This is the Ampex TV Equipment Section of
The Broadcast Archive
Barry Mishkind - The Eclectic Engineer
With the kind assistance of Xen Scott
Latest Update 2/28/04
Xen Scott recalls: "The VR-3000 was a special
purpose machine that was designed for field recording where the use of a full
size videotape machine was impossible or undesirable. A portable, two-inch
quad-head VTR, it was built into a suitcase, used 20 minute reels and was
capable of high-band recording. It could be battery powered or operated on AC.
"The VR-3000 was a very unusual machine. It's not easy to
compress a two inch quad head videotape machine into a suitcase so it could be
carried while recording and powered from batteries when desired. Fortunately, I
never had to carry the 55 pound VR-3000 while in operation. The VR-3000 could
record in high-band or selected low-band standards using two-inch videotape on
20 minute reels. The recorded tapes would play on any two-inch, four head
videotape machine. Video playback from the VR-3000 was from the demodulator
output with no timebase correction, so VR-3000 playbacks were only good for
monitoring and confirming that a recording had been made.
"The VR-3000 had no erase capability. All recording had
to be done on blank tape. Most of the forward tape motion was provided by the
takeup reel. The rubberized capstan, without a pinch roller, was used for
maintaining correct speed within the range developed by the reel servos. The
tensioning force delivered by the reel servos was controlled by strain gauges
mounted on small tension arms in the tape path. Early model VR-3000's used
resistive strain gauges. They were temperature sensitive and this resulted in
severe tape speed errors when the ambient temperature was different than room
temperature. Later model VR-3000's used capacitive strain gauges which were not
sensitive to temperature. The special video record head used ball bearings in
place of the air bearings found on video head assemblies used on full size
videotape machines such as the VR-2000. Vacuum for the video head tape guide was
provided by a built-in miniature vacuum pump."
Lytle Hoover notes: "An interesting sidebar to the
portable VR3000 story, from our market research at RCA, we found the biggest
user of the VR3000 was the US Navy. They had them on the aircraft carriers to do
video documentation of the planes landing. A camera/VTR crew sat on the end of
the flight deck recording the approaches and followed the plane down to the deck
until it stopped.
"I promoted this portable VTR concept to the RCA
management when I learned about our TPR-10 in the Government engineering labs at
Bldg. 13. The RCA TPR-10 had been designed by the RCA Government engineering
staff to only be a data intrumentation recorder using a quad VTR recorder
headwheel(or alternate 8 head). Our B/C engineers helped do a redesign the
TPR-10 to become a commercial TV video recorder."
If you have any old photos of Ampex equipment that operated at your TV
facility which you would like to have in our Virtual Museum, please send
them along, so we might add them to these pages.