Magna-Tech 600 film recorder
Posted 19 May 2007 - 03:48 PM
Posted 22 May 2007 - 01:40 AM
Posted 22 May 2007 - 11:18 PM
Edited by James Steven Beverly, 22 May 2007 - 11:20 PM.
Posted 26 May 2007 - 09:02 AM
Aligning any magnetic tape recorder is about the same procedure. Back in the day when I maintained all sort of reel-to-reels and broadcast cart machines the general practice was to have a test tape and:
1. Check mechanical performance, feed and pick-up torque, speed, etc. The torque numbers for a 1" non-sprocketed machine will be pretty close to what's good on a 35mm sprocketed recorder.
2. Set head height and Azimuth. If there's a wear track on the heads set height to run the tape in the existing groove. A bit of visible wear is not fatal, the record and playback gaps are pretty deep to allow for wear.
3. Set Bias (general rule is to overbias 1dB at 1kHz).
4. Check frequency response and touch-up if necessary. There's an interaction between bias and high frequency response, reducing bias at bit increases HF's.
If you don't have an alignment tape, and can't find one, ask a lab that uses an alignment tape to record a 10kHz tone with one of their properly aligned machines and use it as a second generation alignment tape. That's much better than nothing. A real friendly lab might even record some tones for you - if you have 100Hz, 1kHz, and 10kHz you can do a pretty good job of eq'ing most recorders - a full set of tones is best but those three frequencies will get you very close on 95% of the machines out there.