Batboard

Installing a gmrs repeater. cable run is 35 ft . Output is 35 watts..what should I use for cable? Can I use cinta 600?

Thanks

Most repeater pro's do NOT use any foil/braid types of coax. The foil/braid type cables are prone to duplex noise and passive intermod generation.

Heilax is the best.

For that distance, Andrew (CommScope) 1/4" Superflex, FSJ1-50A, should work nicely.

Too thin, easily damaged, and installers often make a hash of fitting the connectors. I recommend the 3/8" cable and check to see if a plenum or riser cable jacket is needed.

So, we use 9914 often to make a jumper between the repeater cabinet and lighting arrestors, maybe less than 10' in most cases. I have never run into the issues of noise in duplexed systems, however the runs have been short. I would also assume, since 9914 style cable is used as jumpers on many duplexers themselves, this problem is isolated to longer runs or outdoor (wind exposed) installations?

I would have no issue in using 1/2 heliax, however if it is not terminating into a fixed rack or cabinet, people moving the cable and cabinet worries me. Stressing the connectors on the hardline is much easier than a 9914 type cable.

Thanks, Rob

wow all this overbuilding of a gmrs repeater

come on guys

superflex is extremely lossy (4db/100ft at 450mhz!) and heliax is overpriced for such a project

LMR400 or LMR600 is fine for 35 feet

you can put my name on that

Thanks everyone for your input. Im going to go with the lmr 600. The cost is less than half of the heliax.
Thanks again to the forum !

Frank

escomm wrote:wow all this overbuilding of a gmrs repeater

come on guys

superflex is extremely lossy (4db/100ft at 450mhz!) and heliax is overpriced for such a project

LMR400 or LMR600 is fine for 35 feet

you can put my name on that

+1

And I see no benefit going with LMR600 for this band at this length. I'd stick to LMR400.

For a run that short, good old RG214 would be perfectly fine, and no LMR foil/braid noise worries.

wavetar wrote:For a run that short, good old RG214 would be perfectly fine, and no LMR foil/braid noise worries.

Other than the price going in the complete opposite direction, you have a point. RG214 is more expensive than heliax.. and even lossier.

And btw, if LMR400 is good enough for short runs of public safety BDA applications at 700 & 800MHz, which it is, then it's good enough for any GMRS, amateur, or even commercial repeater... that's not at an RF dense site. All this nonsense is overengineering and a separation of the user from his money

Every time I run into so called noisy lmr cable, it's the connectors. Either poor workmanship, or poor mating. I had one recently with the braid trimmed off entirely with a tiny bit of the black outer coating trapped in the crimp. This was supposedly a pre-made bagged cable from the interwebs.

Is this a good time to piss and moan about DIN connectors and AVA and other types of garbage Andrew is shoving down LMR's throat

I like how the connectors are so interchangeable between AVA5 and LDF5. Two thumbs up!!!!!!!

(/sarcasm)

Well, what's superflex good for then?!

KG4INW wrote:Well, what's superflex good for then?!

For people that can afford it, it's great for indoor cables. Some sites require it.

KG4INW wrote:Well, what's superflex good for then?!

RX jumper from a multicoupler to a receiver

I got some HFSC 12D (pretty sure that's the model code) 1/2" coax dirt cheap last month at a radio field day and it has been EXCEPTIONAL here on a 33m run for both VHF and UHF. I run from the antenna to just behind the radios where I have a 10-20cm RG58 patch to go from the N plugs terminating the 1/2" to MPL plugs for the GM300UHF/M120VHF radios. As the radios are both affixed to a shelf the coax comes up behind the shelf off the floor and the plugs sit just a few cm above the shelf some 6 or so cm from the rear of the radios.