It seems that for local 40M daytime chatter, the EFHW kicks the vertical's butt.
To the tune of 3 or 4 S units reported.
- Jerry, KF6VB
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On 2025-03-01 15:49, jerry-KF6VB wrote:
OK, it's fixed.
I had a gigantic 31-mix core that I'd been saving for a rainy day. FT400-31.
Ordered some RG400 to make a choke, but looking at that core - I figured I
could do it with RG-8. And so I did. 12 turns. Took some real pulling and
grabbing.
No more feedback.
- Jerry, KF6VB
On 2025-02-28 16:56, K9HZ wrote:
Thats what line feed chokes are specifically made for. One on each
end of the feedline.
DR. WILLIAM J. SCHMIDT - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ
PJ2/K9HZ
Owner - Operator
Big Signal Ranch ¨C K9ZC
Staunton, Illinois
Owner ¨C Operator
Villa Grand Piton - J68HZ
Soufriere, St. Lucia W.I.
Rent it: www.VillaGrandPiton.com
email: bill@...
On Feb 28, 2025, at 5:59?PM, Larry Acklin via groups.io
<acklin@...> wrote:
?
I used to have issues with my FT901 like that, CW would stick in
transmit- RF in the shack. A ferrite slug with 6 wraps of the
shielded CW key lead after it left the external keyer fixed it.
My EFHW starts at 30 ft and slopes to 10, counterpoise drops to 6 ft
and runs along roughly the same route. 40, 20, 15, 10 all acceptable
SWR. 49:1 balun feeds coax to the radio.
Larry
KB3CUF
On Fri, Feb 28, 2025 at 2:57?PM jerry-KF6VB via groups.io [1]
<jerry@...> wrote:
Hello all,
I was trying out my station with a second antenna - an 65-foot
End
Fed Half Wave. I had built it to the kilowatt level, with a big
toroid
core on the matching transformer. Instead of a counterpoise, I
used an
8-foot ground rod - the kind they sell to ground your house.
Probably needs a counterpoise also...
The far end of the antenna is supported by a monster oak tree
on my
property. Got it up there with a slingshot.
I hooked up a spare MFJ998RT autotuner to the EFHW and thence
to my
station through
a 40-foot length of Davis Buryflex RG/8.
It worked fine on the base T41 - decent SWR on 40, 20 & 15M.
And it
actually worked
on 80 - although the autotuner was clearly struggling.
HOWEVER, when I turned on my KW amp, I pushed the PTT, and the
power
immediately rose to 950W or so out...without me talking. And
somebody
on the frequency said "what's that noise?".
I figure that RF is getting back into the T41.
Probably need to stick a counterpoise on the EFHW, and maybe a
common
mode choke.
My main antenna does not give me any such problems; it's a
trap
vertical up the hill,
and it has an excellent ground - an Ufer ground, consisting of 80
feet
of thick copper wire embedded in a 10 by 70' concrete slab.
I'm trying the EFHW to see if it's any quieter than my
vertical. So
far, it's about the same.
- Jerry, KF6VB
Links:
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[1]
[2] /g/SoftwareControlledHamRadio/message/33004
[3] /mt/111440976/243852
[4] /g/SoftwareControlledHamRadio/post
[5] /g/SoftwareControlledHamRadio/editsub/243852
[6]
/g/SoftwareControlledHamRadio/leave/10484476/243852/1943518115/xyzzy
