Hi everyone,
I would like to use a G-5500 rotor on top of a 20' telescopic mast with 2m and 70cm sat antennas. Assuming this isn't a bad idea to begin with, my next goal is to find RF cables that will work best with this type of tower given it will be raised and lowered frequently, thus causing a lot of extra cable flex. (I am not even sure of the best way to run cables up the to rotors when the mast is telescopic - ideas?)
I am looking at 20+' for the tower plus another 50' or so back to the shack. An suggestions?
Love those covenants... :)
73, Ollie, AJ1O
Use a cable with a stranded center conductor and braided shield for the section that will move. I used the flexible version of LMR400 at my previous QTH. These have higher loss than other types, but solid center conductors and foil shields will fail in a year or so when flexed repeatedly.
73,
John KD6OZH
----- Original Message ----- From: "Ollie Eisman" [email protected] To: "AMSAT BB" [email protected] Sent: Tuesday, January 08, 2008 17:31 UTC Subject: [amsat-bb] Cable question
Hi everyone,
I would like to use a G-5500 rotor on top of a 20' telescopic mast with 2m and 70cm sat antennas. Assuming this isn't a bad idea to begin with, my next goal is to find RF cables that will work best with this type of tower given it will be raised and lowered frequently, thus causing a lot of extra cable flex. (I am not even sure of the best way to run cables up the to rotors when the mast is telescopic - ideas?)
I am looking at 20+' for the tower plus another 50' or so back to the shack. An suggestions?
Love those covenants... :)
73, Ollie, AJ1O _______________________________________________ Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
Either run LMR-400 all the way (70-foot) or for lower loss run 50-foot 1/2-inch hardline (Andrew Heliax LDF4-50A) + 20-foot of LMR-400. Use N-female connectors on the hardline and N-male on the LMR-400.
The telescoping mast is not very rigid for a rotor and antennas so you need guy lines at 10 & 20 foot levels. Raising and lowering will be tricky so you should have 2-3 people to help you. Why not look for two sections of Rohn-25 tower (used can be had for $50/section)?
Ed - KL7UW
At 08:31 AM 1/8/2008, Ollie Eisman wrote:
Hi everyone,
I would like to use a G-5500 rotor on top of a 20' telescopic mast with 2m and 70cm sat antennas. Assuming this isn't a bad idea to begin with, my next goal is to find RF cables that will work best with this type of tower given it will be raised and lowered frequently, thus causing a lot of extra cable flex. (I am not even sure of the best way to run cables up the to rotors when the mast is telescopic - ideas?)
I am looking at 20+' for the tower plus another 50' or so back to the shack. An suggestions?
Love those covenants... :)
73, Ollie, AJ1O _______________________________________________ Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
73, Ed - KL7UW ====================================== BP40IQ 50-MHz - 10-GHz www.kl7uw.com 144-EME: FT-847, mgf-1801, 4x-xpol-20, 185w DUBUS Magazine USA Rep [email protected] ======================================
Either run LMR-400 all the way (70-foot) or for lower loss run 50-foot 1/2-inch hardline (Andrew Heliax LDF4-50A) + 20-foot of LMR-400. Use N-female connectors on the hardline and N-male on the LMR-400.
Speaking about coax lines i just get from an CATV installer who was working in my backyard replacing an old heliax line (That i was watching for over 2 weeks) about 4 run of 200 feets of old master line 75 ohm heliax the one who can be fitted nicely with a PL-259 connector.
The killing question!!! Did any one used this type of coax on a RX line with a mast head preamp on 432Mhz 1.2Ghz and 2.4Ghz? I know on a TX line the mismatch will give a SWR around 1.5 making the line probably too lossy on TX at microwaves frequencies even with both end adapted.
The installer was very happy to don't have to coiled about 800 feets of coax in about 4 feet of snow behind about 6 back yards full of winter stored items and sheds. The final destination of this coax line was the trash container...
My small ecological contribution!
Thank's for your input
Luc Leblanc VE2DWE Skype VE2DWE www.qsl.net/ve2dwe WAC BASIC CW PHONE SATELLITE
A 5500 rotor and two 18 foot antennas on a telescoping mast? Too much. Suggest Roln 25 or better. The mast will need a lot of Guys and the Top of the mast may be too small to fit inside the cost-extra mounting bracket for the rotor. As for Coax, I use LMR-600-UF. I had all cables custom cut and connectors pre installed. (davisrf.com) The lmr-600 will cost you about $3+ per foot, but.. for runs of less than 100 feet you can forget about coax loss on all freq below 1.2 ghz. This coax IS flexible enough to go around the rotor. If you are not using preamps, you can run 1 section from the Radio to the antenna and around the rotors. My 5500 and array M2, with lmr-600-uf has been in use for 4 years, no problems. Any satellite that I can hear, I can work.
Wf1f www.marexmg.org
--- Edward Cole [email protected] wrote:
Either run LMR-400 all the way (70-foot) or for lower loss run 50-foot 1/2-inch hardline (Andrew Heliax LDF4-50A) + 20-foot of LMR-400. Use N-female connectors on the hardline and N-male on the LMR-400.
The telescoping mast is not very rigid for a rotor and antennas so you need guy lines at 10 & 20 foot levels. Raising and lowering will be tricky so you should have 2-3 people to help you. Why not look for two sections of Rohn-25 tower (used can be had for $50/section)?
Ed - KL7UW
At 08:31 AM 1/8/2008, Ollie Eisman wrote:
Hi everyone,
I would like to use a G-5500 rotor on top of a 20'
telescopic mast with
2m and 70cm sat antennas. Assuming this isn't a
bad idea to begin with,
my next goal is to find RF cables that will work
best with this type of
tower given it will be raised and lowered
frequently, thus causing a lot
of extra cable flex. (I am not even sure of the
best way to run cables
up the to rotors when the mast is telescopic -
ideas?)
I am looking at 20+' for the tower plus another 50'
or so back to the
shack. An suggestions?
Love those covenants... :)
73, Ollie, AJ1O _______________________________________________ Sent via [email protected]. Opinions expressed are
those of the author.
Not an AMSAT-NA member? Join now to support the
amateur satellite program!
Subscription settings:
http://amsat.org/mailman/listinfo/amsat-bb
73, Ed - KL7UW ====================================== BP40IQ 50-MHz - 10-GHz www.kl7uw.com 144-EME: FT-847, mgf-1801, 4x-xpol-20, 185w DUBUS Magazine USA Rep [email protected] ======================================
Sent via [email protected]. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
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participants (5)
-
Edward Cole -
John B. Stephensen -
Luc Leblanc -
MM -
Ollie Eisman