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Joined: 31/12/2012
Location: New ZealandPosts: 9440
| Posted: 12:09am 16 Jun 2024 |
I've been playing with this a bit today, and we might be dead in the water.
As soon as I simulate the phone-line resistance IN ANY WAY, the RX end of the link refuses to then start the VCR. I'm down to LESS then 100-ohms of inserted series resistance at this point(82-ohms, 1W carbon), and the VCR never starts. This resistor is ONLY to see if I get start-up at the other end. I'm not leaving it there, even if the VCR DID start, as I would cook the 1W resistor pretty fast I think!
You can HEAR the VCR TRYING to start, but it never starts, so this might have killed this idea on the bench before I even try to test it on-site.
Does anyone have any ideas of other things I could perhaps try on this idea, before I declare it a no-go?
Basically, the phone-pair DC resistance is going to be WAY more then 100-ohms, even on the short runs. Phones don't care about that, but this concept looks like it will.
I wonder if some caps placed on either side of the RX transformer could help to just get things started?
Seemed like such a nice idea, and perfect use for the old mostly-redundant grease-filled telephone cables! Oh well....
I might still be able to use these cables and the LV AC concept, but I would probably have to hack the amplifiers so I can tap into the LV side of the SMPSU inside them - perhaps also just outright disconnecting the internal SMPSU and having a local LV regulator fed from the LC AC on the phone cables. That'll be my next experiment.
Edited 2024-06-16 10:14 by Grogster