Dear Art: Indeed, fishing poles are a main stay of amateur radio - and
very good value.
As you have pointed out, I am a patent attorney (who is not looking
for additional work). I am also a licensed professional engineer in
Michigan. These two professions facilitate my "day job."

As a follow on to your note about a certain Rohn tower (with an
aside that their commercial products always conformed to standards - I
have checked some of their calculations) I note that Heights Tower once
included in their literature an accurate account of how to calculate
"strength" and wind effects on their line of welded aluminum towers. It
was clear from what they presented just what assumptions were being
made. Such a full disclosure is commendable.
73 Mac N8TT

--
J. Mc Laughlin - Michigan USA
Home:

"Art Unwin KB9MZ" wrote in message
. ..
Mac,
I understand your line of work is a patent attorney
but it easily could have been one as a mechanical engineer.
Your description of antenna mechanical design is outstanding.
snip

The Tennadyne antennas are well built, perform quite nicely and are ruggedly
built. My T-10 withstood 5 major ice storms in central Iowa before I moved.
I replaced it with a smaller T-6 at the new I moved. I am VERY pleased with
its performance and the customer service at Tennadyne has been superb. Two
additional positive factors:

The Tennadynes are light weight and low wind-load, and at the same time
rugged.

The price is exceptional.

I made some relatively careful meaurements of F/B on the T-10 with a step
attenuator, and found the Front to Back ratio was never less than 17 dB from
13 through 30 Mhz, and I had no trouble working anyone in any pileup that I
entered.

I have not made similar measurements on the T-6, which is lower (50 ft
instead of 70 ft), but I have yet to not be able to work someone in a pileup
that I wanted.

Obviously the forward gain of a yagi is going to be better than a comparbly
sized LP. The frequency agility and price performance however, are
unmatched, except for the most die hard contester. I like what the SteppIR
continuously tuned yagis offer, but I don't like their unproven (over
decades) mechanical reliability nor their high price.

If I was starting over, and could afford triple the price of the LP, AND
felt certain that the SteppIR would work reliably in all sorts of weather
conditions for at least 10 years, I would be sorely tempted. This is not to
dump on the reliability of the SteppIR...they just haven't been up long
enough, much less long enough in difficult environments. It sure looks like
a wonderful concept.

....hasan, N0AN


"Lee." wrote in message
...
Hello Folks
I would like to get a HF log periodic antenna 13 - 30 mcs can anyone
recommend one? opinions please???

Lee.

Well Mac the fold over was simple to check, they had just one tube in
tension when using the fold over. I kept that piece of tubing for ages
since the necking shape was so well defined. And why I mentioned it
was that I believe
stress aplied was in the region just below and in the plastisation
area below the Y.P. Either way they quickly beefed up that area with
welded plates.
On the patent area I can really understand your reluctance to seak new
work.
I had a couple of forays into that area and found it most fraustrating
since it now seems to come down to a battle of words and in one case a
throw out because I had used a continental 7 which had a cross on it !
I have one more to write , for my own satisfaction, where even if the
claims are not protectable the completion of the subject will give me
closure plus another area for antenna experts to be derisive of.
I once spoke to a miltary patent attorney from Washington regarding
the direction the patent office was going and he told me that most of
their
patents were hnow being rejected however the 15 minuite appeal
was being used with great success.
So cost cutting aproaches appears to be financially successful in
one section by overloading another section !

Cheers
Art







"J. McLaughlin" wrote in message ...
Dear Art: Indeed, fishing poles are a main stay of amateur radio - and
very good value.
As you have pointed out, I am a patent attorney (who is not looking
for additional work). I am also a licensed professional engineer in
Michigan. These two professions facilitate my "day job."

As a follow on to your note about a certain Rohn tower (with an
aside that their commercial products always conformed to standards - I
have checked some of their calculations) I note that Heights Tower once
included in their literature an accurate account of how to calculate
"strength" and wind effects on their line of welded aluminum towers. It
was clear from what they presented just what assumptions were being
made. Such a full disclosure is commendable.
73 Mac N8TT

--
J. Mc Laughlin - Michigan USA
Home:

"Art Unwin KB9MZ" wrote in message
. ..
Mac,
I understand your line of work is a patent attorney
but it easily could have been one as a mechanical engineer.
Your description of antenna mechanical design is outstanding.
snip