[Elecraft] Re: [Icom] Opinions re: HF Verticals?

Tue Oct 15 03:06:00 2002

sjolin said:
>> that they claim 2:1VSWR over an adjustable 320Khz segment of 20m.  Am
>> I just anal retentive of are there others out there that consider any
>> supposedly resonant antenna that presents a 2:1 VSWR as a NON-RESONANT
>> antenna?
>
> What they are saying is that at no point over the 320 khz range does the
> swr exceed 2:1. It maybe 1:1 at 14.160 and 2:1 at 14.000 and 14.320.
> Most commercial antennas for 20 meters will have similar ratings and
> they are resonant.

OK.  Wrong word.  Non-matched I suppose is what I should have used.

>
>> I consider an antenna that requires a tuner to operate at its design
>> frequnency with less than 1.5:1 to be a compromise at best.
>
> Most rigs will accept swr of 2:1 without reducing the power appreciably
> if at all. And even if you are using coax, you are probably not going to
> notice any loss in signal strength betwen 1:1 and 2:1. With this kind of
> swr you are not likely to need an antenna tuner unless you are a purist,
> fiddler, or have a very finicky rig.

My K2 gets a bit miffed if I present it with 2:1 and I can most definately
hear a difference between 1:1 and 2:2 when I'm tuning loop for use on
higher bands with the transmatch.  It's not as bad as being out to 4:1 or
so but, you can hear a difference.

> band will be at what you characterize as an acceptable swr. This
> obviously wont work if you also want to operate SSB on 14.313 (but why
> would anyone).

When I put up antennas, they're for QRO(and many more O's) operation.
While the amp will probably survive 2:1, I wouldn't personally operate it
that way unless it was under some sort of emergency and there was no other
choice.

I know - the answer is a transmatch.  I'm talking about the "oh crap"
situation here.  You have to communicate using HF, conditions are bad and
you have to run the AMP and your transmatch is DOA.

> BTW, an antenna can be resonant and have an swr of 1.5:1 or 2:1.  This
> has to do with impedance matching, not reasonant frequency. For example,

I follow.  I used the wrong term previously.  I have a transmatch but,
whenever possible, it's in bypass mode.  Most of my antennas are pretty
broadbanded at less than 1.5:1.

-- 
73 de John - KC4KGU
K2/100 #2490
http://www.kc4kgu.com