Elecraft

Re: Elecraft] KX2

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k6dgw

Re: Elecraft] KX2

I use an EFHW on 80-10, no dedicated counterpoise, no coax length rqmts. However, NEC2 doesn't like a source at the open end of a wire so to model it, I have to put some counterpoise on the wire. Length not critical, 5-10 ft is fine.

73,

Fred K6DGW

David Gilbert <[hidden email]> wrote:

>
>I'm confused why an EFHW should need a counterpoise. If it needs a
>counterpoise it isn't actually acting like an EFHW. If it needs a
>counterpoise that means there isn't enough choking impedance at the
>feedpoint, and it means that the feedline is radiating with the
>counterpoise acting as ... well, a counterpoise.
>
>Manufacturers state a minimum length feedline simply to have the
>feedline losses help swamp out SWR variations along the line, and of
>course to marginally lower the SWR.
>
>Dave
>AB7E
>
>
>On 7/14/2016 1:03 PM, Don Wilhelm wrote:
>> Andy,
>>
>> What happens if you connect to a dummy load? Does the KX2 tune it
>> properly?
>> If so, then you know the KX2 is operating into a 50 ohm load OK.
>>
>> Do you have an antenna analyzer? If so, then connect it to the
>> antenna feedline and look at the impedance - both real and reactive -
>> as well as the SWR.
>> That will tell you whether the antenna is troublesome.
>>
>> You specifically said an EFHW - that should be a resonant antenna. If
>> instead you have a random length wire (not a halfwave), and what is
>> the matching device?
>> Many EFHW antennas need a counterpoise to work - that is why many
>> manufacturers state a *minimum* length feedline.
>>
>> If the problem is *not* the antenna, contact Elecraft support.
>>
>> 73,
>> Don W3FPR
>>
>> On 7/14/2016 2:40 PM, Andy Clift wrote:
>>> Just received my KX2, but unable to get it to tune an EFHW wire. I’ve
>>> tried a home made one and then tried a SOTABEAMS MultiBander that
>>> I’ve used successfully with an FT-857. I’ve checked the continuity in
>>> the wire and also the continuity in the KX2 between the BNC connector
>>> and where the wire connects inside the KX2 (as I removed this to fit
>>> the end panels). Battery is at over 11v. Any ideas please?
>>>
>>> ______________________________________________________________
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>>
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Jim Brown-10

Re: Elecraft] KX2

On Thu,7/14/2016 2:54 PM, Fred C. Jensen wrote:
> I use an EFHW on 80-10, no dedicated counterpoise, no coax length rqmts.

On what frequency is it a halfwave? :)

73, Jim

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k6dgw

Re: Elecraft] KX2

In reply to this post by k6dgw

80. KAT3 will match it on 160, haven't tried to make any Q's there yet. Works great everywhere else considering it's strung on the 6' fence.
Fred K6DGWTDY in Socal (softball)

Sent from my Verizon 4G LTE smartphone

-------- Original message --------
From: Jim Brown <[hidden email]>
Date: 7/14/16 20:41 (GMT-08:00)
To: [hidden email]
Subject: Re: [Elecraft] Elecraft] KX2

On Thu,7/14/2016 2:54 PM, Fred C. Jensen wrote:
> I use an EFHW on 80-10, no dedicated counterpoise, no coax length rqmts.

On what frequency is it a halfwave? :)

73, Jim

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David Gilbert

Re: Elecraft] KX2

By "works great" I assume you mean it loads well, which is
understandable since a horizontal wire 6 feet off the ground is going to
look pretty lossy.

Dave AB7E

On 7/14/2016 10:17 PM, k6dgw wrote:

>
> 80. KAT3 will match it on 160, haven't tried to make any Q's there yet. Works great everywhere else considering it's strung on the 6' fence.
> Fred K6DGWTDY in Socal (softball)
>
>
> Sent from my Verizon 4G LTE smartphone
>
> -------- Original message --------
> From: Jim Brown <[hidden email]>
> Date: 7/14/16 20:41 (GMT-08:00)
> To: [hidden email]
> Subject: Re: [Elecraft] Elecraft] KX2
>
> On Thu,7/14/2016 2:54 PM, Fred C. Jensen wrote:
>> I use an EFHW on 80-10, no dedicated counterpoise, no coax length rqmts.
> On what frequency is it a halfwave? :)
>
> 73, Jim
>
> ______________________________________________________________
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Charlie T, K3ICH

Re: Elecraft] KX2

In reply to this post by Jim Brown-10

One other question I have concerns the length of these "EFHW" antennas that
many are using.
That is, are they REALLY End Fed Half-Waves? In other words, are they cut
to be an electrical half wave-length or, are they simply a convenient
length of wire, that is fed at one end?
There could be a drastic difference in the feed point impedance depending
on this parameter.

Also, what's wrong with making a true "Zepp" antenna on the higher bands by
adding the required length of twin lead for the ¼λ matching section? On
20 M and up, this would result in a fairly easy length of wire to deal with.

Anybody tried that approach? I know the "J-Poles" are popular on VHF, but
how about a 20 meter wire J-Pole?

73, Charlie k3ICH

-----Original Message-----
From: Elecraft [mailto:[hidden email]] On Behalf Of Jim
Brown
Sent: Thursday, July 14, 2016 11:42 PM
To: [hidden email]
Subject: Re: [Elecraft] Elecraft] KX2

On Thu,7/14/2016 2:54 PM, Fred C. Jensen wrote:
> I use an EFHW on 80-10, no dedicated counterpoise, no coax length rqmts.

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Phil Wheeler-2

Re: Elecraft] KX2

There is a terminology issue, Charlie. The "EFHW"
I use is this one:
http://www.earchi.org/92011endfedfiles/Endfed6_40.pdf
and is fed via a 9:1 UN-UN. Uses the coax shield
as a counterpoise and seems to work well over the
bands of interest -- depending on the length of
wire used. An ATU is generally essential, and the
one in the KX2 is very capable.

Phil W7OX

On 7/15/16 5:34 AM, Charlie T, K3ICH wrote:

> One other question I have concerns the length of these "EFHW" antennas that
> many are using.
> That is, are they REALLY End Fed Half-Waves? In other words, are they cut
> to be an electrical half wave-length or, are they simply a convenient
> length of wire, that is fed at one end?
> There could be a drastic difference in the feed point impedance depending
> on this parameter.
>
> Also, what's wrong with making a true "Zepp" antenna on the higher bands by
> adding the required length of twin lead for the ¼λ matching section? On
> 20 M and up, this would result in a fairly easy length of wire to deal with.
>
> Anybody tried that approach? I know the "J-Poles" are popular on VHF, but
> how about a 20 meter wire J-Pole?
>
> 73, Charlie k3ICH
>
>
> -----Original Message-----
> From: Elecraft [mailto:[hidden email]] On Behalf Of Jim
> Brown
> Sent: Thursday, July 14, 2016 11:42 PM
> To: [hidden email]
> Subject: Re: [Elecraft] Elecraft] KX2
>
> On Thu,7/14/2016 2:54 PM, Fred C. Jensen wrote:
>> I use an EFHW on 80-10, no dedicated counterpoise, no coax length rqmts.

Don Wilhelm

Re: Elecraft] KX2

The terminology is very *important* for clarity in what you are talking
about - especially in the field of antennas where many classic names
have been modified so that there is no longer any meaning in the name -
I pointed this out in reference to the number of antennas referred to as
a Zepp.

For instance, the "EFHW" referred to below is *not* an EFHW, but an end
fed random wire (look at the description).
The "HW" part refers to "halfwave", and a halfwave radiator has specific
charactistics. Its behavior is different than feeding a wire of random
length.

So please, lets call things by their proper names so we all can
understand each other when we are communicating. Failure to call things
by their proper designation leads to communications chaos.
If you mean a real end fed halfwave, please tell us what band it is
resonant on and what the matching device is. If you have a non-resonant
end fed wire, please tell us how long it is and tell us what the
matching device is. By that means, we can all understand each other
more clearly.

73,
Don W3FPR

On 7/15/2016 10:31 AM, Phil Wheeler wrote:
> There is a terminology issue, Charlie. The "EFHW" I use is this one:
> http://www.earchi.org/92011endfedfiles/Endfed6_40.pdf and is fed via a
> 9:1 UN-UN. Uses the coax shield as a counterpoise and seems to work
> well over the bands of interest -- depending on the length of wire
> used. An ATU is generally essential, and the one in the KX2 is very
> capable.
>

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Don Wilhelm

Re: Elecraft] KX2

In reply to this post by Charlie T, K3ICH

Charlie,

There is nothing wrong with making a true Zepp antenna for any band - we
usually refer to them as a J-Pole that is popular at VHF/UHF.
Use 300 ohm transmission line for the 1/4 wave matching section.
See the works of Gary O'Neil N3GO on J-poles for discussion of the ideal
characteristic impedance of the matching section. See
http://www.knightlites.org/n3go_workshop/N3GO_JPole.xls for a worksheet
to give you all the details.

Your J-Pole does not have to be oriented vertically - it will work as a
horizontal antenna or a sloper. It can be bent between the radiator and
the matching section.

73,
Don W3FPR

On 7/15/2016 8:34 AM, Charlie T, K3ICH wrote:
> Also, what's wrong with making a true "Zepp" antenna on the higher bands by
> adding the required length of twin lead for the ¼λ matching section? On
> 20 M and up, this would result in a fairly easy length of wire to deal with.
>
> Anybody tried that approach? I know the "J-Poles" are popular on VHF, but
> how about a 20 meter wire J-Pole?
>

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Henry Pollock - K4TMC

Re: Elecraft] KX2

In reply to this post by Charlie T, K3ICH

For a 20M J-Pole look at N1LO's web page -
http://www.qsl.net/n1lo/antenna.htm

I have used his 10M collinear super J-Pole for years in my HOA-neighborhood
back yard hanging from tall tree limbs. For the last 2 years it has been
supported by a 55 ft fiberglass mast. It is my year-round go-to antenna
for checking conditions on 10M.

73,
Henry Pollock - K4TMC

On Fri, Jul 15, 2016 at 8:34 AM, Charlie T, K3ICH <[hidden email]> wrote:

> One other question I have concerns the length of these "EFHW" antennas that
> many are using.
> That is, are they REALLY End Fed Half-Waves? In other words, are they cut
> to be an electrical half wave-length or, are they simply a convenient
> length of wire, that is fed at one end?
> There could be a drastic difference in the feed point impedance depending
> on this parameter.
>
> Also, what's wrong with making a true "Zepp" antenna on the higher bands by
> adding the required length of twin lead for the ¼λ matching section? On
> 20 M and up, this would result in a fairly easy length of wire to deal
> with.
>
> Anybody tried that approach? I know the "J-Poles" are popular on VHF, but
> how about a 20 meter wire J-Pole?
>
> 73, Charlie k3ICH
>
>
> -----Original Message-----
> From: Elecraft [mailto:[hidden email]] On Behalf Of Jim
> Brown
> Sent: Thursday, July 14, 2016 11:42 PM
> To: [hidden email]
> Subject: Re: [Elecraft] Elecraft] KX2
>
> On Thu,7/14/2016 2:54 PM, Fred C. Jensen wrote:
> > I use an EFHW on 80-10, no dedicated counterpoise, no coax length rqmts.
>
>
>
> ______________________________________________________________
> 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]