Question for multi-feeders

[Brad]

Hey guys, I'm working on setting up the split PDX feed here. Two sounds cards in one machine, both can connect successfully now. I have tried to adjust the levels to get decent audio, however I have one major lingering problem; you can hear the TWR/Gnd feed on the TRACON stream (just a bit quieter) and vice versa.

Anyone else using a single machine for multiple feeds have an answer to this one?

Brad

[PIT]

actually yes i run 4 feed on one computer. And i had the same problem, are you using one antenna for both feeds?

[Brad]

Yes, single antenna with a splitter.

[Brad]

Is there more to that PIT that is related to the single antenna? Is some special kinda of splitter or isolater needed? I have listened to both scanners on the same antenna and they both sound fine, it is only through the computer that they bleed over like that so I didn't think it had anything to so with the antenna connections. I figured it was the streaming software that just wasn't working correctly.

Brad

[PIT]

Yes i had the same problem. i tryied everything even changing computers but the only fix i came up with was having a seperate antenna for each feed.

[Brad]

Very interesting, I'll try putting the stock antennas back on both and see what happens. Thanks

[PIT]

np

[Brad]

Interestingly, I tried two machines, one scanner per machine, but shared antenna still, and have the same problem. Unfortunately the stock antennas don't get a usable signal.

[Brad]

Just out of curiousity for you antenna geniuses out there, is there any way to correct this problem? An isolating splitter of some type perhaps, or is the only solution a second antenna?

Brad

[Brad]

I believe I may have found the answer to my question:

http://www.grove-ent.com/multicouplers.html

Anyone have experience using one of the "Stridsberg MC102 Passive, 100 kHz - 500 MHz, 2 ports" devices?

[Brad]

The multi-coupler did not solve the problem, but presuming it is working, it has eliminated one possible source, so the troubleshooting continues.

Brad

[PIT]

have you tryied grounding the antenna or splitter?

[Brad]

Found the solution. Installed a ground-loop isolator on one of the audio cables (specifically the one on scanner 2). I also removed the multi-coupler and replaced it with the cheap TV splitter again with no return of the problem so it appears the problem was specifically related to isolating the audio cables.

The setup is 1 Scantenna through a cheap TV splitter into 2 Radio Shack Pro-2052 scanners both connected to 1 computer streaming both feeds. The cross-talk occurs when both scanners' audio cables are in any able to ground loop. Both connected to 1 computer, both connected to 2 computers on the same rack (with completely independent and isolated power sources), one cable connected to the computer, the other touching the computer/rack. To solve the problem, replace 1 of the audio cables with a ground-loop isolator and tada. Isolating the system's power source, using two antennas, using a multi-coupler, and using two systems with different power sources on the same rack had no effect.

Feed is up for testing now: http://www.liveatc.net/forums/index.php/topic,2541.0.html

Brad