50 ohm Heliax OK for DBS?

[dlsnyder]

I have the opportunity to use an abandoned 40' run of 50 ohm Heliax up to the roof of a building. To save me the trouble of pulling a new run of RG6 in to replace it would there be any problems with the impedance mismatch when used with a DBS dish?

Thanks in advance...

Dirk

[boba]

PULL the RG-6 cable!!!!

[firephoto]

If they got the heliax up there then the rg-6 should be a breeze to install. lol
The mismatch with the 50 ohm cable would be a bad thing.

[Chris Blount]

I personally wouldn't mess with old cable. Why not just use the Heliax to pull the RG-6? Tie the new cable to the end of the Heliax and pull away. Shouldn't take no time at all unless the cable makes a lot of twists and turns.

[Mike500]

I'd agree. First, I'd find the end of the cables and tug on each end. If it moves, you can pull a new one through with the old one. A lot of electricians use Romex staples lightky driven just to position the cable, without holding it from being pulled through. When I prewire low voltage wiring , I often use this method.

[waydwolf]

Originally posted by dlsnyder
I have the opportunity to use an abandoned 40' run of 50 ohm Heliax up to the roof of a building. To save me the trouble of pulling a new run of RG6 in to replace it would there be any problems with the impedance mismatch when used with a DBS dish?

Thanks in advance...

Dirk

 :lol:

    Not laughing at you Dirk, just giggling at how quickly after I mentioned it in another thread that someone brings up Heliax. A pointer to an eBay auction for RG-11 "monster coax" jumpers with gold fittings can't be too far behind and I'm tempted to build a waveguide and feedhorn to send pure sat RF to a remote LNBF for the head shaking "why'd he do that?" effect.

    Yes, it would have problems and unless you want to pay the premium prices to an Andrew distributor, and figure out a way to mate their fittings to the F-81 threads you're more commonly familiar with as well as match impedance at both ends, it's pointless to do anything but sell the Heliax on eBay or somesuch.

    www.andrew.com (http://www.andrew.com) is where you can check out the wonderful and not inexpensive world of Heliax.

    Running copper-coated steel messengered RG-6 would be better for a long vertical run, with the messenger bearing the tensile stress.

 

[dlsnyder]

Thanks for the advice guys. I guess I'll be pulling through some new RG-6 after all. The conduit is on the small side and very full so I was hoping that the mismatch was going to be small enough to not make a big difference.

Waydwolf - yes I read your post and that's what got me thinking about it! All the hardware is in place - the line had been used on a base station for an 800 mhz mobile data system that was removed about 4-5 years ago.