Hello: New to satellite communication I plan to construct a fixed station to work satellites.
I am looking to identify best type of coaxial cable to run from my VHF/UHF antennas around az/el rotors to the preamplifier (located on the fixed mast/support).
Most important coaxial cable requirements include:
Highly Flexible (in upper midwest climate: temperatures range from 15 deg to +100 degrees F) in Repeated (continuous) flexing Low Loss (while super flex Heliax would be my preference, it¹s not designed for repeated flexing this application sees Full shielding (preserve S/N and overall system noise figure).
I can compare the loss values from manufacturer data sheets; my main interest here is to learn what type of cable has withstood the repeated (continuous) flexing required to work satellites?
What cable type do you recommend based on your experience? Thank you 73,
Heliax Superflex? Times Microwave LMR-600UF? EcoFlex 15 Plus? Belden 9913Flex? Something else?
David J. Schmocker, KJ9I
I have been using LMR-600 UF for 15+ years. Its great. I no longer worry about coax loss for 2m and 440. My runs are 100 feet. I work EME with a Single yagis.
Single 2meter M2, 20 element CP Single 440 M2 44 element cp.
Miles, WF1F
On 8/26/2018 8:24 PM, David J. Schmocker wrote:
Hello: New to satellite communication I plan to construct a fixed station to work satellites.
I am looking to identify best type of coaxial cable to run from my VHF/UHF antennas around az/el rotors to the preamplifier (located on the fixed mast/support).
Most important coaxial cable requirements include:
Highly Flexible (in upper midwest climate: temperatures range from �15 deg to +100 degrees F) in Repeated (continuous) flexing Low Loss (while super flex Heliax would be my preference, it�s not designed for repeated flexing this application sees Full shielding (preserve S/N and overall system noise figure).
I can compare the loss values from manufacturer data sheets; my main interest here is to learn what type of cable has withstood the repeated (continuous) flexing required to work satellites?
What cable type do you recommend based on your experience? Thank you 73,
Heliax Superflex? Times Microwave LMR-600UF? EcoFlex 15 Plus? Belden 9913Flex? Something else?
David J. Schmocker, KJ9I
Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
I use 9913F7. Works great.
There are a number of alternatives. Some of the stuff is great for a year or two, then the jacket degrades. Brand names USUALLY get a reliable product.
Hope to hear you on the air.
Norm n3ykf On Mon, Aug 27, 2018 at 2:26 AM David J. Schmocker kj9idave@charter.net wrote:
Hello: New to satellite communication I plan to construct a fixed station to work satellites.
I am looking to identify best type of coaxial cable to run from my VHF/UHF antennas around az/el rotors to the preamplifier (located on the fixed mast/support).
Most important coaxial cable requirements include:
Highly Flexible (in upper midwest climate: temperatures range from 15 deg to +100 degrees F) in Repeated (continuous) flexing Low Loss (while super flex Heliax would be my preference, it¹s not designed for repeated flexing this application sees Full shielding (preserve S/N and overall system noise figure).
I can compare the loss values from manufacturer data sheets; my main interest here is to learn what type of cable has withstood the repeated (continuous) flexing required to work satellites?
What cable type do you recommend based on your experience? Thank you 73,
Heliax Superflex? Times Microwave LMR-600UF? EcoFlex 15 Plus? Belden 9913Flex? Something else?
David J. Schmocker, KJ9I
Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Antenna configuration:
Yeasu Azimuth and elevation rotor.
Solid fiberglass horizontal mast, 2.00 diameter, 14 feet long.
M2 2-meter (20 element) on one end, M2 440 (44 element) on the other end.
I installed two 80 foot sections of LMR 600-UF from the shack to top of the tower.
I have the option of installing a tower mounted preamp, but just added a Female to female N-Connector at this spot. Preamp are in the Shack.Higher loss, but I have not Fried a Preamp in 15 years.
I installed 2, 20 foot sections of LMR-600-UF is used to go around the AZ/EL Rotor to the antennas (one for each ).
LMR-600-UF is flexible enough to be used around rotors.Just following the bend radius rules for this cable.
Issues:
I used high quality UV-stabilized tie wraps to attached coax to Masts and antenna booms. After 10 years of usage, my SWR went bad on the 2-meter beam.
The vibration and flexing of the antenna boom and rotor masts caused the tie wraps to "SAW" through the outer layers of insulation on the LMR-600-UF.
I had to replace the two 20 foot sections of LMR-600-UF.They were full of water.
Also the 2-meter tuning stubs were also Sawed through by the tie wraps.
I replaced all of the 10 year old damaged cables.
I reinstalled by using Spiral-Wrap over the sections of coax that were going to come in contact with tie wraps. I would add about 4 inches of Spiral-Wrap and then UV black tape to hold the Spiral-Wrap in place.Then I installed 2 tie wraps over Spiral-Wrap.
New Rules.
Never use a Tie-wrap on a bare section of coax insulation (if there is any chance of vibration or flexing). Always cover the coax insulation with Spiral-Wrap to prevent the tie-wrap from sawing through your coax.
On 8/26/2018 8:24 PM, David J. Schmocker wrote:
Hello: New to satellite communication I plan to construct a fixed station to work satellites.
I am looking to identify best type of coaxial cable to run from my VHF/UHF antennas around az/el rotors to the preamplifier (located on the fixed mast/support).
Most important coaxial cable requirements include:
Highly Flexible (in upper midwest climate: temperatures range from �15 deg to +100 degrees F) in Repeated (continuous) flexing Low Loss (while super flex Heliax would be my preference, it�s not designed for repeated flexing this application sees Full shielding (preserve S/N and overall system noise figure).
I can compare the loss values from manufacturer data sheets; my main interest here is to learn what type of cable has withstood the repeated (continuous) flexing required to work satellites?
What cable type do you recommend based on your experience? Thank you 73,
Heliax Superflex? Times Microwave LMR-600UF? EcoFlex 15 Plus? Belden 9913Flex? Something else?
David J. Schmocker, KJ9I
Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
On 8/27/18 4:45 PM, Miles via AMSAT-BB wrote:
I installed two 80 foot sections of LMR 600-UF from the shack to top of the tower.
I have the option of installing a tower mounted preamp, but just added a Female to female N-Connector at this spot. Preamp are in the Shack.Higher loss, but I have not Fried a Preamp in 15 years.
I had to replace the two 20 foot sections of LMR-600-UF.They were full of water.
I'm going to take the contrarian viewpoint (again). A LNA in your shack is not going to do you justice if you've already set the noise figure with a long, expensive, attenuator.
160' of LMR600UF = ~$320
80' loss @ 150 = 0.8dB 80' loss @ 450 = 1.3dB
Let's add in 0.5dB of loss for various connectors, and the best you can do is something like a NF of 1.8dB at 2m, and about 2dB up at 70cm. So much for that fancy 0.5dB NF preamp, right?
Why not spend that money on a _good_ or _cheap_ (pick one) LNA, RG-8X/RG-213 at half the price, and add some power to overcome cable loss in the shack? Good grounding goes a long way to protecting your LNA, which should be off during storms.
A preamp (LNA) belongs at the antenna, not in your rig. That is, unless you've attached the rig directly to your antenna. :-)
--- Zach N0ZGO
Hi David,
I have been using LMR-240-UF for that application with great success. A 10' piece is only .6 dB loss at UHF. For all the current LEO satellites that should not degrade performance enough to make a huge difference.
Howie AB2S ________________________________ From: AMSAT-BB amsat-bb-bounces@amsat.org on behalf of David J. Schmocker kj9idave@charter.net Sent: Sunday, August 26, 2018 8:24 PM To: Gary Lockhart via AMSAT-BB Subject: [amsat-bb] satellite flexible rotor-section coax question
Hello: New to satellite communication I plan to construct a fixed station to work satellites.
I am looking to identify best type of coaxial cable to run from my VHF/UHF antennas around az/el rotors to the preamplifier (located on the fixed mast/support).
Most important coaxial cable requirements include:
Highly Flexible (in upper midwest climate: temperatures range from 15 deg to +100 degrees F) in Repeated (continuous) flexing Low Loss (while super flex Heliax would be my preference, it¹s not designed for repeated flexing this application sees Full shielding (preserve S/N and overall system noise figure).
I can compare the loss values from manufacturer data sheets; my main interest here is to learn what type of cable has withstood the repeated (continuous) flexing required to work satellites?
What cable type do you recommend based on your experience? Thank you 73,
Heliax Superflex? Times Microwave LMR-600UF? EcoFlex 15 Plus? Belden 9913Flex? Something else?
David J. Schmocker, KJ9I
_______________________________________________ Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: https://nam01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.amsat.o...
participants (6)
-
David J. Schmocker -
Howie DeFelice -
Miles -
Miles (WF1F)
-
Norm n3ykf -
Zach Metzinger