"Dave Plowman (News)" wrote:

In article ,
Michael A. Terrell wrote:
JVC was part of a small consortium that bought the rights to Ampex's
cartridge video tape design when they decided not to enter the consumer
video tape market. IIRC, they paid a measly $10,000 for everything.

Didn't know that. If you Google on helical scan the hits I looked at
credit Ampex with inventing this in '56 - but of course the original 2"
quadruplex pro machines weren't helical scan. They had the head at right
angles to the tape and achieved head wrap with vacuum. Four heads were
needed on the drum so one was always in contact with the tape - hence the
name. This was impractical for domestic use as you need a clean supply of
compressed air. Helical scan gets round this by having the head just off
in line with the tape and records along, rather than across, the tape and
only needs two heads on the drum. The tape itself can deform enough for
good head contact so no vacuum needed.

Ampex pro helical scan - 1" C Format - machines didn't appear until the
late '60s, although others had used it for semi-pro apps before.

So I do wonder who holds the patent on helical scan? More Googling is
needed...


I would think they have expired, long ago. Open R-R 1/2" mono and
color machines were being sold by Panasonic, Shibaden and Sony by 1970
as "Industrial Video" for making training tapes and low grade
commercials. My high school got a Panasonic for the '69-'70 school year,
and only two tapes and a camera. It was to be used to time shift the
EDTV on PBS to when a teacher needed it. I had teachers demanding that
very show related to their class be recorded and archived on tape that
was $110 an hour.

The US Army was in the process of phasing out all of its 2" Ampex
machines to U-matic at Ft Rucker Alabama when I was stationed there in
'72-'73. Ever see a U-matic with a Tektronix nameplate? the military
wasn't allowed to purchase foreign made electronics, unless it was
supported by a well known US company, so the Sony machines were sold
through Tektronix.

BTW, two 2" machines and the associated equipment was in a full
length tractor trailer for remote shoots. Less than 20 years later I had
more capability in the back of the mobile production unit I built in a
standard length van for WACX in Orlando.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida