[Elecraft] wire antennas
David Wilburn
dave.wilburn at verizon.net
Wed Feb 21 09:46:29 EST 2007
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
dave.wilburn at verizon.net
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" <w3fpr at earthlink.net>
> Subject: RE: [Elecraft] wire antennas
> To: "David Wilburn" <dave.wilburn at verizon.net>,
> <elecraft at mailman.qth.net>
> Message-ID: <NGEDLJLDCGJIHEGPMIJPMEPGGEAA.w3fpr at earthlink.net>
> 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
>> dave.wilburn at verizon.net
>> 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" <mpitts at suite224.net>
> Subject: Re: [Elecraft] Custom K2?
> To: Bob Nielsen <nielsen at oz.net>
> Cc: Elecraft <elecraft at mailman.qth.net>
> Message-ID: <45DBCEB2.5080700 at suite224.net>
> 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: Elecraft at mailman.qth.net
>> 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" <ehrlich at olypen.com>
> Subject: Re: [Elecraft] wire antennas
> To: "David Wilburn" <dave.wilburn at verizon.net>,
> <elecraft at mailman.qth.net>
> Message-ID: <006501c75579$be442810$c0d8c141 at 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" <dave.wilburn at verizon.net>
> To: <elecraft at mailman.qth.net>
> 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
>> dave.wilburn at verizon.net
>> K4DGW
>>
>>
>> _______________________________________________
>> Elecraft mailing list
>> Post to: Elecraft at mailman.qth.net
>> 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" <oaxaca at oregoncoast.com>
> Subject: [Elecraft] twin lead not just HF
> To: <elecraft at mailman.qth.net>
> Message-ID: <002b01c75579$f1981c30$66960ed0 at 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 <elecraft at astromag.co.uk>
> Subject: [Elecraft] K1 frequency drift observations
> To: elecraft at mailman.qth.net
> Message-ID: <45DBEF15.5050804 at astromag.co.uk>
> 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
>
>
> ------------------------------
>
> _______________________________________________
> Elecraft mailing list
> Post to: Elecraft at mailman.qth.net
> http://mailman.qth.net/mailman/listinfo/elecraft
> You must be a subscriber to post.
> Elecraft web page: http://www.elecraft.com
>
> End of Elecraft Digest, Vol 34, Issue 23
> ****************************************
>
>
> _______________________________________________
> Elecraft mailing list
> Post to: Elecraft at mailman.qth.net
> 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
>
More information about the Elecraft
mailing list