Sticky Shed MRL Tape?!?

A

avieth

New member
After weeks of waiting my MRL calibration tape has finally arrived!
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I threaded up my R8, and began adjusting the REP CAL setting. About halfway through the ritual I noticed this:
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The tape seems to be shedding worse than my Ampex 457 tapes. Has anyone else experienced this with a new MRL tape? Could my machine be causing this?
 
Is this tape 'new' as in the current batches sold by MRL or is this a 'new old stock'?
 
Bought it from an eBay seller by the name of audiovlg. Claims to be a licensed MRL dealer and has a very impressive feedback history.

From the auction:

MRL 1/4" NEW proaudio test tape FREE WORLDWIDE SHIPPING

We are an authorized dealer for Magnetic Reference Labs (MRL), and offer their full line of studio alignment tapes for setting up analog tape recorders. These exclusive short test tapes are new, recorded full track by MRL, and contain all the tones you need to set up reproduce EQ, head alignment and reference levels.

So I am assuming this is new tape.
 
Does it have a little color dot on the spine of the box? It's about the size of an emoticon (hopefully not the one with the tongue sticking out). Let us know what color.

The tones were recorded in 2008, but the tape MRL used could be older... or it could be RMGI shedding or a bad batch of late manufacture Quantegy.

Looks like RMGI shed to me.

:)
 
The only dot I can see on the box is a black one. About the size of a bullet point. Right infront of the the url www.mrltapes.com on the back of the box.

There are a few inch long sections on the leader tape that show a pattern resembling the one on the side of these spools, but in black and white. One of these sections is shown at the top of the first image I posted ^

3M-Scotch-908-ATG-Gold-Tape.jpg


Isn't this characteristic of 3M Scotch tape?
 
avieth said:
The only dot I can see on the box is a black one. About the size of a bullet point. Right infront of the the url www.mrltapes.com on the back of the box.

There are a few inch long sections on the leader tape that show a pattern resembling the one on the side of these spools, but in black and white. One of these sections is shown at the top of the first image I posted ^

3M-Scotch-908-ATG-Gold-Tape.jpg


Isn't this characteristic of 3M Scotch tape?
Click to expand...

Make sure it's a black sticker and not a printed dot. Black indicates AGFA 366, which I've never even heard of. It could be a typo... maybe it's 368, which is a 1-mil version of 468. Look on the backcoating on the tape and see if it has the number 366 or 368 printed along the entire length of the tape (well, don't actually check the entire length... a few feet is fine.)

The Scotch style leader tape is now owned by Quantegy, but is used by everyone for different brands of tape.

By the way, I can't find that calibration tape model number at the MRL site or in old archived pdf docs from MRL going back several years. I know they make custom tapes. It's got me stumped.
:confused:
 
According to the seller, this is the short (3 minute) version of 21J303. The black dot I told you about is not a separate sticker, but is the only dot on the box. There are no text or numbers on the back of the leader tape.

I've contacted the seller, linking to the pictures of all the shedding and asking about returning the tape. Still, I've decided to make a few adjustments to my machine while I have the tape. I want to get back to recording, and waiting around for the mail is no fun.

I began by adjusting the azimuth on the play/record head. I set it in phase for 1KHz, but when the 10KHz tone plays, the oscilloscope shows an elipse. Should I be adjusting the azimuth for a 1KHz signal? My service manual doesn't exactly specify.
 
avieth said:
According to the seller, this is the short (3 minute) version of 21J303. The black dot I told you about is not a separate sticker, but is the only dot on the box. There are no text or numbers on the back of the leader tape.

I've contacted the seller, linking to the pictures of all the shedding and asking about returning the tape. Still, I've decided to make a few adjustments to my machine while I have the tape. I want to get back to recording, and waiting around for the mail is no fun.

I began by adjusting the azimuth on the play/record head. I set it in phase for 1KHz, but when the 10KHz tone plays, the oscilloscope shows an elipse. Should I be adjusting the azimuth for a 1KHz signal? My service manual doesn't exactly specify.
Click to expand...

Yeah, I was just going to say the 21J303 is nearly identical to the Fostex 9100A calibration tape that was originally made for the Fostex Model 80 and R8.

Nonetheless the tape you have is shedding like hell, so I would hold off until you get a stable tape. The problem is that you can't count on the consistency of the oxide across the tracks to get an accurate phase picture.

For phase I start with 8kHz or 10kHz and then fine tune with 16 kHz, but again, I wouldn't hang your hat on that shedding tape.

Ordering direct from MRL or JRF is your best bet.

http://home.flash.net/~mrltapes/

http://www.jrfmagnetics.com/mrltapes.html

:)
 
Beck said:
Looks like RMGI shed to me.
Click to expand...


On the azimuth you need to start at a low frequency and work your way up. The higher the frequency, the shorter the sine wave will be, so the azimuth adjustment will be smaller. start with a low frequency and do a broad adjustment, then a smaller frequency for the fine tuning. then go back and check the low frequency again and make sure you didn't mess up the overall picture.
 
FALKEN said:
On the azimuth you need to start at a low frequency and work your way up. The higher the frequency, the shorter the sine wave will be, so the azimuth adjustment will be smaller. start with a low frequency and do a broad adjustment, then a smaller frequency for the fine tuning. then go back and check the low frequency again and make sure you didn't mess up the overall picture.
Click to expand...

Yeah, that's a good point. I use a mid frequency (8kHz) to start and then fine-tune with 16kHz, but my machines are well maintained… nothing will be far off. No surprises. On the TEAC cal tapes 8k is for coarse setting and 16k is for fine setting.

But if you buy a used machine and have no idea how out of whack it might be mechanically, starting with 1kHz or 2kHz isn't a bad idea

:)
 
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