It seems that Curt tried everything with the feed line. However, it would
appear he did nothing to assure that the load was balanced. That being the
case, yes a balanced line with an unbalanced load will have asymmetrical
currents and thus radiation will occur from the feed line. Same true for a
coaxial line with an improper termination.
73
Bob, K4TAX
----- Original Message -----
From: "NJ0IP" <Rick@DJ0IP.de>
To: "'Discussion of Ten-Tec Equipment'" <tentec@contesting.com>
Sent: Saturday, July 09, 2005 7:29 AM
Subject: Re: [TenTec] "Radiates like Crazy"???? No
> OK Curt, you don't have to respond, but I wish to.
>
> Question: How do you put up a single antenna that should cover ALL bands
> reasonably well, and feed it with coax? Please keep in mind that my
> linear
> is transistorized and requires a good SWR.
>
> I accept everything you say as being the truth - in the situations you
> guys
> tried it. There is no question, sometimes RF takes strange ways.
>
> I have a neighbor about 5 doors down who was wiping out his own TV
> although
> he was only running 100w.
> We replaced his coax with open wire (ladderline) and used a matchbox and
> the
> TVI was gone. He also claims to get out much better now. Prior to that
> he
> had tried all sorts of things like low-pass filters, better ground, etc.
>
> I don't think this is a matter of being an old timer vs. being new to the
> game. That has nothing to do with it. I guess I'm an old timer, though I
> don't feel like it. All my gear is very modern (Orion plus Henry Solid
> State Linear Amp and lots of computers) and I also have about 300 meters
> of
> high quality coax which I use to feed beams or verticals when I go on my
> contest expeditions. I have a choice at home to use either coax or
> openwire.
>
> Here at home I'm challenged by not being able to put up as many antennas
> as
> I would like and a tower is out of the question. My XYL and neighbors
> agreed to one antenna. I sort of hid a second (vertical) antenna between
> the trees and got away with it. I feed both antennas with openwire so
> that
> I can run them on all bands. They work great and I pretty much hold my
> own
> in contests and working DX. I'm not sure how I could accomplish this
> using
> coax.
>
> I run 750w, our legal limit in Germany, and I don't have any interference
> in
> the TV, Radio, or telephone.
>
> And finally, "My dog eats Kennel Ration too." :-)
>
> 73
> Rick
> DJ0IP
>
> -----Original Message-----
> From: tentec-bounces@contesting.com [mailto:tentec-bounces@contesting.com]
> On Behalf Of Curt
> Sent: Saturday, July 09, 2005 4:44 AM
> To: Discussion of Ten-Tec Equipment
> Subject: Re: [TenTec] "Radiates like Crazy"???? No
>
> I love it when what happened to me and several others
> mostly at W3KHW a ham radio club in Pittsburgh is
> dismissed as silly nonsensical rubbish. I tried
> everything mentioned here to solve the problem:
> Twisting. Lengthening and shorting the feed length.
> Match boxes. Balun and no balun. Making sure it didn't
> touch anything. Making sure it had no sharp bends.
> Wrapping it in circles. Straightening it. Name it and
> it was tried via advice from all the old timers at
> W3KHW. So finally coax was purchased and problem was
> solved instantly. This is why I stated ladder line
> radiates like crazy because it sure as hell did in my
> situation and several others at W3KWH. Call me stupid,
> misinformed, insane or whatever does it for you, it
> doesn't matter because I know what ladder provided me
> and a few others, nothing but nightmares of RFI and
> TVI to my neighbors who lived very close to me back
> then. The other guys had problems with it getting into
> their homes with RF flying around the house causing
> family members to complain. I don't care if you have
> been using ladder for 60 years! For me and a few of
> my friends it was nothing but headaches. Coax on the
> extreme other hand was very unforgiving and "never"
> radiated no matter the configuration applied to it
> unlike ladder line. Funny how the old timers are the
> ones who use ladder line, it's not something that is
> wildly popular these days and neither are the big
> bands and Frank Sinatra on the top 40 charts anymore,
> they are a distant memory. Distance as in light years.
> I will no longer respond to this subject because it's
> only vanity going back and forth ad nauseam and for
> what? Mine is bigger than yours..don't think so.
>
>
> Love Curt
>
> --- NJ0IP <Rick@DJ0IP.de> wrote:
>
>> I fully agree with Stuart. Curt must have made some
>> strange experience to
>> cause him to feel that way.
>>
>> Ladderline does not radiate like crazy - hardly at
>> all - if the load at both
>> ends are symmetrical. Stuart's tip about twisting
>> it is highly recommended.
>>
>> I've used openwire for over 40 years and the
>> ladderline since about 20 years
>> now. I have often had cases of it radiating.
>> Specifically, nearly every
>> time I tried to feed it thru a balun in front of an
>> asymmetrical matchbox.
>> I don't care which side of the matchbox you place
>> the balun, it still did
>> not eliminate this radiation - especially when
>> running a linear.
>>
>> I have also had at a truly symmetrical matchbox
>> (Annecke) for the past 25
>> years and each time I had the problem above, I
>> solved it by using my
>> symmetrical matchbox instead of the jerry-rigged
>> solution described above
>> (and still sold by many vendors as "a symmetrical
>> solution"). Lesson
>> learned. There are no shortcuts in life and quality
>> costs money.
>>
>> In the meantime I have 4 symmetrical matchboxes with
>> various power ratings
>> and I run legal power here and don't have any
>> problems with feedline
>> radiation.
>>
>> Coax radiates too if it has high SWR on it
>> (everybody knows that and knows
>> how to fix it).
>> Open wire feedline radiates when either of its ends
>> are not in balance (keep
>> it in balance and it won't radiate).
>> These are rules of thumb.
>> Of course there are rare exceptions to every rule,
>> but the statement that
>> ladderline radiates like crazy is blatantly wrong!
>>
>> Using ladderline or homebrew openwire is an
>> excellent way to build a simple,
>> effective wire antenna which will operate all (or
>> most) bands.
>>
>> If anyone is interested in using openwire /
>> ladderline feedline but wasn't
>> sure how to feed it, here is some useful
>> information:
>>
>> In the meantime there are good symmetrical
>> matchboxes available for all
>> sorts of power level. The are at least 5 or 6
>> vendors offering excellent
>> products for a reasonable price. A recent ARRL
>> (QST) article described some
>> of these, but only focused on the U.S. vendors (MFJ,
>> Palstar). There are
>> alse several European vendors with great products
>> too (e.g., U.K. Amp,
>> Hamware, Christian (DL3LAC), and DL1SWR). Just be
>> sure the box you are
>> interested in is truly symmetrical. MFJ and Palstar
>> both make good and bad
>> products advertised as suitable for symmetrical.
>>
>> 73
>> Rick
>>
>>
>> -----Original Message-----
>> From: tentec-bounces@contesting.com
>> [mailto:tentec-bounces@contesting.com]
>> On Behalf Of Curt
>> Sent: Friday, July 08, 2005 11:45 AM
>> To: Discussion of Ten-Tec Equipment
>> Subject: Re: [TenTec] "Radiates like Crazy"???? No
>>
>> I don't care if you do or don't...you're
>> wrong!!!!!!!!!!
>>
>> --- Stuart Rohre <rohre@arlut.utexas.edu> wrote:
>>
>> > I must respectfully disagree that ladder line
>> > "radiates like crazy".
>> >
>> > It is BALANCED line, that means if it is fed from
>> a
>> > balanced source and goes
>> > to a balanced antenna, the currents are equal and
>> > opposite in each wire and
>> > their fields cancel within a few diameters of the
>> > line. See the theory of
>> > transmission lines in the ARRL Handbooks.
>> >
>> > It should cross conductors at right angles, and
>> > should be twisted every 18
>> > inches or so, to minimize effects from nearby
>> > conductors that could
>> > unbalance it.
>> >
>> > If you ever have ladder line "radiating" you are
>> mis
>> > applying it in some way
>> > at one end or the other. Balanced antennas are
>> > center fed beams, dipoles,
>> > etc. with line brought off at 90 degrees to the
>> > antenna wires.
>> >
>> > Let's bury these old wive's tales about balanced
>> > parallel transmission
>> > lines.
>> >
>> > Stuart
>> > K5KVH
>> >
>> >
>> >
>> > _______________________________________________
>> > TenTec mailing list
>> > TenTec@contesting.com
>> >
>> http://lists.contesting.com/mailman/listinfo/tentec
>> >
>>
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