50300900 Last edited by colectorad; 10-07-2016 at 02:49 AM. |
#2
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Unless that flat belt was wider than 1/4" I'd have made it out of rubber bands...if the band is too long or short splice it with another band and super glue.
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Tom C. Zenith: The quality stays in EVEN after the name falls off! What I want. --> http://www.videokarma.org/showpost.p...62&postcount=4 |
#3
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I tried the rubber band fix which is ok and not on the capstan drive unless you want quivering sound and a shaky picture.LOL....................
One of my main apps for the rubber band trick is the capstan belt of a Toshiba beta HiFi (the original is almost exactly rubber band size) it's always ran smooth as silk with a rubber band there..... I've never known where or how to order belts so most of my mechanical equipment that did not have good belts or use ones from gear I've scrapped are 'living on office supplies' so to speak. Last edited by Electronic M; 10-05-2016 at 04:01 PM. |
#4
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Looks like you can still get a belt kit from http://studiosoundelectronics.com/mbk-06.htm to restore it properly.
3 kits: Belts only, with rubber tires, and with pinch roller. |
#5
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What a cool project! I've only seen one of those models back in 1999 when I put new belts on it. Hope you get it working again!
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Audiokarma |
#6
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Quote:
Quote:
This unit 'works' as it is. All it could use outside of a proper capstan belt is a sealed relay. The 'Omron 62V-2' relay that it uses appears to have never been reliable by design. SP playback & reverse search suffer from it. I've seen mid-'80s recordings made by this machine with interference from the relay not switching the heads over all the way.
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I'm in need of service manuals for the following: Magnavox 19C315-CC, Emerson ECT-1300A (TM0110E), Sears 401.50300900 |
#7
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#9
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Looks like it should work. Not sure what the variations of the part number mean, no specs available I could find.
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#11
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The price its right but I don't know those relays. Buy one and try it! All you have to lose is $3 and the time it takes to get here from China.
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#12
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**Update**:
I was wrong, the G2V-2-NV1 relay has a coil resistance of 340 ohms and does not have the voltage rating printed on it. I purchased a pack of the HK19F 12 volt relays; they have a coil resistance of 720 ohms. -- After installing the HK19F, removing it, and reinstalling the G2V-2, it would appear that one or more of the wires that connect the switching board to the head drum have broken. It will only turn back and forth slowly before auto returning the tape when 'play' is pressed. Does anyone have the procedure for disassembling the head drum? The connections to the head switching board have been mended.
__________________
I'm in need of service manuals for the following: Magnavox 19C315-CC, Emerson ECT-1300A (TM0110E), Sears 401.50300900 |
#13
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I have continuity between the black, brown & green wires, then the red, yellow & white wires. The drum still isn't spinning up. Which voltages should be present? I don't have the service manual.
__________________
I'm in need of service manuals for the following: Magnavox 19C315-CC, Emerson ECT-1300A (TM0110E), Sears 401.50300900 |
#14
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Are you working on the head relay board or the cylinder motor? Two separate circuits. The cylinder motor I think has a plug under the deck. But without a manual I am relying on memory from repairing them 30 years ago.
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#15
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Quote:
The power board connects to the servo board which has these signals labeled: I measured the following while switching the unit from 'standby' to 'on': "13V" - 13.19V "12V" - 12.78V "22V" - 25.7V "Drum M. CTL" - 8.6V (steady) "Drum Phase" - 6.34V (steady) "Cap M. CTL" - peaks at 3.75V before quickly dropping to 0.65V "Cap Discri" - 7.25V (steady) "Cap Phase" - constantly moves between 4V and 6V What does this tell you?
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I'm in need of service manuals for the following: Magnavox 19C315-CC, Emerson ECT-1300A (TM0110E), Sears 401.50300900 |
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