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Tierra del Mar Labs

twin lead not just HF

Aloha to all,

I joined this list a month ago to ask a question about an xv222 that had
a bad crystal. Since then, the most fascinating threads abound here
most, stretching far from Elecraft matters. Cool!

I would like to state that I am no expert to balanced feed lines but
reading here, I must state how forgiving this medium is.

I use twin lead for my arrays, 144 thru 1296, splice this and that,
solder blobs, different wire sizes, whatever. All my micro wave and
vhf/uhf stuff comes over 400 feet back to the house at 28 and 14 MHz
IF's, simple 600 Ohm tiwn lead built open air style on short utility
poles. This stuff is so forgiving and to the uhf and up enthusiast, Much
quieter than coax.

Kind'a like the Bi-Polar and the FET in the first days of the
transistor....who made the mistake of going the Bi-Polar way anyway, we
must have lost 20 years of technology to this.

I'm for twin lead, and strip lines. Tnx fer a fun list!

73 Jeremy w7eme

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dave.wilburn

Re: wire antennas

In reply to this post by Don Wilhelm-3

Yea, that is what has been keeping me away from 160m. I have several on
going projects, and I can't start one of that magnitude now. Might have
room for a dipole, so will just have to try that. Once I order some
ladder line.

David Wilburn
[hidden email]

Don Wilhelm wrote:

> Dave,
>
> As far as switching your loop to a 160 top loaded vertical, yes you can do
> it remotely with relays and a matching network. If your goal is efficiency
> on 160 meters, the relay switching os only a small part of the equation -
> you must have a good RF ground for the vertical to work against, and that
> menas lots of wires in the ground, radiating from the base of the antenna.
> Some will tell you tht 120 radials will give optimum performance, but 16 or
> more will give great performance as well. If the radials are buried, the
> length is not critical, lots of short buried radials will do almost as good
> as a moderate number of long ones - see the 160 meter antenna simulation
> results that are outlined on L B Cebik's website www.cebik.com. More
> information on low band antennas can be found in ON4UN's Low Band DXing
> book - there are many possibilities.
>
> For best results, put the 160 meter matching network at the base of the
> antenna and match it to your feedline.
>
> Since there are many possibilities, make some decision even though it may be
> a compromise and you too can be successful on 'top-band'.
>
> 73,
> Don W3FPR
>
>
>> -----Original Message-----
>>
>> I am very much enjoying reading the discussions on wire antennas. I
>> have something I have been trying to figure out how to do for some time,
>> and thought this might be a good place to ask.
>>
>> I have an 80m loop, up about 60 or 70 feet. Currently it is fed with
>> 300 ohm line. All I could find at the time, as what I had left in 450
>> ohm line (after I helped my elderly neighbor get his antenna back up,
>> and gave him some of the ladder line) was not long enough.
>> Additionally, I went to the local hamfest this weekend and could not
>> find a single vendor selling ladder line, but I digress. I have
>> approximately 290 feet of wire in the air in a horizontal, triangular
>> configuration, fed with (soon to be) ladder line, a balun (1:1) and then
>> coax to the shack. Is it possible to switch this (seems possible from
>> what I have read) to a 160m antenna by taking one side to ground at the
>> balun and feeding the other side? If this is possible, is there a way
>> to do this remotely?
>>
>> David Wilburn
>> [hidden email]
>> K4DGW
>>
> --
> No virus found in this outgoing message.
> Checked by AVG Free Edition.
> Version: 7.5.441 / Virus Database: 268.18.3/694 - Release Date: 2/20/2007
> 1:44 PM
>
>

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dave.wilburn

Re: wire antennas

In reply to this post by Don Ehrlich-2

Yes, and it doesn't work. This is the second 80m horizontal loop I have
had, and they just do not like going low.

David Wilburn
[hidden email]

Don wrote:

> Have you tried using the antenna on 160 through a tuner just as it is?
> Chances are you can match it even on 160M and if you do you will not
> have to worry about the ground losses you would have feeding it against
> ground (unless using lots of radials).
>
> Don K7FJ
>
> ----- Original Message ----- From: "David Wilburn"
> <[hidden email]>
> To: <[hidden email]>
> Sent: Tuesday, February 20, 2007 8:07 PM
> Subject: Re: [Elecraft] wire antennas
>
>
>> I am very much enjoying reading the discussions on wire antennas. I
>> have something I have been trying to figure out how to do for some
>> time, and thought this might be a good place to ask.
>>
>> I have an 80m loop, up about 60 or 70 feet. Currently it is fed with
>> 300 ohm line. All I could find at the time, as what I had left in 450
>> ohm line (after I helped my elderly neighbor get his antenna back up,
>> and gave him some of the ladder line) was not long enough.
>> Additionally, I went to the local hamfest this weekend and could not
>> find a single vendor selling ladder line, but I digress. I have
>> approximately 290 feet of wire in the air in a horizontal, triangular
>> configuration, fed with (soon to be) ladder line, a balun (1:1) and
>> then coax to the shack. Is it possible to switch this (seems possible
>> from what I have read) to a 160m antenna by taking one side to ground
>> at the balun and feeding the other side? If this is possible, is
>> there a way to do this remotely?
>>
>> David Wilburn
>> [hidden email]
>> K4DGW
>>
>>
>> _______________________________________________
>> Elecraft mailing list
>> Post to: [hidden email]
>> You must be a subscriber to post to the list.
>> Subscriber Info (Addr. Change, sub, unsub etc.):
>> http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/subscribers.htm
>> Elecraft web page: http://www.elecraft.com
>
>

Rick Hiller

RE: wire antennas

In reply to this post by wsm-3

Dave,

Another possibility for 160 -- Don't know to what extent/effort you want to
go to get on 160, but here is an easy way, although, a bit of a compromise.

Simply open the loop at one of the 80 meter voltage loops (also a current
node). The 80 meter standing wave current distribution /performance will
not change, but it will force the wire to be an off center fed 1/2
wavelength for 160. Although not quite resonant within the 160 meter band,
if you feed it with open wire and run it thru the appropriate matching
network, you should be right.

Quite possibly, if you adjust your overall length you might be able to find
a length that is 1 wl on 80 where you need it and 1/2 wl on 160 close to
where you want to work. Have a look at this in EZNEC to see how it will
work for you in your particular situation. I use this method to run 80 on
my 40 meter delta loop.

It is a lot easier than relays and switches, but Don's good suggestion might
be the preferred solution for you.

GL...Rick -- W5RH

Date: Tue, 20 Feb 2007 23:47:33 -0500
From: "Don Wilhelm" <[hidden email]>
Subject: RE: [Elecraft] wire antennas
To: "David Wilburn" <[hidden email]>,
<[hidden email]>
Message-ID: <[hidden email]>
Content-Type: text/plain; charset="iso-8859-1"

Dave,

As far as switching your loop to a 160 top loaded vertical, yes you can do
it remotely with relays and a matching network. If your goal is efficiency
on 160 meters, the relay switching os only a small part of the equation -
you must have a good RF ground for the vertical to work against, and that
menas lots of wires in the ground, radiating from the base of the antenna.
Some will tell you tht 120 radials will give optimum performance, but 16 or
more will give great performance as well. If the radials are buried, the
length is not critical, lots of short buried radials will do almost as good
as a moderate number of long ones - see the 160 meter antenna simulation
results that are outlined on L B Cebik's website www.cebik.com. More
information on low band antennas can be found in ON4UN's Low Band DXing
book - there are many possibilities.

For best results, put the 160 meter matching network at the base of the
antenna and match it to your feedline.

Since there are many possibilities, make some decision even though it may be
a compromise and you too can be successful on 'top-band'.

73,
Don W3FPR

> -----Original Message-----
>
> I am very much enjoying reading the discussions on wire antennas. I
> have something I have been trying to figure out how to do for some time,
> and thought this might be a good place to ask.
>
> I have an 80m loop, up about 60 or 70 feet. Currently it is fed with
> 300 ohm line. All I could find at the time, as what I had left in 450
> ohm line (after I helped my elderly neighbor get his antenna back up,
> and gave him some of the ladder line) was not long enough.
> Additionally, I went to the local hamfest this weekend and could not
> find a single vendor selling ladder line, but I digress. I have
> approximately 290 feet of wire in the air in a horizontal, triangular
> configuration, fed with (soon to be) ladder line, a balun (1:1) and then
> coax to the shack. Is it possible to switch this (seems possible from
> what I have read) to a 160m antenna by taking one side to ground at the
> balun and feeding the other side? If this is possible, is there a way
> to do this remotely?
>
> David Wilburn
> [hidden email]
> K4DGW
>

--
No virus found in this outgoing message.
Checked by AVG Free Edition.
Version: 7.5.441 / Virus Database: 268.18.3/694 - Release Date: 2/20/2007
1:44 PM

------------------------------

Message: 2
Date: Tue, 20 Feb 2007 23:46:42 -0500
From: "Matthew D. Pitts" <[hidden email]>
Subject: Re: [Elecraft] Custom K2?
To: Bob Nielsen <[hidden email]>
Cc: Elecraft <[hidden email]>
Message-ID: <[hidden email]>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

So tempting... I haven't fiddled with Linux in a few years and might be
able to scrounge up a PC to run it on (I think all I'm missing for a
working system amongst the parts I have is a power supply).

Bob Nielsen wrote:

>
> On Feb 20, 2007, at 3:32 PM, Ian Stirling wrote:
>
>> On Tuesday 20 February 2007 18:19, you wrote:
>>
>>> Rig control software for people who use "real" computers (Fedora Core
>>> here). http://www.hamsoftware.org/ Haven't used it, but saw your
>>> comment and did a quick google. This is the first one I ran across,
>>> may
>>> be others. Are you on Mac or Linux? Because there were quite a few
>>> choices for Mac also.
>>
>> Multiplexing myself between my kubuntu/gnu/linux computer
>> and cooking cream of scallion soup. I've recently switched
>> to kubuntu from FreeBSD 6.1.
>
> There are a lot of good ham apps suitable for use with a K2 that are
> in the repositories for Ubuntu (and I assume kubuntu and xubuntu as
> well; they are all Debian derivatives): hamlib, gmfsk, xlog, tlf, to
> name a few I have used.
>
> 73 - Bob, N7XY
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
> http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com
>

------------------------------

Message: 3
Date: Tue, 20 Feb 2007 21:32:55 -0800
From: "Don" <[hidden email]>
Subject: Re: [Elecraft] wire antennas
To: "David Wilburn" <[hidden email]>,
<[hidden email]>
Message-ID: <006501c75579$be442810$c0d8c141@Don>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
reply-type=response

Have you tried using the antenna on 160 through a tuner just as it is?
Chances are you can match it even on 160M and if you do you will not have to

worry about the ground losses you would have feeding it against ground
(unless using lots of radials).

Don K7FJ

----- Original Message -----
From: "David Wilburn" <[hidden email]>
To: <[hidden email]>
Sent: Tuesday, February 20, 2007 8:07 PM
Subject: Re: [Elecraft] wire antennas

>I am very much enjoying reading the discussions on wire antennas. I have
>something I have been trying to figure out how to do for some time, and
>thought this might be a good place to ask.
>
> I have an 80m loop, up about 60 or 70 feet. Currently it is fed with 300
> ohm line. All I could find at the time, as what I had left in 450 ohm
> line (after I helped my elderly neighbor get his antenna back up, and gave

> him some of the ladder line) was not long enough. Additionally, I went to
> the local hamfest this weekend and could not find a single vendor selling
> ladder line, but I digress. I have approximately 290 feet of wire in the
> air in a horizontal, triangular configuration, fed with (soon to be)
> ladder line, a balun (1:1) and then coax to the shack. Is it possible to
> switch this (seems possible from what I have read) to a 160m antenna by
> taking one side to ground at the balun and feeding the other side? If
> this is possible, is there a way to do this remotely?
>
> David Wilburn
> [hidden email]
> K4DGW
>
>
> _______________________________________________
> Elecraft mailing list
> Post to: [hidden email]
> You must be a subscriber to post to the list.
> Subscriber Info (Addr. Change, sub, unsub etc.):
> http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/subscribers.htm
> Elecraft web page: http://www.elecraft.com

------------------------------

Message: 4
Date: Wed, 21 Feb 2007 05:34:22 -0000
From: "Tierra del Mar Labs" <[hidden email]>
Subject: [Elecraft] twin lead not just HF
To: <[hidden email]>
Message-ID: <002b01c75579$f1981c30$66960ed0@S0031935242>
Content-Type: text/plain; charset="us-ascii"

Aloha to all,

I joined this list a month ago to ask a question about an xv222 that had
a bad crystal. Since then, the most fascinating threads abound here
most, stretching far from Elecraft matters. Cool!

I would like to state that I am no expert to balanced feed lines but
reading here, I must state how forgiving this medium is.

I use twin lead for my arrays, 144 thru 1296, splice this and that,
solder blobs, different wire sizes, whatever. All my micro wave and
vhf/uhf stuff comes over 400 feet back to the house at 28 and 14 MHz
IF's, simple 600 Ohm tiwn lead built open air style on short utility
poles. This stuff is so forgiving and to the uhf and up enthusiast, Much
quieter than coax.

Kind'a like the Bi-Polar and the FET in the first days of the
transistor....who made the mistake of going the Bi-Polar way anyway, we
must have lost 20 years of technology to this.

I'm for twin lead, and strip lines. Tnx fer a fun list!

73 Jeremy w7eme

------------------------------

Message: 5
Date: Wed, 21 Feb 2007 07:04:53 +0000
From: Dave G4AON <[hidden email]>
Subject: [Elecraft] K1 frequency drift observations
To: [hidden email]
Message-ID: <[hidden email]>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

When I built my K1 back in 2002 (serial 1154), I opted to use the
supplied 68 pF capacitor at C2. I found the drift figures worse than the
specification and changed the "NP0" ceramic capacitor for a polystyrene
one. The drift was just under 200 Hz per hour, while meeting
specification (just) it was always an irritation and noticeable on most
QSOs.

Looking at the problem with a little more science than emotion, it
appeared the drift was caused by too much negative temperature
coefficient (i.e. too much "polystyrene") and I replaced the 68 pF
capacitor with a local purchase ceramic one of zero temperature
coefficient one (I wonder if the one I fitted originally wasn't really
an NP0 type). The overall result, in a fairly stable room temperature,
is a drift of roughly 100 Hz per hour. The K2 drifts in an LF direction
when operating on 7 MHz, which seems to be the direction of drift for
others I've come across.

The frequency drift was measured with an external counter and "off air"
frequency standard. Over a two hour period the drift was lower in
frequency by 198 Hz, yet the display on the K1 didn't indicate any
frequency movement! In the past others and I have noticed a tendency for
the displayed frequency to "jump", usually by 200 Hz, especially when
using the CAL function after swapping band boards, using the RIT/XIT and
similar large and fast frequency changes. It would appear that slow
drift is not registering on the K1 display... Am I seeing things or is
this really the case? My assumption is the code is written to damp down
frequency display changes to avoid a flickering last digit, but appears
to result in a frozen display that can fool us into thinking a K1 is not
drifting when in reality it is.

Any thoughts?

Dave, G4AON

------------------------------

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End of Elecraft Digest, Vol 34, Issue 23
****************************************

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dave.wilburn

Re: wire antennas

In reply to this post by wsm-3

If I disconnected one side of the loop from balun, at that point (at
least from what I have looked at on the web) it is similar to an
inverted L with the wire wondering around instead of going off in one
direction like it should. At that point, an inverted L would need
radials. Problem is, this is right at the back side of my house, there
is a deck and then an above ground pool. So looking at it from above, I
could only get radials on about a 90 degree portion. Seems like a lot
of trouble to go to for such a small foot print.

I had originally hoped to put enough wire in the air for a 160m loop,
but my best estimates put me about 100 ft too short.

David Wilburn
[hidden email]

Dale Putnam wrote:

> I would be wanting to try to utilize it as a top loaded vertical, tie
> the twinlead feeder together, then treat it as a vertical on 160.
> The loop as a loop presents tuff to match situation for most tuners.
> They just run out of capability at that low end. You might try moving
> the length of feedline with a set of coils, one in each lead, you may be
> able to move the match enough using the length of feedline to help the
> tuner get into a working situation.
> Worth the effort tho. That should work nicely and let you hear well too.
>
> --... ...-- Dale - WC7S in Wy
>
>
>
>
> ------------------------------------------------------------------------
> Discover the new Windows Vista Learn more!
> <http://search.msn.com/results.aspx?q=windows+vista&mkt=en-US&form=QBRE>

dave.wilburn

Re: wire antennas

In reply to this post by Rick Hiller

Not sure where you are suggesting I open it. I was considering
disconnecting the feedline on one side where it connected to the balun.
Is this what you mean. My apologies if it is a silly question.

David Wilburn
[hidden email]

Rick Hiller wrote:

> Dave,
>
> Another possibility for 160 -- Don't know to what extent/effort you want to
> go to get on 160, but here is an easy way, although, a bit of a compromise.
>
> Simply open the loop at one of the 80 meter voltage loops (also a current
> node). The 80 meter standing wave current distribution /performance will
> not change, but it will force the wire to be an off center fed 1/2
> wavelength for 160. Although not quite resonant within the 160 meter band,
> if you feed it with open wire and run it thru the appropriate matching
> network, you should be right.
>
> Quite possibly, if you adjust your overall length you might be able to find
> a length that is 1 wl on 80 where you need it and 1/2 wl on 160 close to
> where you want to work. Have a look at this in EZNEC to see how it will
> work for you in your particular situation. I use this method to run 80 on
> my 40 meter delta loop.
>
> It is a lot easier than relays and switches, but Don's good suggestion might
> be the preferred solution for you.
>
> GL...Rick -- W5RH
>
>
> Date: Tue, 20 Feb 2007 23:47:33 -0500
> From: "Don Wilhelm" <[hidden email]>
> Subject: RE: [Elecraft] wire antennas
> To: "David Wilburn" <[hidden email]>,
> <[hidden email]>
> Message-ID: <[hidden email]>
> Content-Type: text/plain; charset="iso-8859-1"
>
> Dave,
>
> As far as switching your loop to a 160 top loaded vertical, yes you can do
> it remotely with relays and a matching network. If your goal is efficiency
> on 160 meters, the relay switching os only a small part of the equation -
> you must have a good RF ground for the vertical to work against, and that
> menas lots of wires in the ground, radiating from the base of the antenna.
> Some will tell you tht 120 radials will give optimum performance, but 16 or
> more will give great performance as well. If the radials are buried, the
> length is not critical, lots of short buried radials will do almost as good
> as a moderate number of long ones - see the 160 meter antenna simulation
> results that are outlined on L B Cebik's website www.cebik.com. More
> information on low band antennas can be found in ON4UN's Low Band DXing
> book - there are many possibilities.
>
> For best results, put the 160 meter matching network at the base of the
> antenna and match it to your feedline.
>
> Since there are many possibilities, make some decision even though it may be
> a compromise and you too can be successful on 'top-band'.
>
> 73,
> Don W3FPR
>
>
>> -----Original Message-----
>>
>> I am very much enjoying reading the discussions on wire antennas. I
>> have something I have been trying to figure out how to do for some time,
>> and thought this might be a good place to ask.
>>
>> I have an 80m loop, up about 60 or 70 feet. Currently it is fed with
>> 300 ohm line. All I could find at the time, as what I had left in 450
>> ohm line (after I helped my elderly neighbor get his antenna back up,
>> and gave him some of the ladder line) was not long enough.
>> Additionally, I went to the local hamfest this weekend and could not
>> find a single vendor selling ladder line, but I digress. I have
>> approximately 290 feet of wire in the air in a horizontal, triangular
>> configuration, fed with (soon to be) ladder line, a balun (1:1) and then
>> coax to the shack. Is it possible to switch this (seems possible from
>> what I have read) to a 160m antenna by taking one side to ground at the
>> balun and feeding the other side? If this is possible, is there a way
>> to do this remotely?
>>
>> David Wilburn
>> [hidden email]
>> K4DGW
>>
> --
> No virus found in this outgoing message.
> Checked by AVG Free Edition.
> Version: 7.5.441 / Virus Database: 268.18.3/694 - Release Date: 2/20/2007
> 1:44 PM
>
>
>
> ------------------------------
>
> Message: 2
> Date: Tue, 20 Feb 2007 23:46:42 -0500
> From: "Matthew D. Pitts" <[hidden email]>
> Subject: Re: [Elecraft] Custom K2?
> To: Bob Nielsen <[hidden email]>
> Cc: Elecraft <[hidden email]>
> Message-ID: <[hidden email]>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> So tempting... I haven't fiddled with Linux in a few years and might be
> able to scrounge up a PC to run it on (I think all I'm missing for a
> working system amongst the parts I have is a power supply).
>
> Bob Nielsen wrote:
>> On Feb 20, 2007, at 3:32 PM, Ian Stirling wrote:
>>
>>> On Tuesday 20 February 2007 18:19, you wrote:
>>>
>>>> Rig control software for people who use "real" computers (Fedora Core
>>>> here). http://www.hamsoftware.org/ Haven't used it, but saw your
>>>> comment and did a quick google. This is the first one I ran across,
>>>> may
>>>> be others. Are you on Mac or Linux? Because there were quite a few
>>>> choices for Mac also.
>>> Multiplexing myself between my kubuntu/gnu/linux computer
>>> and cooking cream of scallion soup. I've recently switched
>>> to kubuntu from FreeBSD 6.1.
>> There are a lot of good ham apps suitable for use with a K2 that are
>> in the repositories for Ubuntu (and I assume kubuntu and xubuntu as
>> well; they are all Debian derivatives): hamlib, gmfsk, xlog, tlf, to
>> name a few I have used.
>>
>> 73 - Bob, N7XY
>> _______________________________________________
>> Elecraft mailing list
>> Post to: [hidden email]
>> You must be a subscriber to post to the list.
>> Subscriber Info (Addr. Change, sub, unsub etc.):
>> http://mailman.qth.net/mailman/listinfo/elecraft
>> Help: http://mailman.qth.net/subscribers.htm
>> Elecraft web page: http://www.elecraft.com
>>
>
>
>
> ------------------------------
>
> Message: 3
> Date: Tue, 20 Feb 2007 21:32:55 -0800
> From: "Don" <[hidden email]>
> Subject: Re: [Elecraft] wire antennas
> To: "David Wilburn" <[hidden email]>,
> <[hidden email]>
> Message-ID: <006501c75579$be442810$c0d8c141@Don>
> Content-Type: text/plain; format=flowed; charset="iso-8859-1";
> reply-type=response
>
> Have you tried using the antenna on 160 through a tuner just as it is?
> Chances are you can match it even on 160M and if you do you will not have to
>
> worry about the ground losses you would have feeding it against ground
> (unless using lots of radials).
>
> Don K7FJ
>
> ----- Original Message -----
> From: "David Wilburn" <[hidden email]>
> To: <[hidden email]>
> Sent: Tuesday, February 20, 2007 8:07 PM
> Subject: Re: [Elecraft] wire antennas
>
>
>> I am very much enjoying reading the discussions on wire antennas. I have
>> something I have been trying to figure out how to do for some time, and
>> thought this might be a good place to ask.
>>
>> I have an 80m loop, up about 60 or 70 feet. Currently it is fed with 300
>> ohm line. All I could find at the time, as what I had left in 450 ohm
>> line (after I helped my elderly neighbor get his antenna back up, and gave
>
>> him some of the ladder line) was not long enough. Additionally, I went to
>> the local hamfest this weekend and could not find a single vendor selling
>> ladder line, but I digress. I have approximately 290 feet of wire in the
>> air in a horizontal, triangular configuration, fed with (soon to be)
>> ladder line, a balun (1:1) and then coax to the shack. Is it possible to
>> switch this (seems possible from what I have read) to a 160m antenna by
>> taking one side to ground at the balun and feeding the other side? If
>> this is possible, is there a way to do this remotely?
>>
>> David Wilburn
>> [hidden email]
>> K4DGW
>>
>>
>> _______________________________________________
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>
>
>
> ------------------------------
>
> Message: 4
> Date: Wed, 21 Feb 2007 05:34:22 -0000
> From: "Tierra del Mar Labs" <[hidden email]>
> Subject: [Elecraft] twin lead not just HF
> To: <[hidden email]>
> Message-ID: <002b01c75579$f1981c30$66960ed0@S0031935242>
> Content-Type: text/plain; charset="us-ascii"
>
> Aloha to all,
>
> I joined this list a month ago to ask a question about an xv222 that had
> a bad crystal. Since then, the most fascinating threads abound here
> most, stretching far from Elecraft matters. Cool!
>
> I would like to state that I am no expert to balanced feed lines but
> reading here, I must state how forgiving this medium is.
>
> I use twin lead for my arrays, 144 thru 1296, splice this and that,
> solder blobs, different wire sizes, whatever. All my micro wave and
> vhf/uhf stuff comes over 400 feet back to the house at 28 and 14 MHz
> IF's, simple 600 Ohm tiwn lead built open air style on short utility
> poles. This stuff is so forgiving and to the uhf and up enthusiast, Much
> quieter than coax.
>
> Kind'a like the Bi-Polar and the FET in the first days of the
> transistor....who made the mistake of going the Bi-Polar way anyway, we
> must have lost 20 years of technology to this.
>
> I'm for twin lead, and strip lines. Tnx fer a fun list!
>
> 73 Jeremy w7eme
>
>
>
> ------------------------------
>
> Message: 5
> Date: Wed, 21 Feb 2007 07:04:53 +0000
> From: Dave G4AON <[hidden email]>
> Subject: [Elecraft] K1 frequency drift observations
> To: [hidden email]
> Message-ID: <[hidden email]>
> Content-Type: text/plain; charset=ISO-8859-1; format=flowed
>
> When I built my K1 back in 2002 (serial 1154), I opted to use the
> supplied 68 pF capacitor at C2. I found the drift figures worse than the
> specification and changed the "NP0" ceramic capacitor for a polystyrene
> one. The drift was just under 200 Hz per hour, while meeting
> specification (just) it was always an irritation and noticeable on most
> QSOs.
>
> Looking at the problem with a little more science than emotion, it
> appeared the drift was caused by too much negative temperature
> coefficient (i.e. too much "polystyrene") and I replaced the 68 pF
> capacitor with a local purchase ceramic one of zero temperature
> coefficient one (I wonder if the one I fitted originally wasn't really
> an NP0 type). The overall result, in a fairly stable room temperature,
> is a drift of roughly 100 Hz per hour. The K2 drifts in an LF direction
> when operating on 7 MHz, which seems to be the direction of drift for
> others I've come across.
>
> The frequency drift was measured with an external counter and "off air"
> frequency standard. Over a two hour period the drift was lower in
> frequency by 198 Hz, yet the display on the K1 didn't indicate any
> frequency movement! In the past others and I have noticed a tendency for
> the displayed frequency to "jump", usually by 200 Hz, especially when
> using the CAL function after swapping band boards, using the RIT/XIT and
> similar large and fast frequency changes. It would appear that slow
> drift is not registering on the K1 display... Am I seeing things or is
> this really the case? My assumption is the code is written to damp down
> frequency display changes to avoid a flickering last digit, but appears
> to result in a frozen display that can fool us into thinking a K1 is not
> drifting when in reality it is.
>
> Any thoughts?
>
> Dave, G4AON
>
>
> ------------------------------
>
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>
> End of Elecraft Digest, Vol 34, Issue 23
> ****************************************
>
>
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>

Leigh L. Klotz Jr WA5ZNU

Re: twin lead not just HF

Administrator

In reply to this post by Tierra del Mar Labs

There is a book called Crustal Fier about the invention of the
transistor. In it, I read that Shockley wanted to make an FET, but
Brattain and Bardeen, working for him, semi-secretly switched to working
on a point-contact device which was easier to get working. As a result,
Brattain's name was left off the patent, leading to a bitter rift which,
aided by personality, eventually lead to the dissolution of Shockley
Transistor and the mutiny of a eight scientists who in 1957 started the
fair-headed stepchild company, which they called Fairchild
Semiconductor. Two of the founders of Fairchild, Robert Noyce and Gordon
Moore, left to found Intel, giving us semiconductor memory and
microprocessors.

So, while we may have lost 20 years due to the frustrations of working
with BJT over FET, the ensuing currents moved many others to fulfill
their potentials.

The rest of the story is even more detailed and nuanced...Crystal Fire,
the Birth of the Information Age.
Leigh/WA5ZNU
On Tue, 20 Feb 2007 9:34 pm, Tierra del Mar Labs wrote:
> Kind'a like the Bi-Polar and the FET in the first days of the
> transistor....who made the mistake of going the Bi-Polar way anyway, we
> must have lost 20 years of technology to this.

> 73 Jeremy w7eme
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N2EY

Re: wire antennas

In reply to this post by dave.wilburn

-----Original Message-----
From: [hidden email]

If I disconnected one side of the loop from balun, at that point (at
least from what I have looked at on the web) it is similar to an
inverted L with the wire wondering around instead of going off in one
direction like it should. At that point, an inverted L would need
radials. Problem is, this is right at the back side of my house, there
is a deck and then an above ground pool. So looking at it from above, I
could only get radials on about a 90 degree portion. Seems like a lot
of trouble to go to for such a small foot print.

---

Sounds to me like the loop is up in the air and the feedline drops down
to near the ground, right outside the house. It then goes
into a balun, and coax runs from the balun into the shack. Hope that's
right.

If so, what I would do is this:

1) Disconnect *both* wires of the feedline from the balun. Tie them
together.

2) Disconnect coax from balun

3) Connect an unbalanced tuner (simple L network?) between balun and
the two feedline wires which are tied together.

4) Connect ground system to tuner

5) Adjust tuner for minimum SWR

In such a system the vertical feedline does much of the radiating. The
loop does some, and also acts as a sort of top-hat loading. The main
benefit is the feedpoint Z

Of course you need a ground system, and the pool/deck are in the way.
So run the wires and rods that you can. Better than nothing.

If it were me, I'd try this out temporarily (wires on top of ground,
tuner in a plastic bag to keep the weather off, etc.) just to see how
it works. If it seemed OK, then I'd do a permanent system with relays,
remote-control tuner, buried radials, etc., when the weather improves.

73 de Jim, N2EY

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Don Wilhelm-3

RE: wire antennas

In reply to this post by dave.wilburn

Dave,

Open it at the point 180 degrees (midway around) from the feedpoint. If
your existing loop is a full wavelength on 80 meters, opening it will turn
the loop into a folded back 1/2 wave dipole on 160 meters - not as good as
straight out, but it should work since you are feeding the line with a tuner
anyway.
In fact, you may be able to make it automatic by using a trap tuned to 160
meters - that will electrically open the loop on 160 and only add some
inductnce on the other bands.

73,
Don W3FPR

> -----Original Message-----

>
> Not sure where you are suggesting I open it. I was considering
> disconnecting the feedline on one side where it connected to the balun.
> Is this what you mean. My apologies if it is a silly question.
>
> David Wilburn
> [hidden email]
>
>
>
> Rick Hiller wrote:
> > Dave,
> >
> > Another possibility for 160 -- Don't know to what extent/effort
> you want to
> > go to get on 160, but here is an easy way, although, a bit of a
> compromise.
> >
> > Simply open the loop at one of the 80 meter voltage loops (also
> a current
> > node). The 80 meter standing wave current distribution
> /performance will
> > not change, but it will force the wire to be an off center fed 1/2
> > wavelength for 160. Although not quite resonant within the 160
> meter band,
> > if you feed it with open wire and run it thru the appropriate matching
> > network, you should be right.
> >
>

--
No virus found in this outgoing message.
Checked by AVG Free Edition.
Version: 7.5.441 / Virus Database: 268.18.3/694 - Release Date: 2/20/2007
1:44 PM

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dave.wilburn

Re: wire antennas

That is definitely getting interesting. So I want to block 160m from
going through, but pass 80m and above. Does that sound do able? With
the number of people that run horizontal loops you would think this
would be going on more.

David Wilburn
[hidden email]

Don Wilhelm wrote:

> Dave,
>
> Open it at the point 180 degrees (midway around) from the feedpoint. If
> your existing loop is a full wavelength on 80 meters, opening it will turn
> the loop into a folded back 1/2 wave dipole on 160 meters - not as good as
> straight out, but it should work since you are feeding the line with a tuner
> anyway.
> In fact, you may be able to make it automatic by using a trap tuned to 160
> meters - that will electrically open the loop on 160 and only add some
> inductnce on the other bands.
>
> 73,
> Don W3FPR
>
>> -----Original Message-----
>
>> Not sure where you are suggesting I open it. I was considering
>> disconnecting the feedline on one side where it connected to the balun.
>> Is this what you mean. My apologies if it is a silly question.
>>
>> David Wilburn
>> [hidden email]
>>
>>
>>
>> Rick Hiller wrote:
>>> Dave,
>>>
>>> Another possibility for 160 -- Don't know to what extent/effort
>> you want to
>>> go to get on 160, but here is an easy way, although, a bit of a
>> compromise.
>>> Simply open the loop at one of the 80 meter voltage loops (also
>> a current
>>> node). The 80 meter standing wave current distribution
>> /performance will
>>> not change, but it will force the wire to be an off center fed 1/2
>>> wavelength for 160. Although not quite resonant within the 160
>> meter band,
>>> if you feed it with open wire and run it thru the appropriate matching
>>> network, you should be right.
>>>
> --
> No virus found in this outgoing message.
> Checked by AVG Free Edition.
> Version: 7.5.441 / Virus Database: 268.18.3/694 - Release Date: 2/20/2007
> 1:44 PM
>
>

Stuart Rohre

Re: wire antennas

In reply to this post by dave.wilburn

How low did you have your horizontal loop? We always use a 2 wave or so one
for field day, (80m), but mostly use it on 40m and up to 15m. It is always
only 20 feet high, as that is the limit of reach of our portable ladder.

We get great signal reports, and work all over the country from the Central
Southwest.

I have seen an 80m loop work less well than a dipole when low to a roof
containing a metal edging, which we put off to detuning and coupling issues.
We feed our loops with parallel lines, either 300 ohm window or 450 ohm
window line.

Stuart
K5KVH

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Stuart Rohre

Re: wire antennas

In reply to this post by Mike Morrow-3

Mike and the group,
I am currently routing heavy duty 300 ohm twin lead from a 5/8 leg 20m
antenna, thru a slot cut into some foam pipe insulation that acts as a panel
in the bottom of a aluminum sash window. The window has aluminum sill, and
frame, and individual panes of glass with aluminum sub frames. Cross the
metal at right angle does not affect the normal operation of my B&W tuner,
and I am using the internal balun of this tuner and getting normal loading,
and good signal reports with only 20 watts SSB, from the rig I use.

If you cross at right angles and twist the feeder outside along its run,
interaction with conductors is minimized and balance is preserved adequately
for use with the tuner.

Stuart
K5KVH

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dave.wilburn

Re: wire antennas

In reply to this post by Stuart Rohre

After contemplating it a bit, I would say that it is 75 to 80 feet up.
I had a similar one at my previous house up about 90 feet. It worked
great. I broke more than one pileup while barefoot. I'm hoping this
one works better after I get some 450 ohm ladder line on it. The both
have tuned very well on the major bands, and with a bit of a struggle on
some like 30m. The automatic antenna tuners in the my rigs has always
worked pretty well tuning them up.

David Wilburn
[hidden email]

Stuart Rohre wrote:

> How low did you have your horizontal loop? We always use a 2 wave or so one
> for field day, (80m), but mostly use it on 40m and up to 15m. It is always
> only 20 feet high, as that is the limit of reach of our portable ladder.
>
> We get great signal reports, and work all over the country from the Central
> Southwest.
>
> I have seen an 80m loop work less well than a dipole when low to a roof
> containing a metal edging, which we put off to detuning and coupling issues.
> We feed our loops with parallel lines, either 300 ohm window or 450 ohm
> window line.
>
> Stuart
> K5KVH
>
>
>