Antenna Combiner?

[CDS-INC]

I have 3 Motorola Spectra Radios,

1 136-174mhz
1 403-470mhz
1 806-870mhz

I use these in my shack for local monitoring.

Is there an antenna combiner that i can use?
I would like to hook them up to a Wide Band Antenna, and it would be nice to use 1 antenna instead of 3-4 antenna's,

I might be adding a low band radio soon so i can monitor 30-50mhz,

Any suggestions on Yagi Wide Band or any other wide band antennas and combiners?

 

[prcguy]

Do you wanna transmit an any of these?
prcguy

I have 3 Motorola Spectra Radios,

1 136-174mhz
1 403-470mhz
1 806-870mhz

I use these in my shack for local monitoring.

Is there an antenna combiner that i can use?
I would like to hook them up to a Wide Band Antenna, and it would be nice to use 1 antenna instead of 3-4 antenna's,

I might be adding a low band radio soon so i can monitor 30-50mhz,

Any suggestions on Yagi Wide Band or any other wide band antennas and combiners?

 

[Josh]

At least for your UHF and VHF radios, there's a device called a "diplexer", a form of duplexer, that will split an antenna line and separate the VHF and UHF frequencies from like 136-200 and 350-512 or something like that and provides the required isolation to cause no problems on RX or TX granted the antenna is either of a dual-band nature, or another diplexer is at the other end splitting the line to the two antennas.

They make a three-way model, but it's usually for 52Mhz as most of these are geared toward ham operations and are also fairly inexpensive. I haven't seen one also for 800Mhz.

-Josh

 

[thewenk]

If I understand this correctly, I'm not sure why a diplexer/triplexer would be necessary, if all you want to do is route one wideband antenna to multiple receivers. Each receiver will only receive the frequencies that it is designed for. Same idea as discussed in the sticky at the beginning of this topic on using one antenna with multiple scanners.
http://www.radioreference.com/forums/showthread.php?t=105054

I personally use the DPD Productions Omni-X wide band antenna with great success.
http://www.dpdproductions.com/page_scanner.html#omnix
This antenna is discussed in this thread.
http://www.radioreference.com/forums/showthread.php?t=94550

Dave

 

[CDS-INC]

So what should i use to hook this antenna up to all 3 Spectra Radios?
I would mostly be using this antenna to recieve with light TX,
I am prob going to go with the DPD Productions Omni-X wide band antenna

 

[Josh]

If you expect to TX will any/all of the radios, you will need a diplexer/duplexer, otherwise RF will go into the other radios potentially wrecking the receivers.

Several manufacturers make a VHF/UHF model, you may be SOL for 800Mhz because I've never seen one, but there may be VHF/UHF/900Mhz where the 900Mhz may be wide enough to cover 800Mhz also, but again I don't know.

I've used a VHF/UHF one for over a year now with great success and the loss for adding it in-line is negligeble.

 

[brandon]

www.tinlee.com may be worth checking. I had them create a Lowband - VHF/UHF - 800 MHz triplexer for me and it works very well and didn't break the bank.

 

[prcguy]

I've had a Comet MX-3000 Triplexer lying around for years that I finally checked with a network analyzer. Its rated 1.6 to 160Mhz, 350 to 500MHz and 850 to 1300MHz. It actually works fine to 174MHz on the low pass port, to at least 506MHz on the band pass port and it will go down to 806MHz fine on the high pass port. Each filter is adjustable and can be tuned to move each band around a bit if needed.
prcguy