Here's my perspective on "Gain and directivity aren't everything"...
During a 24-hour period the signal strength on any DX circuit may vary
by over 200 dB. Also, propagation is geographically "granular"...
meaning that when P5DX is 20/9 here, he may well be inaudible a few
hundred km away.
What that means is: If you're a DXer, being on the right band at the
right time is *much* more important than a few dB of antenna gain. How
do I know? Worked DXCC HR barefoot with low wire dipoles.
However, if you are an avid contester or hate spending more than 30
seconds in the P5DX pileup, then sure, a couple of dB may be worth it for you.
Ya makes your choice then pays your money.
73,
Rod Elliott VE3UW, VE3IRF ex- VE5RE, VE2BUW
DXCC HR
IOTA HR
5BDXCC
etc.
On 2010-01-22 16:21, Gene Fuller wrote:
It all boils down to the old adage "different stroke for different folks".
How many bands, zoning restrictions especially re height, dollars, wind and
ice conditions, reliability, avalability of local bargins, asthetics,
contests vs just x'ing, cost and reliability of cabling - RF, power and
control, and rotators, ability/willingness to climb, etc. But remember that
for the average location, you will most likely pick up more db's and new
"countries" by putting a fairly simple lower gain (4-6 db) antenna at 70
feet than going to a fancier higher gain (8-10 db) at 35 feet - if zoning
will allow it. There certainly are enough options available. And, as
someone, porbably wiser than most of us blogers once said, in effect, "It's
most important to just make a reasoned decision and get on with it. You'll
miss more dx with all of the interminal procrastination than you will by
lacking a few db's from your antenna.
----- Original Message -----
From: "jimlux" <jimlux@earthlink.net>
To: "Tower and HF antenna construction topics." <towertalk@contesting.com>
Sent: Friday, January 22, 2010 7:46 AM
Subject: Re: [TowerTalk] LP v SteppIR
Doug Turnbull wrote:
Gentlemen,
I wonder what the attraction of the LP is when one can use a
SteppIR.
Am I wrong to believe that the Fwd gain and FB are better for a Yagi of
the
same number of elements tuned to the frequency of interest than an LP?
Is
it not the case that LP antennas have a lot of metal and hence wind
loading
for what they achieve? Wind loading is as important to me as gain and
directivity. It is a big balancing act. Granted the SteppIR has a
good
bit of electronics but in my experience they seem to be reliable.
Perhaps
the SteppIR is more expensive for the same performance but Aluminum is
pretty dear.
You've pretty much summarized the differences..It's a systems
engineering question and depends on your ultimate desires.
The SteppIR is more complex, but has less wind resistance, and
potentially better gain and F/B, and can switch 180 degrees very
quickly, but takes some short time to change frequency.
The LPDA is simpler (no moving parts), lower gain and f/b,
instantaneously changes frequency, has more wind drag area and is
heavier (I'm not sure about the latter).
If you're running comms for an embassy, running kilowatts on RTTY, the
dual LPDA is the ticket, especially if you're running an HF hopper or ALE.
If you're a ham, wanting to eke out the last tenth of a dB, the SteppIR
might be a better fit.
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