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Author Topic: Any large format VTR fans out there? I need some help.. Leo Enticknap Film God Posts: 7474 From: Loma Linda, CA Registered: Jul 2000 posted 04-11-2003 04:26 AM                        ...and so would hundreds of moving image archives. The BBC, for example, estimates that it has some 400,000 hours of quadruplex tape in its collection, but only about 30,000 head hours remaining on the machines it has.  |  IP: Logged John Pytlak Film God Posts: 9987 From: Rochester, NY 14650-1922 Registered: Jan 2000 posted 04-11-2003 07:43 AM                        Are refurbished heads for 2-inch quad recorders still available? VTR head supplier Spin Physics in San Diego used to be a Kodak subsidiary. Who makes/refurbishes video tape heads today?  |  IP: Logged Stephen Furley Film God Posts: 3059 From: Coulsdon, Croydon, England Registered: May 2002 posted 04-11-2003 07:51 AM                     Site with lots of Quad machines.  |  IP: Logged Phil Hill I love my cootie bug Posts: 7595 From: Hollywood, CA USA Registered: Mar 2000 posted 04-11-2003 03:52 PM                  Stephen, WOW! What a great site! Thanks for the tip! I'm still breathing hard from my visit! The machine I was thinking about was the TR-4. The TR-5 pic has a TK-60 camera with it. A friend of mine had a TR-2 ...never knew the model number, but I sure remember all them thar tubes! Thanks again! >>> Phil  |  IP: Logged Mark Ogden Jedi Master Film Handler Posts: 943 From: Little Falls, N.J. Registered: Jun 99 posted 04-11-2003 06:37 PM                     -------- Are refurbished heads for 2-inch quad recorders still available? VTR head supplier Spin Physics in San Diego used to be a Kodak subsidiary. Who makes/refurbishes video tape heads today? -------- AheadTek Electronics out of San Jose CA. still carries Ampex Quad panels from the Mark X on up, along with just about any kind of video recording head you can think of (but you have to buy new 'cause they don't relap old panels). . . www.drs-ahead.com  |  IP: Logged Bernard Tonks Jedi Master Film Handler Posts: 619 From: Cranleigh, Surrey, England Registered: Apr 2001 posted 04-11-2003 07:12 PM                     When I was on a training course, Ampex 2" Quad was included. My favourite operational machine was 1" C format. Thanks for that interesting link Stephen. A company in London supply all types of video heads.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 04-11-2003 07:12 PM                     We used to have all the Quad head panels re-done by Spin Physics. We rarely lost any on the Ampex's as they had sophisticated vacuum gap servos that would prevent very much head damage. The RCA TR-22's were another story all together though...totally manual vacuum gap servos on those, and we went through quite a few panels. One or two of the heads usually literally broke off on those dudes. The TR-22's were originally low band monochrome, that were then converted to high band monochrome, and then to high band color. Glad that was all done when I got there! I don't remember what rebuilt panels cost back in the late 70's early 80's but it was ALOT, perhaps as high as 10 to 15K per panel. I remember the Chief always cried when one went...or when a Klystron went in the TTU-110. The transmitter we ran was a whole other VERY AMAZING story. If anyone's interested I'll tell it, but if no one is I won't bother...... Mark  |  IP: Logged Bruce McGee Phenomenal Film Handler Posts: 1776 From: Asheville, NC USA... Nowhere in Particular. Registered: Aug 1999 posted 04-11-2003 08:00 PM                     Mark: I love Klystron stories! Just throw a little film on it to keep me interested... I saw a bird fly into the aural transmitter at a big UHF station in Nashville, TN. when I worked there. POW! Feathers everywhere! Is Eimac still in business? We bought klystrons from them waay-back-when.. I think Luciano may have hit something when he pulled the panels off his U-matic Sony. Maybe he has some pinched wires, or maybe a ground issue? I had a similar problem with a SL-900HF Beta machine when I got it. Would do some functions, then stop. Turned out there was a single wire that had rubbed on the chassis. Was a monster to troubleshoot. Every time I would open it up, it would work perfectly. Thought this might help...  |  IP: Logged Luciano Brigite Master Film Handler Posts: 277 From: Sao Paulo, SP, Brazil Registered: Jan 2002 posted 04-11-2003 08:45 PM                     I don't know for sure what happened, I had pulled out the front control panel then removed the front cover of it.everything stayed the same after that, already had checked all the wiring for misplaced conectors and broken/damaged wires and everything was ok.I was checking the signals on the control panel ( the one with the buttons) with my scope when things got @%¨$% *¨&&$$@ even more. all of it's boards have those lousy smd devices on both sides and some have htose IC's with zillion terminals all around it. I think devices like that should be prohibited. they're the biggest IMO... dunno.. maybe I touched the board I was holding on the other still in the machine.. or something there didn't like being probed by my scope.. I'm waiting for a reply from a company that has the VO6800 service manual for sale.. the $65 will be a damm kick in my rear end but I'm not giving up on this vt very ez.. just hope the dude reply my email.. and about tquad's machines.. while looking for the manual here wher I live, was talking to someone that worded for a production company , he said that one company he knows a lot of ppl there, had about 3~4 quad machines and they no longer uses them. hte curious thing.. the production company has 2 studios that were put up in a place that originally was.. a twin movie theatre.. and acording to him.. those quads are laying somewhere in the basement of these studios.. now.. wish I'd put my hands on them.. but they won't throw them away for sure nor sell any for cheap.. also don't know anyone in that prod. company.. even if i'd get any of them... I think that quad tapes are no longer made.. atleast I never saw any of them for sale,brand new in any places I knwo that deals with pro tapes.. for now I wanna bring my U-matic back to life.  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 04-11-2003 11:07 PM                     The Channel 38 transmitter is an interesting story but I'll tellan abbreviated story of it....I don't recall any birds ever getting in the 94th floor where the transmitter was but that would have been an interesting happenning..... It was an RCA TTU-110 100kw UHF transmitter that was atop the Hancock building in Chicago. It was originally supposed to be WCFL TV. That was the Chicago Federation Of Labor, and their call letters. The FCC gave them permission to construct the site and a liscense to operate but then revoked it because they were a labor union. So the site sat and sat for around 7 or 8 years. Then a start up religeous station was looking for a broadcast site, and transmitter, and bought the WCFL xmitter equipment for a rediclous sum of either $1.00, or $100.00...can't remember which amount but doesn't matter....WAY TOO CHEAP! Anyway I worked there 2nd shift in engineering and worked with the transmitter engineer on Sunday nights from 12 midnight to 6am...the only time period we were off the air at all during the week. Aside from probably being the cheapest bought 100kw UHF transmitter it was also the very first transmitter that had a pulser installed. It was an add on kit from RCA and was a looooong time in the designing...and installation. Basically it limited the sync pulse power transmitted to conserve power usasge of which this thing used gobs of. 1200 amp 3 phase feed! Typical electric bills ran anyplace from 19K to 23K a month! With the pulser installed on it that bill dropped to a maximum of 14K a month and the pulser addition was paid for in less than a year. There were many problems with the transmitter, including fires breaking out in the high voltage rectifier cubicals. RCA used potted series high voltage rectifiers that failed and when they failed they caught fire.....So all 6 cubicles, which together developed 18kv at almost 20 amps were totally stripped of the RCA potted rectifiers and rebuilt one cubicle at a time with seperate rectifiers in series mounted on studs on special HV dilectric material. This cured the rectifier failures and I don't think another ever went bad. Other problems we had were water leaks in the klystron plumbing and such and that was always on the mend. The Klystrons do vibrate a bit and the plumbing expands and contracts, so leaks did occasionally develope around the 18kv high voltage. The transmitter would automatically shut down and had dozens of water sensors to detect leaks at crucial points in the transmitter cubicle itself. A major leak would instantly take you off the air. We had a number of Klystron failures mainly fomr lightning strikes rto the transmission towers on the Hancock building which were around 100 stories up. Every time you get a dose of lightning inside the tube it erodes part of the graphite comtrol grid away...after a few serious strikes you have little left of the grid and no operating tube. The tubes were rebuilt and shipped in a special casket looking case. They went back to Varian here in Salt Lake City to be rebuilt for well over 100K per tube back then...as far as I know they are still rebuilt here. The Varian factory is still here, out by the airport. Interestingly the original aurl klystron which came with the transmitter was the one still in use when I left the station. We ran it at 2/3 rated power as aurl signals carry farther than visual do. For some reason lightning strikes never affected that tube. I'll try to dig out some pics of the place and post em here. There are more stories about this place but this is enough to give one an idea of some the headaches and expenses involved. Mark  |  IP: Logged Luciano Brigite Master Film Handler Posts: 277 From: Sao Paulo, SP, Brazil Registered: Jan 2002 posted 04-12-2003 11:59 AM                     Leaky water plumbing around a 18KV spot ? Didn't know that transmitters also used water-cooled tubes, only heard of the air cooled ones .  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 04-12-2003 06:55 PM                     Well, we put in de-ionized/distilled water and got steam back out. The condensers for this transmitter...one for each Klystron....were the size of a large School Bus and located one floor above the transmitter room! That turned the steam back into water again and cooled it down somewhat. There was also some water loss....some from all the leaks, and some from normal loss so we ran our own still to make the cooling water. I knew other engineers from other transmitter sites, Chan 44 for instance, that ran the same RCA Transmitter and had the same leaky problems. I'm pretty sure though that we had the only poorly designed High Voltage rectifier stacks as this TTU-110 was the first one that RCA built....1964 vintage. Mark  |  IP: Logged Luciano Brigite Master Film Handler Posts: 277 From: Sao Paulo, SP, Brazil Registered: Jan 2002 posted 04-13-2003 12:01 AM                     The idea of leaky water connections and 18Kv near eachother is still scary for me... The transmiter itself isn't really interesting to be.. but what's inside is.. some transmitter tubes have a nice look.. The lamp I have next my bed was made with a Philips TB4/1250 tube and the aluminium core taken from the reel of a 1" tape.. already had some friends wanting it. Maybe I'll make another one when I find ( if I still have it) an Eimac 3CX2500A3 and the mech parts from my VO6800 in case I can't fix it  |  IP: Logged

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