Duplexer Questions

[JoshuaHufford]

Going to be doing an antenna install at a friends house soon and I want to make sure I'm going to do this correctly.

I want to combine 2 antennas, one for 160MHz and one for 900Mhz into one coax, then split it again to go to 2 radios.

I already own one Duplexer a Comet CF-416W, specs are on this page.

Duplexers | Comet Antenna

wireless mobile and fixed station voice and data

cometantenna.com

If I get a second of these units, will this work to combine the signal into one coax, then split again to 2 radios? I know 2 coax runs would probably be simpler but the homeowner only wants one point of entry into his home.

What would be a good enclosure for the duplexer that will be at the antennas?

I also thought of possibly using a wide band preamp and power divider instead of the second duplexer at the radios. Thoughts?

 

[prcguy]

The Comet CF-416W will not work for your application, it has too much loss at 900MHz. They make other diplexers like the Diamond MX37 series that will separate a 1.6 to 470MHz antenna and 900 to 1300MHz antenna with reasonable loss. You can use two in series to separate the signals again but your loss will double.

Depending on your area a wide band preamp may not work unless you get a really high level unit which costs some $$. You would also want to put the preamp near the antenna for best results and use band pass/band stop filters to help keep it from getting spanked by nearby out of band signals.

 

[JoshuaHufford]

The specs on the Duplexer say .25-.3 dB loss from 400-1400MHz. Am I missing something?

 

[vince48]

prcguy,
what about 700 and 800 mhz frequencies, will the duplexer not pass them? Also, is the duplexer mounted indoors or outside the house? Thanks again for all your help.

 

[prcguy]

Looks like the "w" version will pass the freqs you need but most of the 416 series will not. You have an unusual requirement only needing to separate some VHF and some 700-900 where that diplexer should work fine. Most people want to pass up to 512MHz on one port then 700MHz on up on the other port and choices are slim there.

For outdoor use Home Depot has some small plastic NEMA boxes that are affordable made by Cantex or Carlon.

prcguy,
what about 700 and 800 mhz frequencies, will the duplexer not pass them? Also, is the duplexer mounted indoors or outside the house? Thanks again for all your help.

 

[vince48]

thank you my good friend