TheRadioBoard

Hello,

Does anyone with more experience then me have experience using this for an antenna for crystal radios?

http://www.homedepot.com/p/5-32-in-x-10 ... W_-FdeiURA

Seems like it would be awesome for a random wire antenna in the back yard as its built for the outdoors.

Thanks,

David Cole

I'm reasonably sure the stranded wire inside is steel, which is a lot stronger and cheaper than copper, but conducts electricity poorly compared to copper.

The insulated, stranded copper wire sold for home electrical wiring is supposed to work fairly well.

For some extra money you can better buy some real litz antenna wire as used by HAM`s for their longwire/FD3/FD4, or whatever wire antenna they use.
I use stranded litz wire for my x-tal radio antenna, 2x20mtrs in parallel, one meter from eachother. Looks still great after about 10yrs outside in the elements.
The wire is also coated with some transparant plastic.

Just my thoughts
73
Frank

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www.pa2mrx.nl

I've never used Litz for an antenna. I think it's not worth the expense. Home Depot sells 14-gauge single-conductor copper wire for about the same price as that clothesline. That's what I'd use. I've made a lot of antennas with the stuff. It will stretch a little initially, but not much. If you use a spring or a bucket of rocks (with holes in the bucket so water doesn't collect) as a counterweight, the far tree can sway around and the wire won't break.

73,

Jim

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http://kr1s.kearman.com/
http://qrp.kearman.com/

Frank,could you elaborate on the "stranded litz" wire construction.
Approximate strand count,are the strands individually insulated
from each other, size etc.?

Eb

Thanks for the responses guys. I was just looking for something cheap.

KR1S - I wondered about how to deal with tree sway when its windy. I figured if it was attached solidly a guy could leave a little slack, but it might slack a lot if the wind is blowing the tree the opposite way.

Should the lead-in be as short as possible? The best way for me to throw the antenna up is to string it from the back of my house out to a tree, but then the only place in the house to have my radio is downstairs in the front of the house. The lead-in may be the same length or more than the antenna.

David Cole

I use 1m of bungee (same as I use when sailing), it copes quite nicely with sway.
It actualy stayed up this winter despite hurricane force winds, it started the storm ice covered (guess how long ice clung on), the tree lost quite few branches though.
OH, antenna is a inverted L made out of 2.5mm² stranded PVC insulated.

I guess as long as the tree sway doesn't exceed the length a bungee cord can stretch, it would be okay. The pail of rocks works until the line to the pail breaks! There's a saying that, if your antenna stays up all winter it isn't big enough.

The feedline has to be what it is. If it's as long as the antenna it will be part of the antenna. Assuming the feedline is going through the house, not over it, try to keep it as far as possible from power wiring to reduce noise pickup.


73,

Jim

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http://kr1s.kearman.com/
http://qrp.kearman.com/

Thanks guys, that makes a new guy feel better.

Eb,

I use this antenna wire for my x-tal sets and transceiver.

http://www.classicinternational.eu/kabel/antennelitze/antennelitze-7x7x0-2-mm-gecoat/

Don`t know about the individual insulation. It`s in the air for some years now and I don`t got a piece lying to see.

73
Frank

_________________
www.pa2mrx.nl

Thanks Frank,I sent an inquiry to Classicinternational,and just received their
reply:
"Hi Eberhard, (sounds German?)



Thank you for your enquiry. The antenna wire, manufactured in Germany , has 7 x 7 individual bare copper wires. Outside coated/insulated.



Small packs we usually send by airmail. Do you want us to quote for 50 meters incl. P&P ?



Best regards,
Joe Vaartjes, PA0JOP

International Sales & Marketing

ClassicInternational"


This confirms my expectation that "Litze" is used in the german
language meaning "stranded wire" in general,while "Litz" as used in
this forum,and in english radio/electronic texts has the much
narrower meaning of "HF-Litze" in your part of the world.
I just thought it might be useful information for some readers here.

Eb.

I agree with KR1S. In 50+ years in ham radio, I have never used Litz wire for an antenna. Litz, as we use the word, is great stuff for winding coils in the BC band, but I don't see any advantage in using it for an antenna.

Most hams use stranded or solid copper wire, or sometimes "Copperweld" which is copper-clad steel.

http://www.davisrf.com/antenna-wire/

In my opinion, conductivity is not a major issue for a receiving antenna. The current is so low...

But, I am the guy who had a full-length 160 meter dipole back in W3-land... made from Sears galvanized electric fence wire. It was about $20 for quarter MILE spool. That's about 400 meters, I think. Worked well for me with 100 Watts of SSB. Transmitting melted the ice off the antenna in winter. I suspect the rather high resistance allowed me to load it on 160 with a bandwidth of about 120 KHz. Maybe it was a little bit of an antenna and mainly a resistive "dummy load."

Rich

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Homebrew Radio ex-Silicon Valley