Seems like a resonance in the balun. I'd connect the two ends of the
balanced feed together, not using the balun, thus to form a 2 turn loop,
couple it to the 259 being used as a dip meter and see what gives.
73
Bob, K4TAX
----- Original Message -----
From: "Mike Bryce" <prosolar@sssnet.com>
To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
Sent: Saturday, October 12, 2013 10:59 AM
Subject: Re: [TenTec] Antenna is up, but the coupler doesn't like 160 meters
bob and the gang,
inserted the 259 and with the 1:1 balun.
resonate freq is 2.487 or there abouts
so the antenna as it sits is too short.
I'll re-check the length with my harbor freight made in china 300 foot
tape and see what each leg is (length wise)
Mike Bryce, WB8VGE
the heathkit shop
SunLight energy systems
J e e p
o|||||||o
On Oct 12, 2013, at 10:42 AM, Bob McGraw - K4TAX wrote:
The extra / external cap is used across the capacitor bank, starting at
position #4 and #5. Both on the Low and High Z sides. I find the text
is incorrect, the schematic is correct. Yes a .01 is way too much C by a
factor of 10x.
If you have a means to do so, what is the natural resonant frequency of
the antenna? I use my MFJ-259 as a grid dip meter effect to find the
resonant frequency. I'm not speaking of some frequency where the SWR is
1:1 or such.
I take a different approach to antennas. I first start with a resonant
antenna at the desired frequency, then adjust the height of the antenna
to attain the desired feed point impedance. I saw Jim Brown, K9YC
mentioned this in his earlier post as he used different coax impedance
lines dependant on the height of the antenna. I am not one to "prune"
the length of the antenna for some SWR value. Now in cases I know we
can't get the antenna at different heights specially as we get to 160M
and to some extent 80M. In these cases, the typical height above ground
does bring the center Z to 20 to 30 ohms. Nothing wrong with this. With
low loss coax or a balanced feed, just let the tuner deal with it.
That's what it is supposed to do. I find having a resonant wire is more
effective and easier to effect a good match.
73
Bob, K4TAX
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