PSN-L Email List Message
Subject: Re: trouble shooting GPS antenna
From: Stephen & Kathy skmort@..........
Date: Thu, 10 Jan 2002 11:49:00 -0800
FYI,, according to my chart, RG174 has 19 db loss for every 100 feet,,, RG58 has 11 db
loss per 100 feet, at 400 MHz. If you try to splice without connectors, the loss
would be very great. We always assumed a loss of about 3 db even through a connector!
According to info that I found on the web you should be able to extent the cable of an
active antenna to approx. 30 meters, (that probably doesn't include connectors),, so 20
feet shouldn't be a problem. I couldn't see any loss of signal strength when I added,
(with miniature connectors, bought at a surplus store, HSC, they are on the web), 33
feet of RG174 to my GPS antenna. The sat. that were reading about 35 before, read about
35 after and the sat. that read about 55 before were reading about 55 after I extended the
cable!! I do drop to only 3 Sat on occasion, but then I am surrounded by hills and
large oaks. BTW, working with miniature connectors is a lesson in patience, steady
hands and delicate soldering!!
By doing it my way I only added one more connection rather than two if you cut the short
cable from the antenna. I did change the L shaped connector, on the antenna cable, to a
straight connector to make it easier to waterproof!
psn station #55
near Pilot Hill Ca
> Yesterday I got and SDR system up with one of the GPS systems we
> bought as a group. To lengthen the antenna I spliced in about 20 ft of RG174 into the
> little 5 foot cable of the antenna that came with the units. Hooked
> it all up and It worked well.
> Last night and today all got was and SDR error message stating "not
> enough GPS stat's being tracked".
> I replaced the antenna with one that I got from Synergy and had
> reserved for another installation and the problem disappeared.
> Any idea on how to test or trouble shoot this antenna???
> Best regards,
> angel mailto:angel@............
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