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Par 6m Stressed Moxon

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I received my Par 6m Stressed Moxon today. Had it together in 10 minutes and up on the mast at about 25′ another 10 minutes later. Now all that is left is to actually hear some activity.

Using the WA3TTS for comparison, with the Moxon pointed towards PGH I was getting an S9 sig on WA3TTS. With my HF wires I would get S2 or less.

I heard K8LEE and another station on tropo today as well as WA4VUT, W2TG and a few others via Es. C6ANP/B was about S9+10 a little earlier. Heard W9DR/B and some other beacons as well.

I only have an armstrong rotor, and it’s a real pain in the neck to find an opening if you don’t have the luxury of easily turning your antenna. The F/B ratio on this Moxon is quite impressive. I might want to make something equivalent to the Par Omniangle for the sake of hearing omnidirectionally.

Hopefully we’ll start seeing some good E-skip pretty soon on 6m and I can try out the Moxon some more

Written by Mike

May 3rd, 2011 at 2:46 pm

Posted in Antennas,VHF_UHF

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HF Vertical Antenna Considerations

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I’ve been looking into various options for multiband HF operation.   The cheapest and easiest [typically] would be a variety of dipole fed with ladderline.   The problem is my lot size.    The whole lot is 100×150, but the house, side yards and front yard occupy 75×150 and the remaining 75×150 is occupied by a back deck, underground utilities, a fenced in area for the dogs, and a small portion of wooded area — no trees at all on this part of the property.

Over the years I’ve used various wires, and they always performed better than nothing but they never performed, mostly due to me never having an option to put them up at a proper height or with a proper length to work all the way down to 80m.   Forget about 160.

So I’ve been looking at various verticals.   Some pros to a vertical is that you often can fit them into a space that a wire cannot fit, and they have a low takeoff angle so they are fairly decent DX antennas.   Some cons are the fact multiband verticals tend to be long and sometimes cannot handle the abuse that a high wind area poses; also many require a radial system, and constructing a proper radial system [especially if you are ground mounting a vertical] is not for the faint of heart.

Option #1:  Ground-Mounted Vertical

A Hustler 6BTV falls into this category and would be my vertical of choice if I was able to ground mount it.   I typically would not have had an objection to a ground-mounted vertical.  However, GMVs require a proper ground system to work as advertised.    Just because a vertical may tune up with or without a tuner without the use of radials doesn’t mean it’s radiating the signal where it is most useful.   I’ve been doing a lot of reading about radial systems, and although I would not object to going through the trouble to install a proper radial system, it’s just not in the cards.      It is recommended that a GMV be located at least 20 feet away from tall frees, houses, metal structures [including fences].   It is also recommended that the ground system consist of at least 20 radials cut to at least 1/8 wavelength on the lowest band that you wish to operate (33 feet for 80m and 16 feet for 40m).

In the area where I could possibly install a GMV there is a fence surrounding it within 15 feet of the location and a septic system and underground electric beneath it.   I could never lay out a proper ground system with the fence in place, may have trouble with interference from the underground electric, and would certainly have a problem with the chain link fence being in close proximity to theantenna as well as the house and tall trees just beyond the property line.

Option #2:  Elevated Vertical without Radials

I’m not sure how well this category of verticals works, but one antenna in this category is the Hy-Gain AV-640.    This antenna is an 8-band vertical (80/40/30/20/17/15/10/6) that does not require a radial system.   It is 25-1/2 feet tall and weighs 10 lb.   I’ve read good reviews and bad reviews.   The bad reviews included reports of missing parts upon shipment, sometimes shoddy craftsmanship (holes not lining up, burs around machined edges), water intrusion into various parts of the antenna system where it does not belong, etc.   Good reviews include the fact that it is easy to put together, easy to work on, works very well on 10m-30m whilst being somewhat of a compromise on 40m, is easy to tune, and that is pretty good at withstanding the wind.

An Antenna like the AV-640 is more of an option for me.   However, I’d still like to get it up in the air.   I don’t have a tower, but i believe I have the needed real estate to erect something and will likely pursue that.   I’d mount an AV-640 elevated, but not with a height clear over the top of the house at this point.

Summary:

Obviously the low takeoff angle bothers me for working local, but unless you have money and available real estate you can’t always have your cake and eat it too.   I like working predominantly the state QSO parties / contests and Field Day.    I do occasionally participate in other contests that are worldwide.

I do like the vertical because it takes up minimal horizontal space, doesn’t require wires strung all over the place, is easy enough to construct and put up, and is easy to maintain.

I’m likely going to go with a vertical that does not require a separate radial system such as the AV-640 (but perhaps not the AV-640 when all is said and done).   When this will happen, I am not sure.

Written by Mike

April 6th, 2010 at 8:52 pm