If it is 300 feet total horizontal with vertical part at midpoint, I think
it is resonant about 3.55 and 350 total horizontal about 3.12 Mhz.
If you match it wherever it is resonant it looks like the bandwidth is not
much - like 75 Khz. between 2-1 SWR points and if the antenna had like
7-1/2 feet either side of center it would be resonant at 3.8 and have about
200 khz. between 2-1 SWR points.
I misunderstood and thought it was an L instead of a T.
Stan, K5GO
On Mon, Dec 19, 2022 at 10:33 AM Lux, Jim <jim@luxfamily.com> wrote:
> On 12/19/22 8:28 AM, Stan Stockton wrote:
> > 350 feet is about 5 quarter wavelengths at 3.8 MHz. Quarter wavelength
> is about 65 feet or so. If that thing is really 350 feet long you should
> see resonance at about 700 kHz, in addition to every odd multiple of a
> quarter wavelength. Was there a typo or is this really an inverted L that
> is 350 feet long?
> >
> > Stan, K5GO
>
> It is, I think, about 175 feet either side of the vertical part. So,
> electrically, it might be more like a 50+175 foot wire, roughly 70
> meters. But it's really more of a capacitive top hat on a 50 foot
> vertical.
>
>
>
> > Sent from my iPhone
> >
> >> On Dec 19, 2022, at 2:57 AM, w5jmw@towerfarm.net wrote:
> >>
> >> Hello all.I have a t antenna.50ft vertical and roughly 300 ft ntip to
> tip horizontal.I get a nice drop and resonance at abt 3.8 mhz.Is this weird
> resonant point normal??I would think it would be lower.I have another at
> abt 2.2 but almost a 3-1 swr..Normal ? I have used an inverted l before and
> resonant was abt right with a 1/4 wave length..thanks..john
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