Turtlerock Forum

I've got a box of 8 SEDCO (isolation?) transformers. They are hooked up as xformer iso/matching XLR balanced LTC IN to BNC OUT. the package is a SEDCO EP1/1A.
Can't find any Interweb info. Any good or turf them?
Cheers!

BNC out? are they audio? Maybe it's a video distribution amp?

.All passive. FXLR 3 pin in, looks like a resistive pad, xformer in, xformer out to chassis mount BNC OUT. box labeled LTC IN/out. I'm Guessing not big level handlers and probably pinched bandwidth. Probably great to be used as labled or maybe a voice channel (TB) or intercom ISO....

In the old days LTC was fed to and from video recorders via BNC.

any markings on the transformers? Hooked one up to audio?

I've packed up all my test gear. If nobody knows anything about these, it's landfill time...

From Wikipedia regarding LTC "In broadcast video situations, the LTC generator should be tied-in to house black burst, as should all devices using timecode, to ensure correct color framing and correct synchronization of all digital clocks. When synchronizing multiple clock-dependent digital devices together with video, such as digital audio recorders, the devices must be connected to a common word clock signal that is derived from the house black burst signal. This can be accomplished by using a generator that generates both black burst and video-resolved word clock, or by synchronizing the master digital device to video, and synchronizing all subsequent devices to the word clock output of the master digital device (and to LTC).

Made up of 80 bits per frame, where there may be 24, 25 or 30 frames per second, LTC timecode varies from 1920 Hz (binary zeros at 24 frames/s) to 4800 Hz (binary ones at 30 frames/s), and thus is comfortably in the middle of the audio frequency range. LTC can exist as either a balanced or unbalanced signal, and can be treated as an audio signal in regards to distribution. Like audio, LTC can be distributed by standard audio wiring, connectors, distribution amplifiers, and patchbays, and can be ground-isolated with audio transformers. It can also be distributed via 75 ohm video cable and video distribution amplifiers, although the voltage attenuation caused by using a 75 ohm system may cause the signal to drop to a level that can not be read by some equipment.

Care has to be taken with analog audio to avoid audible 'breakthrough' (aka "crosstalk") from the LTC track to the audio tracks."

This would suggest that the transformers would be audio frequency stuff but who knows at what sort of quality or bandwidth. Sedco did make audio gear for the abc and other broadcast situations and the transformers in their audio distribution gear are excellent so it's possible that these are audio grade 1:1 transformers for isolation and decoupling. are there any markings on the transformers themselves? Take a pic of the internals and maybe I can help you out.

Several decades ago I recall using Sedco transformers as line out or line isolation transformers at a radio station, they would have been 600:600 ohm trannies, good for +20dBm or more and 20-20k. But who knows if we are talking about the same model, would be worth testing them, even by ear will tell you if you're in the ball park, do an A/B.
M

Sorry for late reply,been busy.
Sedco is the old business name for Harbuch when Syntec owned them before they split off .
The transformers are Harbuch numbers now

to me LTC means "longitudinal time code"
but dont know how that refers to your transformers!

Just looking at Harbuch's list,they still do a 75 ohm to 600 ohm line drive transform er. The AT208. That's probably what you've got there. I'd keep them.

so did you keep them?