This is quite curious.
Page 1 of the WA5VJB paper says, "Run the coax back down the antenna and along the boom keeping the radius small..." His hand-drawn illustration shows the feedline going down the boom then making a hard turn at the boom-to-cross arm plate.
The M2 instruction sheets for the 2MCP8A and 436CP16 antennas both state (in bold type), "Do not route feedline to boom to mast plate as exiting antenna here will adversely affect circular field."
Mr. Britain's paper is obviously focused on mounting the cross bar somewhere along the boom of a somewhat long antenna. The M2 instructions are for mounting short antennas from the back of the boom to the cross bar. Not the same situation. But, for a newbie like me, the definitive conclusion to this discussion is...I am still confused.
I was hoping to hang my M2 LEO antennas Monday morning but now not until after I call the M2 support line for their read on this.
73, Frank
FRANK W. KARNAUSKAS, N1UW ARRL MINNESOTA AFFILIATED CLUB COORDINATOR AMSAT NEWS SERVICE ROTATING EDITOR 1402 SUMMIT SHORES DR. BURNSVILLE, MN 55306 N1UW@GOKARNS.com 612-644-9174
-----Original Message----- From: AMSAT-BB [mailto:amsat-bb-bounces@amsat.org] On Behalf Of Gary Sent: Sunday, March 17, 2019 2:29 PM To: radiomb; amsat-bb@amsat.org Subject: Re: [amsat-bb] Attaching the coax to antenna boom
Yes, you can, just pay attention to how far your coax turn is from your driven element. There are a couple spots to avoid.
It is pretty well explained in Kent Britain's (wa5vjb) paper here: http://www.kk0sd.net/metalboom/metalboom.htm
73, Gary kk0sd
-----Original Message----- From: AMSAT-BB amsat-bb-bounces@amsat.org On Behalf Of radiomb Sent: Sunday, March 17, 2019 4:04 PM To: amsat-bb@amsat.org Subject: [amsat-bb] Attaching the coax to antenna boom
Building my new ground station and another question. I have always only elevated my antenna 90 degrees. I loose about 20 25 seconds while the azimuth rotator turns 180 degrees to track the rest of the pass. I have just let the coax hang off the back of the antennas in a big loop. I am afraid it will get hung up going 180 degrees. Question, Can I attach the coax to the antenna boom and run it back until it gets to the cross boom or will that throw off the radiation pattern? Thanks 73 Mike K4MIA
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