[TenTec] RFI into Orion II

[Jim Brown]

On Sun,2/21/2016 8:13 PM, Gary J FollettDukes HiFi wrote:
> PS: I worked for 3M Company in the field of CD replication back when there was still money in it, and worked on the development of DVD replication processes, including dual layer DVD processes, back around 1998, before DVD even became the de-facto video standard.

That's neat stuff, Gary! Back in the early '80s, I did a consulting 
project on audio for a major videocassette duplicator based in a Chicago 
suburb. I was subsequently hired to write a paper on behalf of my client 
for presentation at a SMPTE meeting on the subject. I later did a 
project for a major ad agency on the audio side of duplication of the 
broadcast video tapes that distributed their commercials to stations. 
That was quite interesting -- they called me in to evaluate a dozen or 
so tapes from several vendors, but the tapes already existed when they 
hired me. The only test tone on the tape was a mid-frequency setup tone 
(maybe 1 kHz, but not exact).

I was able to look at that tone for harmonic distortion and, by looking 
at a high resolution FFT, study wow and flutter by observing the very 
low frequency sidebands produced by the resulting modulation. And got 
frequency response by collecting 1/3 octave band peaks for the duration 
of the spots (20 seconds) and comparing copies with the master. That 
project was quite high profile in the audio studio community in Chicago, 
which led to a task force of the real engineers in each studio to 
develop a "White Paper" defining setup tones that would go at the head 
of every reel. That's 30+ years ago, but as I recall, it included pink 
noise, a setup tone to do the sort of things I did with it, and even a 
clipped tone to identify polarity of the waveform.

73, Jim K9YC