InterceptRadio.com Forums

Guys, I'm having trouble finding something. Can anyone recommend a product that will let multiple scanners feed into one antenna. I'd preferably like it to be full-time (i.e. no selector switch)... is this possible?

Some questions:

1. I take it a device like this would be receiving only or is transmitting possible?
2. Would I need any kind of pre-amp to boost the antenna signal before going into the switch?
3. Right now, I'm only talking concerned about VHF or higher (50mhz+)... but does this exist for HF as well(< 30mhz)?


Thanks
-Nick

you can just use a splitter, like a BNC distro block for full bandwidth. When your Rx you dont need to worry, if your going to Tx you would want a auto switch or a real switch having your Rx only equipment on the same switch as Tx might cause damage if the switch has no protection.

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If I had an antenna, I would; but I can only transmit on 160 meters.
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DE K7MHI

http://www.tti-plus.com/Cables-Connecto ... mClick=540

Top right. I use it all the time both in my car and at home. Male goes to the back of my mobile scanner, antenna to one of the females and a 3 foot male-male to the other female.
In the old days I did get some interaction between the two radios, but not with the newer scanners. I currently use a 780 and 396 together.
I don't know much about the inside of radios - OK nothing - so I'm sure someone that can measure whatever you 'inside radio' types measure and say 'no you loose 1/2 of your signal'.... Whatever, seems to work for me - DOES seem to effect 800 in a negative way.

The "Splitters" referred to above are a better way to go, as using a BNC "T" can alter the impedance in each receiver at the first stage.

Some scanners may be OK with this, but when I tried it with commercial radios programmed to scan (receive only) it made each radio quite deaf.

I have used the full bandwidth splitters you use for CATV, although I think those are set for 62-75 ohms (as opposed to 50 ohm for typical radio applications) Still, even being off impedance a bit, it worked better for me than a T.

I will have to try it with some newer scanners though, I haven't tried in a long time and it sounds like the newer scanners are more resilient.

73,
Nick
N7QOR

ScannerMaster makes Radio Shack look cheap.

Theres no need to use an overpriced multicoupler for your application.

Run some good-quality RG-6 (i.e. CommScope or Belden) with decent fittings and a cable tv splitter. This will do the job. Now I know some people will scream bloody murder over 50-ohm vs. 75-ohm however the reality is that the difference in receive performance is negligible. Been there, done that, and actually measured it. As Nick said, it works better than a "T" fitting.

Two caveats; don't transmit through it and don't expect it to work very well at HF frequencies.

I'm with Rich on this one. I use an 8 port TV cable splitter -- 5 to 1000 Mhz -- from Home depot -- $ 17.00. Works just fine -- in the Metro areas.

How does F win over BNC?

I bought cable with F connectors on one end and BNC on the other. Works great. If you live in the city -- it work just fine. If you live 50 to 75 miles away -- you might have some signal loss problems. It all depends on what your'e listening to.

Agreed... if you have 8 radios ! In best-case scenario, try not to use a splitter bigger than what you need....

2-way splitter = 3.5 db loss
4-way splitter = 8 db loss
8-way splitter = 11 db loss

Though in fairness a few dB of additional losses isn't the end of the world if you are listening to local repeaters or trunked systems.

50 % or more of the group -- most likely live in the Metro Seatle-Tacoma-Everett-Bremerton areas. Since 75% are listening to 800 Mhz trunked systems, there should be enough signal to over-come any losses. It will work for most.

Having a mismatch with impedance is not going to hurt the receiver so what ever works for you.

http://www.google.com/search?hl=en&q=re ... tnG=Search


:D

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"A well regulated breakfast, being necessary to the healthy start of the day, the right of the people to keep and eat food shall not be infringed."