Lmr 400

[dmonty83]

A while back I asked if LMR 400 was ok to use with the Scantenna. You folks said that it was a good idea. Well the scantenna comes with an F-Type connector. I was just told that LMR 400 was a 50 ohm cable and the antenna connector was a 75 ohm connector and probably wouldn't work. Any ideas?

 

[hsdtech]

Just use good quality RG-6 (75ohm) coax. That is all you need.

 

[dmonty83]

...

My run is greater than 100 ft...I was told that LMR400 was better for the longer runs.

 

[hsdtech]

My run is greater than 100 ft...I was told that LMR400 was better for the longer runs.

Well so is Heliax and Hardline.
I'm just saying that for scanning all you need is good RG-6. Attenuation isn't that bad. Only on the highest frequencies, but so is everything else at the higher frequencies. There are threads after threads on this subject.
Price vs. Performance, what your main bands are for scanning, etc.
I've been scanning for over 16 years, and am also a ham. In my opinion and experience RG-6 is all you need for scanning. If your run is say over 150 feet then antenna positioning, cable routing, etc. should be changed. There are also preamps if you feel the need.
I use LMR-400, but for my ham antennas which I transmit on and where price/performance is much more than for just scanning.
Just my opinion.

 

[hsdtech]

A while back I asked if LMR 400 was ok to use with the Scantenna. You folks said that it was a good idea. Well the scantenna comes with an F-Type connector. I was just told that LMR 400 was a 50 ohm cable and the antenna connector was a 75 ohm connector and probably wouldn't work. Any ideas?

By the way, who told you this wouldn't work? They are wrong. It will. If you REALLY want to use LMR or any other 50 ohm coax all you need is an adapter to connect to the F connector on the scantenna balun.
My scantenna came with an F to BNC adapter. "F" connector, for use on 75 ohm RG-6 coax, to "BNC", a 50 ohm coax connector. That impedance mismatch is nothing to worry about.

 

[oilmillcharlie]

The adapters from F to N can be found here. See item 872.

http://www.showmecables.com/showproducts.asp?category_id=457

I used these adapters on my Scantenna wirh 50' of LMR cable with N connectors purchased here:

http://www.BizSysCon.com


Made a significant improvement over the RG-6 I was using previously, especially on 800mhz.

B.K.

 

[N_Jay]

My scantenna came with an F to BNC adapter. "F" connector, for use on 75 ohm RG-6 coax, to "BNC", a 50 ohm coax connector.

While the impedance mismatch is nothing to worry about,
are you sure it was a 50 Ohm BNC and not a 75 Ohm BNC?:roll:

 

[N_Jay]

The adapters from F to N can be found here. See item 872.

http://www.showmecables.com/showproducts.asp?category_id=457

I used these adapters on my Scantenna wirh 50' of LMR cable with N connectors purchased here:

http://www.BizSysCon.com


Made a significant improvement over the RG-6 I was using previously, especially on 800mhz.

B.K.

Wow, 2 dB!

You must really listen to marginal signals. (or the RG-6 was bad to start with)

 

[prcguy]

A good quality CATV RG-11 approaches the specs of LMR-400 and it’s 75ohm, which the Scantenna is designed for. At 900MHz, Times Microwave LMR-400 is 3.9dB/100ft and RG-11 is 4.25dB for a Commscope version and other brands may be a little better or worse. There is a whole family of F and BNC connectors that fit and the coax and connectors are CHEAP. If you were near LA,CA, I could fix you up with some and crimp the connectors for you.
prcguy

 

[buffalogoat]

For receive only, RG-6 is fine! If you are transmitting, that's when attenuation & impedance become very important.