Has anybody actually measured the loss on their coax from back of amp to top of tower, for various freqs if a multiband yagi used..... or what ever band your monobander is? I mean using accurate watt
I've measured loss in various lengths of various coax types on the ground by several methods. The first time around, I used an HP generator as a source and an HP Spectrum Analyzer as a load and voltm
Amen Jim, Amen! Measuring the RF power at the antenna feedpoint can INDEED be a rude and abrupt bubble buster! What matters then is what if anything is done about it and aye, there's the rub. Patrick
I've done it several times but many years ago at a previous QTH. IIRC, I loaded my amp to a KW out into a dummy load in the shack through an RF ammeter and measured the current. Since I had a crankup
Yes, I've measured my feedline loss using the Open and Short circuit method; results were in line with calculated values. I wonder if the UK is unique in specifying power limits _at the antenna_? In
When I first put up my 160m vertical, I used a 140' run of RG-214, mil-spec silver plated doubly shielded. Terminating the far end with a 50-ohm dummy load, I used my so-called RF watt-meter and th
-- ORIGINAL MESSAGE --(may be snipped) REPLY: "Top of the tower" got me to thinking. One way to solve this problem would be a tower-mounted amplifier. It should be broadband, i.e. no tune except for
I routinely measure at the back of the amp and as close to the antenna as is easily possible. I don't usually climb the towers but measure at the base of the tower knowing that there is additional lo
Go for a "tower-mounted shack" and you will even solve the feed lines losses we're talking about in another thread. By the way. That's what we do for medium-power microwave telecommunication equipmen
antenna_? In other words, you can run whatever power you need in order to overcome feedline loss. I don't>believe it's a healthy regulation - it hardly encourages good engineering of the station! Is
antenna_? In other words, you can run whatever power you need in order to overcome feedline loss. I don't>believe it's a healthy regulation - it hardly encourages good engineering of the station! IE:
VF of RG-393 is .70 as with other PTFE coax. The highest coax loss of my station is on 2m with .7db through LCF 158-50 with UCF78-50 pigtails, total length is 75m from antenna relay to antennas. On a
You want some lossy coax? I have a couple old rolls where both the center conductor and shield are nichrome. VERY lossy stuff! David Robbins K1TTT e-mail: mailto:k1ttt@arrl.net web: http://wiki.k1ttt
What would they use nichrome coax for? Some sort of test jig for heating? For use in a refractory or corrosive environment? I think I've seen hastelloy or something other superalloy. I've seen stain
Author: Mike Fahmie via TowerTalk <towertalk@contesting.com>
Date: Sun, 30 Nov 2014 01:07:51 +0000 (UTC)
How about maybe in a underground nuclear test bore hole, it would deliver the signal before the coax melted entirely (?).-Mike What would they use nichrome coax for? Some sort of test jig for heating
Tektronix used nichrome coax for many of its passive probes, the almost perfect lossy cable! Pretty small coax though!! I would believe other probe mfrs used it too. Don W7WLL How about maybe in a un
This was used in a high voltage test lab where they were trying to measure voltages from lightning and switching surges on 345kv or higher voltage power lines. I never saw that setup myself but the s