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.