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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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Old 26th Nov 2011, 2:34 pm   #81
DOFFERY
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Default Re: Tandberg 2041 (series 2000) Erase Head Problem.

Quite correct Ricard, the three pads are there for rewinding/stop but as I mentioned in post 78 the pads should not touch the tight disc . I should have made it a little clearer I meant the pads should not touch the periphery of the tight disc, this could cause the problem on play. Sometimes the felt pad fitted to the tight disc is not centrally positioned & overlaps the disc. due to heat/wear, plus the pads have to be fitted outside the radius of the tight disc.
There is a felt pad fitted to the underside of the table which rides on a nut on the top of the fixed shaft (into which the table spindle fits) to ensure a smooth movement & without which we have metal on metal. However back tension is provided by the tight disc.

Colin.
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Old 26th Nov 2011, 3:09 pm   #82
scottie_UK
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Default Re: Tandberg 2041 (series 2000) Erase Head Problem.

I've corrected the table issue, I was not leaving enough gap so that when the tight disk moved backwards for play mode, the felt disk was in contact, but occasionally the leather pads would also rub against the tight disk ever so slightly due to the slight wabbling of it. Took be ages to get the optimum settings which involved not only tweaking the black screw beneath the table, but also the right amount of turns on the retaining plastic bolt. I've corrected the issue now, and it plays back, RRs, and FWs fine.


But:
There are two problems remaining now. One is that of erasure and and a new one which I think is capstan or pinch roller related.

Erasure:
It seems that higher quality tapes such as TDK SA35 or Ampex PRT1800 are much more problematic than the lower quality generic ones, or standard 70's BASF brand ones. The better tapes leave much more of the previous recording, with the low quality tapes providing almost satisfactory erasure, but obviously recordings with poorer frequency response.

I tried with the Bias presets, two turns one way and two turns the other on both channels and it makes no difference.

[edit]Erasure seems to be zero when I play a 1000hz tone on quality tape.[/edit]

Capstan/Pinch Roller Problem
The capstan on this device has always appears to be as fresh as a daisy, apart from a build up of brown ferrous particles from the tapes played over the years. I took the trouble to clean it with some alcohol supplied with a head cleaner for a floppy disk (a small bottle). However, now the tape speed is uneven and the device seems to wind up to speed upon playing or recording. However, the capstan looks clean. What should I do?

Last edited by scottie_UK; 26th Nov 2011 at 3:35 pm.
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Old 26th Nov 2011, 7:03 pm   #83
DOFFERY
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Default Re: Tandberg 2041 (series 2000) Erase Head Problem.

Do you mean the capstan shaft or the pinch roller Scottie, the capstan shaft shouldn't be any trouble really but the pinch wheel must be in good condition, is it too soft or shiny? It does sound like pinch wheel trouble.

Re. the erasure have you checked the 24 volt supply. Altering the bias presets will not assist the erasure, have the values for the erase head you gave sometime ago altered. ?

Glad you have resolved the table problem.

Colin.
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Old 26th Nov 2011, 7:54 pm   #84
scottie_UK
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Default Re: Tandberg 2041 (series 2000) Erase Head Problem.

Quote:
Originally Posted by DOFFERY View Post
Do you mean the capstan shaft or the pinch roller Scottie, the capstan shaft shouldn't be any trouble really but the pinch wheel must be in good condition, is it too soft or shiny? It does sound like pinch wheel trouble.

Re. the erasure have you checked the 24 volt supply. Altering the bias presets will not assist the erasure, have the values for the erase head you gave sometime ago altered. ?

Glad you have resolved the table problem.

Colin.
I'm not sure if it is the pinch wheel or the capstan shaft. However, the Capstan rubber looks in excellent shape.

Please tell me now to check the supply as the manual does not.

I'm almost ready go to give up, even my wife has said please no more I'll buy you a serviced on it you want one that badly.
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Old 27th Nov 2011, 8:55 am   #85
ricard
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Default Re: Tandberg 2041 (series 2000) Erase Head Problem.

One way to check the pinch roller is to lightly press on the rubber surface with a fingernail. If you get a dent that doesn't disappear immediately the rubber is getting old, same if it feels hard and brittle. The rubber on Tandberg pinch rollers are notorious for going bad with time. Sometimes it can look fine, but when pressing on it it's sort of soft and doesn't retain its shape. Other times the go hard, and eventually crack.

Regarding your erase problems, exactly what tape are you using? The reason I ask is when I got my 9100X many years ago, the seller had supplied a reel of Agfa tape, the type of which I don't remember. It was black, and back coated, though, and obviously required quite a lot of bias. When the bias was set properly for the tape the machine wouldn't erase properly. I since switched to Maxell UD and XL1 and recording was fine.
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Old 27th Nov 2011, 5:47 pm   #86
scottie_UK
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Default Re: Tandberg 2041 (series 2000) Erase Head Problem.

TDK SA35 tape is where it is worst.
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Old 27th Nov 2011, 7:26 pm   #87
DOFFERY
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Default Re: Tandberg 2041 (series 2000) Erase Head Problem.

Hi Scottie,
Check the voltage at C 307 , 35volts. then 27 volts on the collector of Q 505, see the board on page 34 of the manual.

Ricard is quite right, some tapes are very difficult to erase 100 % , I have one tape , unknown, which will neither record/erase!!

Colin.
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Old 27th Nov 2011, 8:52 pm   #88
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Default Re: Tandberg 2041 (series 2000) Erase Head Problem.

Quote:
Originally Posted by DOFFERY View Post
I have one tape , unknown, which will neither record/erase!!
Drifting away from the topic here, but I once extracted some computer grade 1/4" tape from a DC600 cartridge, it is of some high-coercivity type with low output and virtually unrecordable/uneraseble. Completely black in color, back-coated. Probably is great for recording data on where it is important to back the bits as tight as possible, but the signal to noise ratio is of secondary importance.

Don't know TDK SA35, never went with TDK for reel-to-reel, perhaps someone else here does?
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