I don't think it's whether the line is 300 or 450 vs. 600 ohm that changes the
VF with the weather - it's the dielectric type (plastic etc. vs. air.)
73, Al
On Mon December 29 2014 5:44:53 pm Scott Harwood wrote:
> Thanks, Rick.
>
> I'll get back off the forum about buying the spreaders. I didn't mean to
> imply that weather affected the performance of 450 ohm line, but you
> expressed it much better than I did. It's just that weather causes
> constant re-tuning with 450 or 300 ohm line while 600 ohm line does not.
>
> Always enjoy your comments.
>
> 73
>
> Scott
>
>
> -----Original Message-----
>
> >From: Rick - DJ0IP / NJ0IP <Rick@DJ0IP.de>
> >Sent: Dec 29, 2014 6:02 PM
> >To: 'Discussion of Ten-Tec Equipment' <tentec@contesting.com>
> >Subject: Re: [TenTec] Antenna help
> >
> >Scott,
> >
> >If you need any assistance in placing an order with DX-wire, let me know.
> >I have a business relationship with that company: it is my biggest
> >competitor here in Germany! (hi)
> >But the owner and I are in the same contest club so we're friendly
> >competitors.
> >I buy lots of stuff from him that we don't sell.
> >Peter (the owner) speaks good English.
> >
> >Contrary to a lot of what you read, snow and ice build-up does not have a
> >huge impact on performance, it just changes the velocity factor of the
> >window line and requires you to re-tune your matchbox. After that it will
> >work fine - until the snow thaws and you must retune again.
> >
> >In contests, re-tuning matchboxes due to changing wx is something I try to
> >avoid. Therefore I take the time to build my own feedline for home use.
> >But for portable, it's just so much easier working with the window line.
> >
> >73 - Rick, DJ0IP
> >(Nr. Frankfurt am Main)
> >
> >
> >-----Original Message-----
> >From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of Scott
> >Harwood
> >Sent: Monday, December 29, 2014 11:51 PM
> >To: Discussion of Ten-Tec Equipment
> >Subject: Re: [TenTec] Antenna help
> >
> >
> >Rick:
> >
> >Thanks for the info on the open wire spreaders. My supplier of 600 ohm
> >parallel line recently passed away and his company has been shut down.
> > I'll try your www.dx-wire.de site. The spreaders look very nice. I
> > totally concur with your comments on the 450 ohm (or even 300 ohm)
> > twinlead line. I've found that rain, snow, ice, etc. affect that type of
> > plastic coated line much more than the 600 ohm line.
> >
> >73
> >
> >Scott K4VWK
> >
> >-----Original Message-----
> >
> >>From: Rick - DJ0IP / NJ0IP <Rick@DJ0IP.de>
> >>Sent: Dec 29, 2014 4:52 PM
> >>To: 'Discussion of Ten-Tec Equipment' <tentec@contesting.com>
> >>Subject: Re: [TenTec] Antenna help
> >>
> >>Curron,
> >>
> >>As with all similar questions, you will need to give us more
> >>information before we answer.
> >>
> >>Jim's answer might be right but it might not be.
> >>It all depends on several factors.
> >>
> >>Up front, my opinion of this antenna is, if I could have just one
> >>antenna for the rest of my life, this is exactly the antenna I would
> >>choose. IMO, no other antenna covers so many bands in so many
> >>directions as well as this antenna.
> >>
> >>Scott's article is excellent. I strongly recommend you download and
> >>read it. Pay particular attention to what he says about antenna
> >>tuners. There is a lot of mis-information floating around about how to
> >>match openwire fed antennas. Without a doubt, a symmetrical tuner is
> >>by far the best way to go.
> >>If you are going to run more than a couple hundred watts, it's the only
> >>way to go.
> >>Otherwise you may find yourself up to your antlers in
> >> common-mode-current.
> >>
> >>If you use an asymmetrical tuner, it is much better to use a 1:1 balun
> >>than a 4:1 balun - even if you have to play with feedline lengths.
> >>This assumes you have a fairly decent ATU. Most auto-tuners won't work
> >
> >here.
> >
> >>If you must use an asymmetrical tuner and want to run high power AND
> >>your matchbox won't get by without a 4:1 balun, then you must insert a
> >>1:1 Guanella between the matchbox and the 4:1 balun. Otherwise you may
> >>find yourself up to your antlers in CMC.
> >>
> >>450 Ohm windowline (i.e. Wireman) will work and is what I usually use
> >>for portable work, but for home use it is better to build your own
> >
> >openwire.
> >
> >>Use spreaders that snap in place; something like this:
> >> http://www.73cnc.com/product_p/ls250.htm
> >>
> >>My favorite (by far) are here:
> >>http://www.dx-wire.de/lng/en/huehnerleiter-spreizer/?language=en
> >>They come in 4 different widths. He will ship to stateside.
> >>
> >>I have seen a couple other similar products in the states.
> >>Don't fool with spreaders where you must thread the wires through the
> >
> >holes.
> >
> >>You'll end up as crazy as me.
> >>
> >>Curron, here are some questions:
> >>>> What bands do you intend to work with this antenna? (list them all,
> >>
> >>don't just say other bands)
> >>
> >>>> Will this be your only antenna? If not, list the others you have or
> >>>> plan
> >>
> >>to have.
> >>
> >>>> When working 80m with this antenna, is your main interest DX? Or do
> >>>> you
> >>
> >>wish to rag chew all around the states?
> >>
> >>>> Which antenna tuner were you planning on using (make and model) How
> >>>> much power will you be running.
> >>
> >>Again, if at all possible, you should use a symmetrical matchbox.
> >>There aren't a lot of these on the market.
> >>I have compiled a fairly comprehensive list on my web, divided into low
> >>power and high power matchboxes.
> >>
> >>> www.dj0ip.de/antenna-matchboxes/symmetrical-matchboxes/low-power-atu-
> >>> s/
> >>> www.dj0ip.de/antenna-matchboxes/symmetrical-matchboxes/high-power-atu
> >>> -s/
> >>
> >>If you can find an old Johnson Viking Matchbox (either the 275w or
> >>Kilowatt version), I strongly recommend installing the modification I
> >>show on my web
> >>site:
> >>www.dj0ip.de/antenna-matchboxes/symmetrical-matchboxes/j-viking-upgrade
> >>/ This will significantly improve its matching range and provide a
> >>better match on several bands.
> >>
> >>In summary, if you are looking for an @ss-kicking DX antenna for 80, as
> >>Jim said, there are better antennas.
> >>But if you're looking for a good performing omni-directional antenna on
> >>80 that will also work well on all other bands, this one is perfect for
> >>the job.
> >>
> >>73 - Rick, DJ0IP
> >>(Nr. Frankfurt am Main)
> >>
> >>
> >>-----Original Message-----
> >>From: TenTec [mailto:tentec-bounces@contesting.com] On Behalf Of Curron
> >>Sent: Monday, December 29, 2014 7:51 PM
> >>To: tentec@contesting.com
> >>Subject: [TenTec] Antenna help
> >>
> >>
> >>
> >>Need some help folks...
> >>
> >>I would like to get some input on building an 80 meter sky loop antenna
> >>that I will use on 80 and other bands with an antenna tuner. I have
> >>some nice tall pine trees to run the corners to and I plan on joining
> >>the loop to the house with 450 ohm ladder line. Just under the edge of
> >>the house I will install a balun and bring it into the house with low
> >>loss coax. Please make any comments or offer any advice you can. I am
> >>hoping to learn from your experiences. Some questions I have are:
> >>
> >>- What kind of wire should I use for the loop antenna
> >>
> >>- What type of rope that will hold up to the UV and time (so much just
> >>falls apart these days)
> >>
> >>- What balun, 4:1, 1:1 ?
> >>
> >>- Is 450 ohm feed ladder line the best to use? This part will be about
> >>80 feet long. Will this length be a problem?
> >>
> >>- Has anyone ever had any issues using
> >>delrin for the insulators? Is there a better?
> >>
> >>- I am thinking about placing a screen door spring on each corner to
> >>allow the trees to sway in the wind. anyone ever tried that. Or should
> >>I just counter weight to opposing corners of the loop?
> >>
> >>- How's the best way to protect this
> >>setup from lightning?
> >>
> >>Thanks in advance for any help!
> >>
> >>
> >>
> >>73
> >>
> >>Don kb3drw
> >>
> >>
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