jt Posted January 7, 2021 Report Share Posted January 7, 2021 I understand multiple inputs are regularly combined into one antenna system for in ear music monitors. Is it possible to combine the output of 2 Comtek base stations into one antenna? TIA. Quote Link to comment Share on other sites More sharing options...
LarryF Posted January 7, 2021 Report Share Posted January 7, 2021 Any combined transmitters need an isolator of some kind, either passive or active. If you simply connect the two transmitters together with a tee, best case is that the output of both transmitters will be greatly reduced. Worst case is that you will let the magic smoke out. Best, Larry F Quote Link to comment Share on other sites More sharing options...
Derek H Posted January 7, 2021 Report Share Posted January 7, 2021 I tried this with two Comteks. A BST-75 and a BST-50b using a mini circuits splitter in reverse to feed a phase right. It worked but I was using one of those channels to feed camera operators and they were getting some hits so I went with a different setup. It could Have been just random interference or not so random like wearing their receivers (PR75a) in close proximity to their various high powered wireless gear. There’s some loss (about 3dB I think with the two-way passive) so maybe that was the issue. Wasn’t able to nail it down in the time I had. The other combined channel was sending out to video village and no complaints there. I think it’s an idea worth exploring though and it seems like there could be some benefits. I would go for an active antenna combiner to eliminate the loss but finding one that works down to Comtek frequencies might be tricky. I always thought it’d be a good idea to try for a busy bag rig with camera hops and IFB transmitter/s to just combine the outbound RF and remote an antenna up to your shoulder or something and get it away from your receiver antennas. Maybe then you could just keep the whips on the receivers rather than a full antenna distro and see a similar range improvement. But a bag-friendly active antenna combiner doesn’t seem to exist. Quote Link to comment Share on other sites More sharing options...
Philip Perkins Posted January 7, 2021 Report Share Posted January 7, 2021 Bill Ruck figured out a passive combining setup for me for the USA units of Salvador, for 3 wireless transmitters sharing the same antenna. He made careful measurements and we made very specific cable lengths between the TX and the Ts (which fed a single mag-mount antenna out of the shots). The set up worked very well for car-to car work on that movie, as well as lot of commercials and etc jobs, so while this is not the first choice any more it can be done. Quote Link to comment Share on other sites More sharing options...
Doc Justice Posted January 8, 2021 Report Share Posted January 8, 2021 I have routinely combined 4 Comtek BST-25 base stations into a single Phase-Right or Mini Mite antenna with fine results. As long as the impedance of the cables and splitter match correctly, you likely won't be able to notice and real world differences. Quote Link to comment Share on other sites More sharing options...
Derek H Posted January 9, 2021 Report Share Posted January 9, 2021 What do you mean by as long as the impedance of the cables match the splitter? Beyond everything being 50-ohm type? Quote Link to comment Share on other sites More sharing options...
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