Bill:
You are correct as to the antenna performance. Relationship to nearby
objects, trees, bushes, houses, and etc will have a marked effect in antenna
performance, especially with verticals. As to radials, they ideally should
be spaced equally and "radiate" in all and equal directions from the base of
the antennas. However, any number of radials in the ground, wandering
around any place, around the house, around the flower beds and etc will be
much better than no radials at all. Verticals which are reduced electrical
length don't perform as well as full size verticals. It's easy to get a 10M
to 20M vertical to work quite well. After all a 20M 1/4 wave is 16 or so
feet. A 75M 1/4 wave is 66 ft or so. Therefore, the physical size of the
20 - 10 M vertical is closer to the electrical wavelength. Thus it is
nearly a "full size" antenna.
When I lived in FL I had 2 antennas, one a Butternut HF6V with WARC bands
and a center fed 125 ft wire. I had the Butternut set up for the digital
portion of each of the bands. The wire antenna used a balanced feed and a
tuner. I tuned it to the frequency I wanted to operate. I noticed when
working digital modes that as a signal went into a fade on one antenna it
was most often up in strength on the other one. From that, I made a timed
and sequenced switcher. When I noticed a signal beginning to fade, I
manually flipped a switch and during the next non-transmit interval the
system swapped antennas. I made many QSOs that way and rarely lost a
contact.
>From a Tentec point of view, I also had a sampler and counter attached to
the error control indicator on the PK 232MBX. If no error requests were
detected on 3 consecutive Packet or AMTOR transmissions then the system
reduced power, by one step of 10, of my transmitter by feeding a DC voltage
to the ALC jack on the Paragon. If the error rate went up by the receiving
station the system increased transmitter power by reducing the ALC control
voltage. Most of the time I would see power output in the 2 to 5 watt
range. It's amazing what good antennas and a bit of technology can do.
73
Bob K4TAX
----- Original Message -----
From: "William Mansey WA2PVK" <res0wsci@verizon.net>
To: <TenTec@contesting.com>
Sent: Monday, September 02, 2002 3:51 PM
Subject: [TenTec] Even MORE on vertical antennas!
Hello,
I had a Hustler 6BTV antenna mounted in the side yard and was not
satisfied with the performance. I do NOT blame the antenna as it was not
the problem. The problem is that I do not have enough room to mount the
antenna clear of nearby objects nor was there sufficient room for proper
radials. This antenna is well made and probably would work well if properly
positioned.
My solution, to my limited space, was to try a Cushcraft MA5V, I put
this on the roof with a short (5') mast and a vent pipe mount. I set the
element lengths according to the instructions and only had to make two
adjustments later.
This antenna is only about half the length of the 6BTV because it is
made for 20, 17,15,12, and 10 meters. It has four 48" radials. I was
pleasantly surprised at the performance. I have two wire antennas. These
are an multi-band inverted V and a sloper. The received signal strengths
when using the MA5V are comparable to when I switch to either wire antenna.
In some cases the signals are actually stronger with the MA5V - probably due
to polarization. I would recommend this antenna for anyone who, like me,
has space limitations. I was skeptical of the antenna's performance and
actually expected mediocre performance due primarily to the small size of
the antenna. I am most pleasantly surprised with how this thing works! It
is quite good indeed. It has far exceeded my expectations.
See the reviews on Eham for more. I had none of the problems mentioned.
(metal burrs and other issues. These problems have obviously been
corrected)
I hope my comments do NOT cross the line that separates opinion from
advertising! I have nothing to gain from my testimonial.
To take care of the Ten-Tec connection to this post - - - I am using
this antenna with my Jupiter and will also be using it with my Orion.
73; Bill
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