I took a look at eBay to see at what price one could be had for. There's a couple of players, but no recorders. A few boxes of carts. With the upsurge in inexpensive digital audio storage (and the simplicity with which I can personally inexpensively replace racks and racks of carts and dozens of heavy players on my iBook) I thought there would be a flood of surplused hardware out on the market. But there isn't. On the other hand, the broadcast supply vendors I can find on the web don't list the things anymore. I can only imagine that the existing hardware base is being kept within the industry for radio stations that can't or won't switch to digital media, and for spare parts.
For those that aren't familiar, the "cart deck" is a 1/4" cartridge tape machine similar to the old 8-track. Instead of recording 8 tracks, it has only two, for the two stereo channels. Each track uses half (instead of 1/8th) of the width of the tape, so the recording bandwidth, and thus the sound quality, is far better than consumer equipment. Just like the 8-track, it's an endless tape loop. You can't rewind it, you can only fast-forward.
Carts were the workhorse of broadcast radio. Advertisements ("promos" or "spots",) news report sound bites ("actualities",) station identifications, public service announcements, sound effects, anything you could think of was recorded on them. A studio in a well-financed station would have a dozen or more playback decks. Your average disc jockey was probably more of a cart jockey, constantly swapping out played carts for what he needed next. The decks are big, heavy, and bulky, but they're built to run almost constantly. The parts pop out quickly for service and routine maintenance. They had to be dependable, since your entire operation was running on them. Most stations had turntables for playing records on (and later CD players,) but some, especially Top 40 stations with very limited playlists, might record all their music for broadcast on carts. Carts could come in any length you liked. Ten, twenty, thirty seconds. One, two, three, four and a half minutes. Twenty or even thirty minutes. You were only limited by how much tape could fit on the cartridge's reel.
Of course, when you're done playing a cart, since you can't rewind it, you had to fast-forward it all the way to the beginning. Many stations had policies that their engineers or broadcast talent damned well better hit the "cue" button when they're done, lest they fuck up the next guy's life. Using tones you could record onto carts ("secondary" or "tertiary" tones,) it was even possible to enforce that requirement in the hardware, by wiring the playback deck to go into fast-forward mode when it detected one of those tones.
My first exposure to these beasts was my freshman year of high school. Our radio studio was appropriately equipped, with a Fidelicart/Dynamax CTR-11 playback deck (the left of the two pictured on Jim Price's page) and a Broadcast Electronics record deck (Similar to this one, but the same width as the Dynamax units.) Damned near everything we did for broadcast, except for music, went on cart. PSAs, promos, background music, bits, station IDs. Since we were still broadcasting from the Midwestern Academy's studio (the remote studios at GBN and GBS were still a dream) in Glenview, the 6pm DJ lugged a huge duffle bag ("The Bag") full of carts and LPs in, and the 10pm guy was tasked to bring it back to school in the morning.
(The WMWA-FM studios had the stereo version of the Audiocord E50R that Jim Price pictures. The new remote-broadcast studios built at GBN and GBS got stereo Dynamax units. One recorder, and one (GBN) or two (GBS) players.)
I always wanted to buy one, so I could do production work at home, but they were expensive. A mono playback unit would cost you at least two grand, and a stereo record unit would be nearly $5000. The thought occurred to me again tonight, hence I went looking. Looks like that's not going to happen anyways...