Coax suggestions for external GPS antenna

Mark_WS7M

I bought a TRAM external GPS antenna I want to mount up on the roof.  I'll need to run about 50-60 feet of coax to get to where the back of the radio is to feed the GPSDO.

The TRAM has like 20 feet of RG58/U.   

Any suggestions on what best to continue the run with for another 40 feet or so?

KD0RC

Andrew Rodland

I don't think you need to worry that much, actually. If it's the TRAM GPS antenna I'm thinking of, it already has a bit more LNA gain than most pucks, and the loss on ordinary coax is still <10dB/100ft at 1500 MHz. 40 feet of hardware store RG6 shouldn't provide more than 3 or 4 dB of degradation, so that's exactly what I would buy. If it doesn't work, you didn't spend too much

Steven WA8Y

Go to Home Depot, buy a 1000 foot roll of RG6 Quad braid, for $35. RG6 (F connectors to PL 259 ) are about $4.

Mark_WS7M

Thanks Len,

That's why I asked!

Stan VA7NF

KD0RC

Good call on the RG-6!  As a ham, I always think in terms of 50 ohm coax.  For this application, the infinitely cheaper and reasonably low loss 75 ohm RG-6 makes perfect sense.
Len

Martin AA6E

Maybe it's obvious, but you might want to test your cabling on the ground before pushing for the sky. I've found that the supplied GPS antenna works pretty well when set next to a window with a fair amount of open (southern) sky. I usually track 7 sats out of 11 visible with a good lock. I have always wondered how much better an antenna like yours would work, but I'm too lazy to try one. Sky coverage is what you want, not height. 73 + GL, Martin AA6E

Mark_WS7M

HCampbell WB4IVF

Tim - W4TME

Get the quad shielded cable.  It isn't that much more.

John KB4DU

True. I use RG-6 Quad for everything except jumpers in  the shack. Good connectors are weather-resistant and easy to install. The losses on HF+6 are nearly insignificant when measured in S-units. At 6dB per S-unit, 100ft of generic RG-6 is about 1/2 S-unit, imperceptible to most uses. 

Patrick

I use LMR 195 about 25 feet.  Good for 4 to 5 db loss, with N at the antenna end and SMA at a splitter.  Divers to the Flex 6500, GPS NTP receiver and ADSB RX....antenna gain is 40 db with internal LNA.  Plenty of gain per the line, splitter and connector losses.