uh oh.

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antispatula

antispatula

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Ok, so no this is not another calibration question :rolleyes:, but I did discover the problem whilst adjusting the repro hi freq. level. I noticed when I played back the 10kHz tone off my MRL, after adjusting each level, they were all stable and at 0 VU, except for channel 8. The meter on 8 is all fluttery and unstable, but ONLY when reproducing the 100 kHz tone. On 1kHz, and 100 Hz it was perfectly fine, when I bypassed the repro head and just sent a 1 khz, and even a 10khz to the VU's using an Oscillator, it was fine. So it's ONLY messed up when I send a 10kHz tone through the repro head.......I can't get a stable reading, it's just flutters around 0 Vu, sometimes going above and below, as if it's spazing out.....

So anyone have any suggestions of what I should try doing? Should I disconnect the channels card from the terminals and just try disconnecting then recornnecting it back in? I don't know, I'm not too good with figuring out electronics stuff.....Any generall advice would be great though, thanks!
 
no that would mean buying another tape.....Something I don't have the money for yet. But if one track was off, all the others would too though, right?
 
That symptom usually points to the issue of head-wear,...

although it could also be marginal alignment of the azimuth,... which should be checked.

I'd recommend making 110% sure that the heads are as spotlessly clean as possible, and then test again. A dirty head could also cause this "fluttering" sound, in certain cases. :eek:
 
hey thanks dave, I did that, along with demagging the heads (I'll touch on that in a second.) And it helped!! I think.......I got the level to stay more stable at 0 db. But then when I came back to it, it had gone down about 2 db.....And I fixed it again. Hopefully that won't ahppen again. I'll clean the heads again though.

Anyways, I demmaged the heads too, and the tape path. I accidentally had the machine on! Man, that's the stupidest mistake I've ever made. Here's what happened:

I turned the demagger on 6 feet away. I came at the heads slowly, and when I was about 1-1.5 feet away, I realized that the machine was on! :eek: It was in ALL REPRODUCE. When I realized this, I slowly backed off and turned off the demagger, then I demmaged the machine correctly.......Then I played back a MRL tape to see if I had messed up my machine when I had the demmager near the machine while it was on. All levels were good. Then I played back stuff I had previously recorded, and then recorded a few seconds and played it back. It all seemed to sound fine.......

So do you think what I did may have done anything to the machine? I mean, I didn't get closer than like 1-1.5 feet away from the heads, and it was set to REPRO if that makes any difference. IS there anyway to check besides just listening?
 
antispatula said:
So do you think what I did may have done anything to the machine? I mean, I didn't get closer than like 1-1.5 feet away from the heads, and it was set to REPRO if that makes any difference. IS there anyway to check besides just listening?
Click to expand...
I think the problem happens if you actually bring the demag right up against the heads while it's on. That, so I'm told will, cook the reproduce amplifiers as they get about 10'000 times as much magnetic energy as they were designed to handle. The symptoms usually are that all the channels are dead.
It's possible you may need to recalibrate the repro amps and meters if they were marginally overloaded, but you would probably have heard the VU meters click against the stops if you were near enough for that to happen.
 
hey thanks for the help. Yeah, I checked all the repro levels, they are all perfect. Except channel 8 is been misbehaving lately...... :rolleyes:
 
You may want to check the bias and bias traps on chennel 8. If the traps are out it can do some wierd stuff
 
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