[AMRadio] new antenna and matchbox a bust.


Craig C. Heaton wd8kdg at worldnet.att.net
Mon Jan 29 12:37:18 EST 2007


Brett,

Ok, I'll bite on a possible solution. Can't for the life of me understand
why you would use RG214 back to the tuner. Two runs??? This isn't balanced.

If you have to, use some of the 450 ohm insulated stuff all the way back to
the tuner. Loops are easy to feed, use coax connected anywhere on the loop;
or use open wire connected anywhere on the loop. Position the loop vertical,
horizontal, low to the ground, high in the air the matchbox should do the
trick. Just cut out the fancy stuff with two runs of coax and or baluns;
they are not needed. Two runs of coax isn't balanced.

I've got a loop in the backyard, horizontal some of it high (20 feet) some
of it low (4 feet) connected somewhere on one side directly to two feed thru
insulators on the shack in the back yard, has about 1-1/2 feet of homebrew
openwire to the junkston KW matchbox; works fine business.

Strange enough; I also got a 40 meter dipole that is sort of diagonally
inside of the 80 meter full wave loop. Matchbox can only get it down to 2:1.
The dipole is feed with 600 ohm HB openwire. Gotta HB ultimate transmatch
that can do about 2KW and will load the dipole.

Matchboxes don't have much range for real strange loads, so get rid of the
two runs of coax. Is there anything in the near field of your loop?

73's
wd8kdg
Craig



-----Original Message-----
From: amradio-bounces at mailman.qth.net
[mailto:amradio-bounces at mailman.qth.net]On Behalf Of Brett gazdzinski
Sent: Monday, January 29, 2007 9:19 AM
To: 'Discussion of AM Radio in the Amateur Service'
Subject: RE: [AMRadio] new antenna and matchbox a bust.



Today I put up about 50 feet each side, up about 35 feet,
fed with 40 feet of open wire line.
Coming into the house I used 2 RG214 runs, with the shields
tied together at the ends, into the Johnson antenna tuner.

A worse working thing I ever put up.
It seems to work real well on receive, but the lowest
swr I was able to get on 80 or 40 was 3 to 1
and even then it acted crazy.

I also tried connection both to the single wire
terminal on the tuner, no go there, worse then ever.

I put my dummy load on the balanced antenna terminals
and it would not tune to a low swr at all.

I wonder how things would work if I left the antenna
at 100 feet and feed it with coax, and used the
heathkit antenna tuner to tune to 80 and 40 meters?

Brett
N2DTS



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