what is this test tape?

The 4.21 IPS bothers me.

It's a cal tape of some sort. If it's not at the right speed, all the calibration levels will be thrown off. I've never heard of 4.21 IPS, so maybe it's a typo or some reference I'm not familiar with.:eek:;)
 
It also looks like there isn't very much tape on the reel. From the pic Im not sure there is any. But for 25 bucks, well at the very least you'll get a reel. :)
 
Weird!

Must be a calibration tape for a logging/data recorder or something along those lines?

Definitely not suitable for any normal audio stuff.

Cheers! :)
 
STL made a lot of different calibration tapes. This one won’t work for the MX5050-8. :( For one you need IEC equalization, not NAB. There were tons of machines back in the day that used ½” tape; most not for multi-track reel-to-reel. There were a lot of video, instrumentation and data logging machines. 4.21 ips doesn’t sound familiar. I posted a list of calibration tapes a while ago and this more recently.

https://homerecording.com/bbs/showpost.php?p=2794122&postcount=5

The following calibration tapes will work for any 1/2" 8-track 15 ips IEC machine.

TEAC YTT-1144
TEAC YTT-1144-2 (YTT-11442)
Fostex 9200
BASF 337534A
MRL 31J229

Or for the minimum necessary to set bias, operating level and azimuth:
MRL 341-673-482-103

:)
 
I thought the 4.21 IPS thing might have been a listing error...

Isn't it possible to use different EQ curves to set bias? NAB, IEC or whatever? I thought there was no right or wrong EQ curve to use, though some were preferable over others because they gave more accurate recording/reproduction.
 
Unfortunately there’s a lot of questionable info on the web. EQ curves are absolutely critical. It’s the difference between having a properly working machine and not. TASCAM, Fostex, Otari and Revox all use IEC for multi-track (8-track and higher except the 388), as do Studer, MCI, etc for 2” 24-tracks @ 15 ips. Most half-tracks use NAB in North America and some half-track machines are switchable between IEC and NAB.

If a machine does not have a switch, you need to replace several resistors and capacitors in the EQ circuit to change it. It’s not just a matter of using a different cal tape.

There is a process to adjust your measurements if using a NAB tape on an IEC machine (and vice versa) but it’s a convoluted pain in the ass and not as accurate as having the right tape.

The tape you have there is not for any half-inch open-reel used in pro/semi-pro recording. The STL model numbers for audio cal tapes start with the letter “C.” The listing says it’s a “SPECIAL A. E. I.” That could be a reference to AEI Music Network, but I’m not sure. They used proprietary tape equipment to provide music for airlines and other businesses in the 70’s.

There are hundreds of tapes for every width, speed and equalization and you have to get the correct one for your machine.

See the MRL site for info on calibration tapes and related topics.

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

It can be confusing because one reel looks like another. But at one time tape was used for everything… computers, military, industrial control systems, scientific instrumentation, including NASA, public safety data and voice logging, video, etc. There are tons of old mystery tapes on eBay that have nothing to do with pro audio.

Buyer beware.

:)
 
Thread revival here, but I'm getting the Teac cal tape from Sweetbeats. I've looked through the manuals for the 38, TSR-8 and MSR-16. The 38 specifies a YTT-1144SP IEC eq and the TSR-8 and MSR-16 both specify the YTT-11442 IEC, so the 11442 (or rather 1144 series (non sticky) can be used on the 16 track as well as the 8-tracks. *(1/2") AFAIK the MSR-16 is the only 1/2" 16 track from Teac/TASCAM. The same goes for the MRL tape: http://www.jrfmagnetics.com/mrltapes.html

As an interesting aside, I got an Ampex cal tape with an A-8 I bought which is 185nW/m (it's backcoated and says "Ampex" so likely needs to be baked.)
 
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