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{KX1} Antenna Matching Question

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stan levandowski

{KX1} Antenna Matching Question

When following the instruction in the KXAT1 manual and using a wire
between 24-28 feet and a 16' counterpoise for 40 and an 8' counterpoise
for 20, the best I can ever get is a 1.6 SWR on 20 and 2.8 SWR on 40.

I've spent lots of time shortening and lengthening wires and writing
down results and I can't hit the magic combination.

The manual also makes it clear on page 8 that a 1:1 SWR is NOT necessary
for good performance. I believe this because the little KX1 makes me
plenty of contacts with this setup, including DX.

I suppose I could just be happy....

However, it bothers me that these SWRs are the best I can do. I don't
like seeing these high ratios on the display. I built this KX1 but had
Don Wilhelm build and install the 30/80 module for me. As part of his
service, he went over my KX1 and told me that it was up to spec.

So my question is: Has any KX1 user out there figured out a wire
length, length and number of counterpoises, etc. that gives a better
match with the KXAT1's capabilities??

When I say I use a wire, I mean I throw it up into a tree and get it as
vertical and possible, then I lay out the counterpoise wires and it all
attaches directly to the KX1 with a dual binding post. Just real
simple!

Thanks for any words of advice and 73,
Stan WB2LQF

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Don Wilhelm

Re: {KX1} Antenna Matching Question

Stan,

Have you tried the 16 foot counterpoise wire on 20 meters.
I don't know, but it is worth a try.

Is your counterpoise wire on the ground? If not, that may be the
difference. A wire on the ground produces a coupling with Mother Earth.
The same wire in the air is just another part of the antenna.

As a fallback, you might want to try something more close to resonance
on 20. A radiator 16 feet long and a radial also 16 feet long. Double
those lengths for 40 meters.

Bruce Prior - a Field Tester for the KX2 had good luck with a 58 foot
radiator and a 13 foot counterpoise wire on the ground for 40 through
10. Although the KX2 ATU has a much greater range than the KX1, it just
may work.

73,
Don W3FPR

On 6/9/2017 4:55 PM, stan levandowski wrote:
> When following the instruction in the KXAT1 manual and using a wire
> between 24-28 feet and a 16' counterpoise for 40 and an 8' counterpoise
> for 20, the best I can ever get is a 1.6 SWR on 20 and 2.8 SWR on 40.
>
> I've spent lots of time shortening and lengthening wires and writing
> down results and I can't hit the magic combination.
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k6dgw

Re: {KX1} Antenna Matching Question

In reply to this post by stan levandowski

I no longer have my KX1 but it got a lot of use when I did. I had the
40/30/20 and KXAT1 options, the 30/80 hadn't been invented when I bought
mine and life is too short for 2.5 watts on 80 anyway. I made an
end-fed wire out of 23 ft [7 m] of RG-58 by:

1. Putting a male BNC on the end

2. Stripping the outer black covering off to within 2 in [~5 cm] of the BNC

3. Pulling the center conductor [still insulated] through the shield
braid at the BNC. This is easily done if you push the braid down to
loosen it and then spread it, kink the center conductor, and push it
through.

When pulled tight without the center conductor, the braid [counterpoise]
will become somewhat longer than the center conductor ... maybe 5-10%.
Wire goes into tree or telescoping mast, braid lays out on the ground.
Tuned SWR on my 3 bands ran around 1.3:1, 20 was often 1:1. The tuned
SWR on 40 was a bit dependent on how I ran the counterpoise in relation
to the antenna, but the effect was small. I seemed to get better on-air
results with the wire sloping from a tree or pole rather than nearly
vertical, but that too was a small effect and probably subjective. I
kept this antenna rolled up on a camp clothesline reel in my KX1 bag.
It went with the KX1 when I sold it.

I used a Buddipole for several years in places where I didn't have to
carry it very far [heavy], but it was touchy to set up and my "recipes"
that worked in the pasture at home never worked at my field sites so
set-up took 30-45 min. I finally switched to a mag loop [Alexloop] on a
sprinkler tripod which works super with my K2.

2:1 isn't terrible considering that you don't have any transmission line
loss. Space limitations in the KX1 dictate that the KXAT1 can have only
a limited number of L-C combos [64?], your match may be in between two
of them.

73,

Fred ["Skip"] K6DGW
Sparks NV DM09dn
Washoe County

On 6/9/17 1:55 PM, stan levandowski wrote:

> When following the instruction in the KXAT1 manual and using a wire
> between 24-28 feet and a 16' counterpoise for 40 and an 8'
> counterpoise for 20, the best I can ever get is a 1.6 SWR on 20 and
> 2.8 SWR on 40.
>
> I've spent lots of time shortening and lengthening wires and writing
> down results and I can't hit the magic combination.
>
> The manual also makes it clear on page 8 that a 1:1 SWR is NOT
> necessary for good performance. I believe this because the little KX1
> makes me plenty of contacts with this setup, including DX.
>
> I suppose I could just be happy....
>
> However, it bothers me that these SWRs are the best I can do. I don't
> like seeing these high ratios on the display. I built this KX1 but
> had Don Wilhelm build and install the 30/80 module for me. As part of
> his service, he went over my KX1 and told me that it was up to spec.
>
> So my question is: Has any KX1 user out there figured out a wire
> length, length and number of counterpoises, etc. that gives a better
> match with the KXAT1's capabilities??
>
> When I say I use a wire, I mean I throw it up into a tree and get it
> as vertical and possible, then I lay out the counterpoise wires and it
> all attaches directly to the KX1 with a dual binding post. Just real
> simple!
>
> Thanks for any words of advice and 73,
> Stan WB2LQF

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stan levandowski

Re: {KX1} Antenna Matching Question

Skip, thanks for your suggestion. It's another option I can try. The
KX1 works just fine with a resonant dipole, vertical with radials, mag
loops, doublet with the BL2, etc. But all these other antennas require
more effort.

The beauty of "just wire" means I can stuff it into my pocket, load the
KX1 up with 8 AA batteries, stick earphones in the other pocket and let
the magic begin!

I have a KX2 for more "Serious" operating!! The (now discontinued) KX1
is just for pure SIMPLE FUN.

Thanks for contributing another idea I can try.

73, Stan WB2LQF

On Fri, Jun 09, 2017 at 06:15 PM, Fred Jensen wrote:

> I no longer have my KX1 but it got a lot of use when I did. I had the
> 40/30/20 and KXAT1 options, the 30/80 hadn't been invented when I
> bought mine and life is too short for 2.5 watts on 80 anyway. I made
> an end-fed wire out of 23 ft [7 m] of RG-58 by:
>
> 1. Putting a male BNC on the end
>
> 2. Stripping the outer black covering off to within 2 in [~5 cm] of
> the BNC
>
> 3. Pulling the center conductor [still insulated] through the shield
> braid at the BNC. This is easily done if you push the braid down to
> loosen it and then spread it, kink the center conductor, and push it
> through.
>
> When pulled tight without the center conductor, the braid
> [counterpoise] will become somewhat longer than the center conductor
> ... maybe 5-10%. Wire goes into tree or telescoping mast, braid lays
> out on the ground. Tuned SWR on my 3 bands ran around 1.3:1, 20 was
> often 1:1. The tuned SWR on 40 was a bit dependent on how I ran the
> counterpoise in relation to the antenna, but the effect was small. I
> seemed to get better on-air results with the wire sloping from a tree
> or pole rather than nearly vertical, but that too was a small effect
> and probably subjective. I kept this antenna rolled up on a camp
> clothesline reel in my KX1 bag. It went with the KX1 when I sold it.
>
> I used a Buddipole for several years in places where I didn't have to
> carry it very far [heavy], but it was touchy to set up and my
> "recipes" that worked in the pasture at home never worked at my field
> sites so set-up took 30-45 min. I finally switched to a mag loop
> [Alexloop] on a sprinkler tripod which works super with my K2.
>
> 2:1 isn't terrible considering that you don't have any transmission
> line loss. Space limitations in the KX1 dictate that the KXAT1 can
> have only a limited number of L-C combos [64?], your match may be in
> between two of them.
>
> 73,
>
> Fred ["Skip"] K6DGW
> Sparks NV DM09dn
> Washoe County
>
> On 6/9/17 1:55 PM, stan levandowski wrote:
>> When following the instruction in the KXAT1 manual and using a wire
>> between 24-28 feet and a 16' counterpoise for 40 and an 8'
>> counterpoise for 20, the best I can ever get is a 1.6 SWR on 20 and
>> 2.8 SWR on 40.
>>
>> I've spent lots of time shortening and lengthening wires and writing
>> down results and I can't hit the magic combination.
>>
>> The manual also makes it clear on page 8 that a 1:1 SWR is NOT
>> necessary for good performance. I believe this because the little
>> KX1 makes me plenty of contacts with this setup, including DX.
>>
>> I suppose I could just be happy....
>>
>> However, it bothers me that these SWRs are the best I can do. I don't
>> like seeing these high ratios on the display. I built this KX1 but
>> had Don Wilhelm build and install the 30/80 module for me. As part
>> of his service, he went over my KX1 and told me that it was up to
>> spec.
>>
>> So my question is: Has any KX1 user out there figured out a wire
>> length, length and number of counterpoises, etc. that gives a better
>> match with the KXAT1's capabilities??
>>
>> When I say I use a wire, I mean I throw it up into a tree and get it
>> as vertical and possible, then I lay out the counterpoise wires and
>> it all attaches directly to the KX1 with a dual binding post. Just
>> real simple!
>>
>> Thanks for any words of advice and 73,
>> Stan WB2LQF
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
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>
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>

Bob McGraw - K4TAX

Re: {KX1} Antenna Matching Question

In reply to this post by stan levandowski

I've never been concerned about a SWR of 3:1 or less on HF. Even with a
3:1 SWR, depending on feed line loss, most of the power is reflected
back to the antenna and is radiated. Now if the length of feedline has
3 dB of loss at the given frequency, then approximately 1/2 of the
reflected power arrives back at the antenna. Hence the reason to use
good to very good low loss feedline.

73

Bob, K4TAX

K3S #10163

On 6/9/2017 3:55 PM, stan levandowski wrote:

> When following the instruction in the KXAT1 manual and using a wire
> between 24-28 feet and a 16' counterpoise for 40 and an 8'
> counterpoise for 20, the best I can ever get is a 1.6 SWR on 20 and
> 2.8 SWR on 40.
>
> I've spent lots of time shortening and lengthening wires and writing
> down results and I can't hit the magic combination.
>
>
> The manual also makes it clear on page 8 that a 1:1 SWR is NOT
> necessary for good performance. I believe this because the little KX1
> makes me plenty of contacts with this setup, including DX.
>
>
> I suppose I could just be happy....
>
>
> However, it bothers me that these SWRs are the best I can do. I don't
> like seeing these high ratios on the display. I built this KX1 but
> had Don Wilhelm build and install the 30/80 module for me. As part of
> his service, he went over my KX1 and told me that it was up to spec.
>
>
> So my question is: Has any KX1 user out there figured out a wire
> length, length and number of counterpoises, etc. that gives a better
> match with the KXAT1's capabilities??
>
>
> When I say I use a wire, I mean I throw it up into a tree and get it
> as vertical and possible, then I lay out the counterpoise wires and it
> all attaches directly to the KX1 with a dual binding post. Just real
> simple!
>
>
> Thanks for any words of advice and 73,
> Stan WB2LQF
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]