Absolutely not true!!! If you take the aluminum required for
monobanders, 3 or 4 or 5 elements each, for three bands
10, 15, and 20M, and make one log out of it, you get the WARC
bands, all of every amateur band without regard to phone
or CW tuning, better F/B ratio across entire amateur bands,
Better SWR performance , with only a compromise in gain
of 1 to under 2 dB, depending upon the design.. Stack two
of them and you more than make up for that plus now
have a the flexibility of vertical angle control for 5 bands
with much less time spent on maintaining 10 yagis!
I know, having been there. I found this to be the best set
up for me, not being a contester and given my operating
requirements.
BTW, one can not make generalizations about LPDA performance
since, like yagis, it depends on what the design goal is. There are
significant design trades to be made for number of elements, boom
length, interconnecting transmission line impedance, freq range, ect.
73,
Chuck...K1KW
-----Original Message-----
From: Pete Smith [SMTP:n4zr@contesting.com]
Sent: Monday, March 18, 2002 9:38 AM
To: towertalk@contesting.com
Subject: RE: [Towertalk] M2 10-30LP8 log periodic Yagi
At 07:23 AM 3/18/02 -0700, Bill Eisinger wrote:
>I have the M2 7&10-30 "Skip Log" which is the same antenna with a 40m
>element added. I have it at 70' and been extremely pleased with its
>performance. As John says, it isn't the same as a large mono-bander but, it
>is a very competitive antenna. It is a big antenna and somewhat complicated
>to assemble however, the construction of the antenna is top notch. Also,
>M2's service is second to none.
If you don't need continuous frequency coverage I think log periodics are a
profligate waste of aluminum. As a working hypothesis, I've read that on
any given frequency a well-designed medium-boomlength LP has about the gain
and pattern of a typical 2-element yagi.
Weight and complexity are not trivial issues for installation and
maintenance, and when they are not accompanied by significant performance
improvements where we need them, then I think there are better choices.
Cost is also a consideration. I was not able to find any on the web in a
quick search -- Array Solutions just says "call us," which doesn't suggest
they're pushing the price as a selling point.
73, Pete N4ZR
Check out the World HF
Contest Station Database at
www.pvrc.org
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