All these "modern", solid state, PA have the same problem, they are "protected"
and the "protection" rolls back the power as soon as they detect reflected
power. Little depending on make and design they roll back more or less. That's
why the manufacturer offer built in tuners. The "old days" with a pi-filter on
the output could be tuned to most anything below SWR of 1:3 or even more, and
they didn't have (needed maybe) the "protection". As long as you didn't kill
the final tubes by overheating them, you were OK. Do we like to have the "old"
tube final back? Maybe.
73 de,
Hans - N2JFS
-----Original Message-----
From: Roger (K8RI) on TT <K8RI-on-TowerTalk@tm.net>
To: towertalk <towertalk@contesting.com>
Sent: Sat, Oct 26, 2013 2:47 pm
Subject: Re: [TowerTalk] Tower and antenna decisions
On 10/26/2013 1:56 PM, steve jobes wrote:
> Rick I disagree with your statement. As a owner of a Tennadyne T-10 and
currently a T-12 your statement is flat out wrong. I swept my T-12 with my rig
expert AA-230 analyzer and it was below 2-1 across the 13-30 mhz. range. Not
sure what you are talking about, OR WHAT BRAND. But to say mediocre SWR is a
false statement.
When I had a Tokyo Hy power 1.5 Kfx, the power was rolling back by as
soon as the SWR started to climb above 1:1. by 1.3:1 it was down over a
100 watts. At 2:1 it would have been down by 300 or more IIRC. I would
run a tuner on anything over 1.3:1.
My Quadra doesn't appear to be any more tolerant. Unfortunately the
Quadra is now ailing.
When I used tube gear, 3:1 was tollerable
73
Roger
> 73,
> Steve W1DXH
>
>
> -----Original Message-----
> From: Richard (Rick) Karlquist <richard@karlquist.com>
> To: towertalk <towertalk@contesting.com>
> Sent: Fri, Oct 25, 2013 7:25 pm
> Subject: Re: [TowerTalk] Tower and antenna decisions
>
>
>
> I briefly looked at log periodics and one thing
> that hasn't been discussed here is the mediocre
> SWR of LPDA's. You're pretty much going to have
> to use a tuner, and you also have increased feedline
> loss. Might work for some users, but I'm sticking
> with my SteppIR antennas (3 of them so far).
>
> An LPDA would however, make a good broadband receive
> antenna for a skimmer, if you want to optimize
> one direction.
>
> Rick N6RK
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