[Boatanchors] Beam antenna question
rayfrijr at msn.com
Sat Feb 18 20:51:44 EST 2012
The beam is the Model EX-14 or "Explorer 14" by Telex/Hy-gain. Manufactured back in the 80s.
Beam is a four element one. The driven element design has center driven element with a rear sleeve and a front sleeve. HyGain calls it a Parasleeve system.
Kind of like two short parasitic elements, one in front of and one in back of the driven element, spaced about three or four inches from the driven element.
Anyhow, the 15-20 meter reflector has 15 meter traps in it. Then in front of that is the 10 meter reflector with no traps. Then we have the driven element which has
only 15 meter traps in it . Then the 10-15-20 meter director has 15 and 10 meter traps in it.
So in the end we have three elements for each band and four elements total. The matching system is best thought of as an overgrown hairpin loop matching system.
Basically two parallel pieces of tubing, shorted at the very end. The open end connects one side to each side of the driven element, and the coax is also connected to the
> Date: Sat, 18 Feb 2012 20:24:03 -0500
> From: anchor at ec.rr.com
> To: rayfrijr at msn.com
> CC: boatanchors at puck.nether.net
> Subject: Re: [Boatanchors] Beam antenna question
> Hi Ray,
> Does this beam have separate traps for each band, or "one does all"
> like Mosely? Anyhow, maybe spiders in a 15m trap if they're separate.
> I've had that problem. Probably not corrosion at the traps-element
> connx, haven't heard of that much, if at all.
> Al, W8UT
> "There is nothing -- absolutely nothing -- half so much
> worth doing as simply messing about in boats"
> Ratty, to Mole
> On 2/18/2012 5:11 PM, RAY FRIESS wrote:
> > Need some advice from the fellow old timers here ... or even the wise newcomers...
> > I have a HyGain beam antenna, the Explorer 14. Fairly old, but has been a great performer with nearly unity SWR from one end of the band the other on 10, 15 and 20 ..
> > until recently.
> > Now, a few weeks ago the SWR on 15 shot up so high that it nearly pins the SWR meter. However, the SWR on 20 and 10 are still less than
> > 1 to 1 and it continues to load fine. Barely moves the needle on the SWR meter.
> > My question is, what should I suspect? A 15 meter trap gone bad, or maybe corrosion in the area where the traps and elements are clamped together?
> > The antenna has been up for about five or six years now, without any trouble prior to now. Sometimes there would be brief periods of a few hours with a
> > high SWR such as when we had snow accumulate on it, but when it dried up, the SWR came back down to normal.
> > I thought if it was either a bad trap or a corroded element to trap joint that the SWR would be all out of kilter on all three bands, not just 15 meters.
> > I'm sure it's something with the antenna. I use a TS-50 solid state rig with the automatic antenna tuner. It still loads and puts out full power on 20 and 10,
> > but on 15 because the SWR is so high, the power dips down to about 5 watts output on the beam. I can load a regular dipole without problems.
> > I tried taking the auto tuner out of line to see if it was having a problem on 15, but I still get the same high SWR without it in line.
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