Batboard

Is RG-8X suitable for use with a repeater? I need to make a connection from inside the house at the repeater to outside the house to the antenna. I'm using 5/8 Andrews Heliax to run to the antenna but needed something flexible enough to bring in the house to connect to the repeater. I need about 10 ft. to bring into the house... I was advised not to use LMR-400, which I have on my simplex set up, but wasn't sure what would be best for a repeater with duplexer..

What frequency/power?

I personally wouldn't use 8X. It's not 100% shielded.

We typically use RG214 for repeater-to-can connections, and heliax out to the antennas.

The frequency is 462/467 Mhz @ 50 watts.... again, the run is about 10 ft. I know that an antenna is only as good as its' weakest link and I was hoping to get good performance from the system...

I have LMR-400 but was told not to use it due to noise when used with a repeater... looking for the best... Can't seem to find any suppliers of RG-214. I've looked online and at nearby radio suppliers.. any help in directing me to a source of RG-214 would be helpful.

Have a look here http://www.davisrf.com/ham1/coax.htm

They list both 9914 "BuryFlex" and RG-214 cables. Both are 100% shielded coax. I don't have any experience with Davis RF but I've heard good things about them.

I use 1/4" super flex.

Its like hard line but very flexable.

Conectors are not real expensive and come in all flavors.

Hey, he's got LMR400 why not use it in a short jumper, lot's better than the RG8X stuff.

Just remember that LMR400 does not like to be flexed ( and was not designed to be flexed) and that is what may cause noise in a repeater.


BTW, we use LMR400 and haven't had any problems.

I don't believe RG-214 is 100% shielded. The stuff I've worked with is double shielded with two layers of braid, but that still leaves holes. Foil or some solid metal (like LMR-400) would provide 100% shielding.

Some form of super-flex coax would be best. LMR could be used if it was not in a constantly moving situation, or exposed to large temperature swings.

Bob M.

You might look at Cushcraft ULTRALINK TL93605 I have used this for short runs with good success. Here is a link to a data sheet
http://msrc.wvu.edu/lcit/EE-RF/manuf-pa ... atcom2.pdf

The 214 I've used has braid AND foil, so I'm assuming it's 100% shielded.

The Davis RF link describes all the types of coax they sell and which are 100%.

But to reiterate another poster why couldn't you use LMR400 if all it's doing is running from the duplexer to some heliax?

I just purchased some RG-214.... and I made the discision to get the RG-214 based on information from this forum on a previous discussion. I'm in the learning process of setting up my own GMRS repeater and find this site an extremely valuable source. I like being able to learn from my projects and I like doing them right the first time.

I was told,

"I hope you will not be using LMR400
on any repeaters.It is great cable on
simplex but hell for a repeater."

Another response was,

"Like Raymond said, I would NOT recommend any LMR or Cinta cable. They will create noise on your repeater due to the two shields rubbing together.

The best you're going to do without moving up to Heliax style cable is plain old RG-8 cable. It has about 3.5dB/100ft at 450MHz. If you are concerned with the price, I have some 1/2" Heliax for not much more than the RG-8 costs. "

LMR400 is fine for indoors. 214 is a good choice and does offer 100% shielding. I would go and get some RG-142 Thermax, personally. You can use RG-58 connectors with it and it is double shielded with foil. It is also smaller and less of a sore thumb than the big stuff.