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The cue track on the cart decks are in the center of the tape between combined tracks 1 and 2, and the combined tracks 3 and 4.

The cart decks have stacked heads. I could be wrong, but I think most reel-to-reel machines have staggered heads. Even if it worked, you will have an undesirable offset between the left and right channels by a couple of milliseconds if there was a difference in head configuration.

Also, this only works at 7.5ips. Supposedly some cart machines can be modified to run at 15ips, but mine isn't set up this way.

Anyway, I'll probably never do this again, since reassembling a cart is slow and painful.

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" "Normal" tape apparently doesn't have the necessary lubricant on it and thus won't work in carts."

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It's not only the lube, but the thickness of the tape as well as a good backcoating (not found on the cheaper tapes). Loaded and spliced exactly, a thicker mil tape will work just fine in a cart machine. Of course if you splice it off by even a half inch or so from the ideal loop size, it will jam.

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from Scott N.
So do cart machines use a standard track configuration? I'm having crazy thoughts about spooling cart tape onto reels, recording stuff on my Otari 2-track 1/4" machine, reloading the tape into the cart, and using the cart machine only to add the cue tones. Would this work?

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This could be done, though one would wonder why you'd want to?

As for how it all works (Paul covered a lot of it), cart tape only travels one way... therefore, there's no need to allot track space for the reverse trip.

The monaural configuration is much like the 2-track stereo setup you'd find on an Otari or Ampex broadcast machine. In the case of carts, the audio is recorded on one track (I think it's the top one... 50% chance of being right here!), and the cue tones are laid on the lower track. Accounting for guard bands, the head (with stacked poles) therefore uses both halves of the tape.

For broadcast stereo, the cart configuration is a little wierd, and relatively unlike reel-to-reel. Again, since the tape only travels in one direction, there's only need for 3 tracks... 2 for left & right, and the third for the cue tones. There was an effort at one time to matrix L+R / L-R on cart tapes, so as to minimize high frequency phasing problems. A company called Ramco Research tried real hard to get some market share out of this... and I think ITC may also have given it a shot. I don't think either company was very successful, and I never heard why.

Anyway... as for cue tones... you could do a monaural recording on one half of a 2-track setup, then reload the cart... and your audio would be OK. The tricky part would be getting the cue (stop) tone in exactly the right place. In the real world, there's a small time period between the start of the actual tone, the time it takes for the electronics to validate it and the mechanics to release the capstan roller, thereby stopping the tape at the beginning of the recording. This is why production people had to put a slight delay between hitting the record button and actually sending audio to the cart recorder. Even if you had a machine that would lay the 1000 hZ cue without biasing the audio track record head, you'd have to have pretty good timing to get it in the right place. In the case of secondary and tertiary signalling tones, most cart recorders were capable of laying them down in record or playback mode.

There is an issue regarding cart tape lubricant. The graphite will get all over your reel-to-reel, so if you actually do try this, be prepared to give your deck a good cleaning afterward.

A side note regarding the thumping sound with bulk erasers... I was able to get good results with just about every eraser out there. The trick for me was NOT to wiggle the cart around when pulling it away from the eraser. The circular motion was fine for getting around all parts of the cart... but moving it around a lot while separating it from the eraser seemed to be the cause of some residual noise issues I used to have.

If you guys REALLY go back aways, here's a question for you... Did any of you ever put a bulk eraser to a MaKenzie cart?????? Really??

If so... you tell your story first!

And finally, for Paul... there IS a type of cart machine (by ITC, Gates, MaCarta, Sparta[ick], ATC, etc) that DOES have an erase head on it. (Jeopardy music goes here).... what kind is it?

No pics though!

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