I know when one looks at the dB loss charts, the math might suggest it shouldn't matter... but in practice, even a couple feet have been known to make a significant difference with some weak signal UHF downlinks, most notably SO-50. *insert anecdotal stories here*
Anecdotal stories...
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http://www.jerryclement.ca/HamRadio/VE6AB-Portable-OPS/i-nwqF8wQ/http://www.jerryclement.ca/MachineShop/Antenna-Werks/i-sNNxBCLhttp://www.jerryclement.ca/MachineShop/Antenna-Werks/i-7qxcsD6looks like about 4-5 feet of cable, if that...
Observation: "I noticed some loss in the signal"... enough that he felt the need to add a preamp.
Math: RG-58 loss @ 440 Mhz 10.4 dB/100' -- we're talking half a dB maybe? That's assuming 5 feet, so it may be even less.
And this from a guy with an awesome machine shop who builds antennas of all types on a regular basis, who's been all over Canada operating satellites and was even featured on the cover of an ARRL publication. He's not new to any of this...
http://www.jerryclement.ca/HamRadio/VE6AB-Portable-OPS/i-qgJp2Bw===
I built one of those CJU antennas myself... just 3.5 inches of coax and mounted on top of my HT, it hears fine. But 2-3 feet of coax, not so much. These different feedlines were two ends of the SAME professionally manufactured jumper cut into two pieces. It was RG-174, math works out to less than a dB difference in the loss. I have been told repeatedly that less than a dB should not be noticeable in received signal strength... yet it was. I've been a ham for over 40 years... GROL, had 3-4 repeaters, maintained a network of packet sites; this is my second go on satellites.
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A good number of experienced ops have been giving out this advice for YEARS to new sat ops making homebrew antennas... goes like this:
'Can't hear SO-50 with my new homebrew antenna.'
How much coax you have between it and radio?'About 5-6 feet.'
Cut 2-3 feet off and try it again.'I can HEAR it now!!!'
What kind of coax was it anyway?'Some cheap crap I had laying around.'
Throw that out and get some better stuff.'Absolutely!' <few days later> 'Hey you were right!'
These were most often new hams who were not biased by something they had read and listened to the hams with years of actual 'in the field' experience.
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I still refuse to debate the topic, but I offer these anecdotal stories for whatever they may be worth to the OP and other readers. A person can believe them or not, makes no difference to me. One can also go try
5' of crap coax in the field and see if it makes an actual difference or not. But when 'I' spend my time and hard earned money to travel to a remote location to do expedition style sat ops, guess what... I'm taking
only good quality coax. Even if I am deluded and wrong, I will feel better... BUT if I am right, the cost was relatively insignificant compared to what I spent on all other things (gas, meals, motels, etc). I would say the majority of experienced sat ops have learned this lesson already.
Which is my point to the OP, same point as N8HM and W5PFG I would assume... don't learn this lesson the hard way, go ahead and get the good stuff in the first place.
73, Kevin N4UFO