[BC] question for you engineers

[Tom]

TV delay via quads - Yep; possible... and done a few times locally, as 
well.  The engineer who'd done it (the program had long before been 
canceled for other reasons) told me the secret was to reverse feed the 
tape across the empty take-up reel on the record machine and the empty 
supply reel on the playback machine, so the tension servos had something 
to operate against and wouldn't trip the tape-break logic.  These were 
Ampex VTRs - IIRC, model 10?  It's been quite a while.    I've heard of, 
not directly, it also being done with RCA TR-5s... although, again - I 
got the TR-5s third-hand, so YMMV...

Keeping the tensioning correct would be the biggest headache; quad does 
(did) NOT like uneven tension - I've seen too many headwheels chewed up 
by improper tension - although the scale said the tension was within spec! 

Tom S.

Jeffrey Kopp wrote:
>
>
> Further digression: I remember being told in about 1970 by our local
> public station's engineers that they'd attempted a video delay by
> stretching 2" tape between a pair of adjacent Ampex quads, presumably
> for the call-in shows they aired occasionally, but had found it 
> impractical.
> (They bravely soldiered on without by careful call screening.) I'd bet
> some station did it, though.