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Cart Machines...
- Thread starter SFM-Ptgal
- Start date
TomT said:
We had Fidelipak "Dynamax" cart machines at the TV station I worked at. They were purchased new in early 1988 to replace the old spotmaster recorder and '5-spot' play decks. (all of which subsequently found a new home at my house)
These had fast recue that was a lot faster than 15ips! The problem was that it would slightly overshoot the cue point on carts that were recorded particularly 'tight' to the head.
We also were blessed with the wonderful linear cart eraser/splice-finder! No more corduroy pant sounds from the crappy bulk eraser, and no more giant splice dropouts!
I don't think the speed is an issue.
The reason that RtoR machines lift the tape when RW and FF is to prevent unnecessary wear. There is no need for head contact so why do it.
At any time the tape is in contact with the head and there is motion there will be head (and tape) wear. At twice the speed the wear is twice as fast, but the time to hit the cue is half as long.
Yes there could be some added wear related to heat but I don't believe it is a major factor.
And since you are listening for the cue tone head contact is mandatory.
Just MHO
The reason that RtoR machines lift the tape when RW and FF is to prevent unnecessary wear. There is no need for head contact so why do it.
At any time the tape is in contact with the head and there is motion there will be head (and tape) wear. At twice the speed the wear is twice as fast, but the time to hit the cue is half as long.
Yes there could be some added wear related to heat but I don't believe it is a major factor.
And since you are listening for the cue tone head contact is mandatory.
Just MHO
RealityCheckr said:
Anyone who ever cleaned the crud off the lifters on a reel-to-reel deck (you did clean the lifters when you cleaned the heads, didn't you?) knows that not only do lifters prevent wear, they also prevent additional oxide/dirt buildup on the heads. Never mind the added benefit of protecting tweeters (and ears).
Kind Regards,
David
R
RolfTaylor
Guest
Speaking of reel to reels - how many here know what "do not slam the gate" means?
N
ncfradio
Guest
More than likely an Ampex 350 series with the manual tape lifters?
The Ampex 300 and 350's had a cover that went over the front of the heads. This cover held the tape in contact with the heads during playback, but pulled the tape away from the heads when opened. As I recall, there were little pieces of spring metal that could break if you did not handle the "gate carefully.
(Pause while I dig through a pile of stuff:
Here is a quote from the Ampex 350 manual:
"NOTE: In either fast Forward or Rewind mode, it is desirable to to remove the tape from direct contact with the heads by opening the gate of the head assembly."
(Yes I have a 350 manual. No, I don't have a 350. I do have some 5050's and Otari 1000's in the basement.)
(Pause while I dig through a pile of stuff:
Here is a quote from the Ampex 350 manual:
"NOTE: In either fast Forward or Rewind mode, it is desirable to to remove the tape from direct contact with the heads by opening the gate of the head assembly."
(Yes I have a 350 manual. No, I don't have a 350. I do have some 5050's and Otari 1000's in the basement.)
R
RolfTaylor
Guest
Yep, exactly what I was thinking of!
The metal pieces that formed the hinge and also lifted the tape were made of pot metal and would snap fairly easily.
The metal pieces that formed the hinge and also lifted the tape were made of pot metal and would snap fairly easily.
TomT said:
The 351 ampex had a stronger return spring, and was capable of throwing tape dust into the head
assembly,,,it was in the stainless steel head cover with the little black ball as the open/ close mechanism. You could hear it all over the station when a frustrated employee was splicing tape! Circa 1965...anyone remember?
assembly,,,it was in the stainless steel head cover with the little black ball as the open/ close mechanism. You could hear it all over the station when a frustrated employee was splicing tape! Circa 1965...anyone remember?
I remember having fast cue on the ITC Deltas. We had a stack of 6 and had to clean the heads often. They also seemed to run pretty hot too.
On the old Scully automation decks we were also warned never to go from FF or REW to stop (always change directions to slow it down). They never could keep the brakes adjusted properly so if you hit stop from fast wind it was possible you'd have a big mess to take care of!
On the old Scully automation decks we were also warned never to go from FF or REW to stop (always change directions to slow it down). They never could keep the brakes adjusted properly so if you hit stop from fast wind it was possible you'd have a big mess to take care of!
And lock down the Hubs on those 14" reels of tape on those Scullys. If you didn't they would go off the machine with serious forces. At WATO-AM 1290 when I was a young engineering assistant/DJ, one of the jocks didn't. The reel sailed off the Scully on the FM side (94.3 WUUU) and impaled itself in the control room wall deeply. Accompanied with the words, Oh! S***! The practice of using FF/Rewind alternated before stopping tapes is known in pro circles as "Feathering The Brakes" Kept tape from being snapped or dumped in the floor.
The cart machine head wear is reduced quite a bit because the tape is lubricated.
The tape tension on a cart machine is also much less than on a reel to reel machine.
Cart machine tape heads were designed for long life. Most machines used ferrite heads.
Back in the days, it was rarely necessary to replace a cart machine tape head ... even after many years of 24/7 service.
The tape tension on a cart machine is also much less than on a reel to reel machine.
Cart machine tape heads were designed for long life. Most machines used ferrite heads.
Back in the days, it was rarely necessary to replace a cart machine tape head ... even after many years of 24/7 service.
frankberry said:
Lubrication is a double-edged sword. If the lubrication was solid (graphite) it could eventually cause wear if enough of it accumulated in the wrong places. If it was viscuous (silicone) it could attract and hold dust particles that might cause wear.
That being said, it's worth pointing out to newbies that it was the back of the tape that was lubricated, and the lubrication did not normally contact the heads.
Magnetic cart tape was some amazing stuff. The contortions and stresses under normal cart use (twisted while being drawn from the center of the spool) were incredible, yet tapes usually had a rather long life span, often outliving the life of the cart's foam pressure pads (especially grey Fidelipacs. Woof!).
With all the restraining factors, the tape manufacturers had quite a balancing act to perform, and it's an admirable fact that carts performed as well as they did!
Kind Regards,
David
Frankberry is a wealth of knowledge on old broadcast gear. When he was up here in NC a year or so back we had a ball talking about such things as:
Magnecorders..their little knurled metal spring-loaded tape reel hold-down thingies...and the UBER-FAST rewind..you could literally slice salami with those.
Spotmaster 505's and how they would run and run and run and run forever!
Ampex 350's and the almost tank-like build quality (except for those head gates)
Scully tape decks BEFORE they added logic..would drop a reelfull on the floor even if you looked at it weird...
The old "Step Action" Gates remote control..at the studio it had a couple of military grade switches and a telephone dial. At the transmitter a big set of heavy relays..You would hit reset, and dial 1 to get the different meters to get readings..and at the transmitter there was a Fisher Space-Expander reverb unit..mounted in the same rack. Every time you took a reading you could hear the springs rumble on the air..and that is how the CE knew weather or not we were taking the readings..
Those stainless steel sleeves that went over the motor shaft on a Russco or QRK turntable that would speed the records up to 46.5 rpm because some consultant thought it made the songs sound "like they enjoy being on our station more than the competition" Then the "competition" got sleeves, and we would have to put splicing tape on ours to speed them up EVEN more!
And of course cart machines..the last ones I recall were the Pacific Recorder variety and they were really nice..but they used some kind of proprietary track configuration that made anything you "brought" from another station useless.
Too bad we're the only ones who care about this..Engineering peeves and nightmares would make a fine book..
Magnecorders..their little knurled metal spring-loaded tape reel hold-down thingies...and the UBER-FAST rewind..you could literally slice salami with those.
Spotmaster 505's and how they would run and run and run and run forever!
Ampex 350's and the almost tank-like build quality (except for those head gates)
Scully tape decks BEFORE they added logic..would drop a reelfull on the floor even if you looked at it weird...
The old "Step Action" Gates remote control..at the studio it had a couple of military grade switches and a telephone dial. At the transmitter a big set of heavy relays..You would hit reset, and dial 1 to get the different meters to get readings..and at the transmitter there was a Fisher Space-Expander reverb unit..mounted in the same rack. Every time you took a reading you could hear the springs rumble on the air..and that is how the CE knew weather or not we were taking the readings..
Those stainless steel sleeves that went over the motor shaft on a Russco or QRK turntable that would speed the records up to 46.5 rpm because some consultant thought it made the songs sound "like they enjoy being on our station more than the competition" Then the "competition" got sleeves, and we would have to put splicing tape on ours to speed them up EVEN more!
And of course cart machines..the last ones I recall were the Pacific Recorder variety and they were really nice..but they used some kind of proprietary track configuration that made anything you "brought" from another station useless.
Too bad we're the only ones who care about this..Engineering peeves and nightmares would make a fine book..
Does anybody remember the really nice MCI reel machines. We had one in the production room at WSOC. A funny thing happened one night. It's early evening and there isn't much going on. For some reason I keep hearing something that sounds like pounding but I have no idea where it's coming from! It turned out that I had left the pot up on the MCI and the monitor in the production room. The reels on the MCI were creeping very slowly making and that was making the low frequency noise I was hearing.
JH-110s. 'Jeep' Harned's gift to grcious broadcasting, and the nicest tape handling machines that were ever made - when they worked. The weak link was all the plated Molex connectors on the board and the pins on the motherboard.. eventually the plating came off and the connection got flaky. And the tension loop wantwed something like 50 microamps at normal tension. Somebody - maybe Conrad Trautman - had his assistnt take them and replace all the pins and connectors with gold plated ones and then ran them forever. Nice machines, easy to set up, and incredible audio. The reel creep was so there would be tension on the tape when it was loaded. Set one side higher than the other and they would make strange noises.
Jeep Harned's classics from MCI gave us Munches, Crunches, and Intermittents until the Red IC Sockets and every Molex connector and all of the electrolytics were changed out. Magnecord PT-6 is the all time fast wind champ. And loved eating tapes if looked at dirty. Scully 270 decks were also frightening on wind speed and better have locked down those hubs carefully lest a reel get launched and lodged in control room walls. Dangerous if you were careless.
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