HF longwire ant question

[cbadie]

Hi, I am going to try and move my HF antenna from inside the attic to outside. I could string it under the eaves which would make for a good length. Question is whether the longwire could have some bends in it to run the full length of the house? My back facing part of the house is not in a straight line.

Thank you

 

[NDRADIONUT]

Bending is fine....

 

[ka3jjz]

Up to a point. Never bend an antenna back upon itself- you may run into weird effects with cancelling nodes.

It would be much better if you can get that antenna away from the home as much as possible to remove the effects of picking up local noise sources within your home. But not everyone has that luxury, I know.

That being said, this really isn't a longwire - that's a different breed of antenna that's at least 1 wavelength long, and is mounted close to the ground. This is more of a random wire than anything else.

Mike

 

[majoco]

The back part of my house is not a straight line either - so I used TV antenna masts and strung a wire between them with an RF transformer at the feed point. The middle mast was used to hang a discone and a UHF antenna on as well - right above my 'playroom'!

http://forums.radioreference.com/at...15904-my-property-jamesdale-antenna-1-sml.jpg

 

[cmdrwill]

Mount the 'longwire' on standoff's to get it away from the roof a little bit.

 

[cbadie]

Thanks all. IF I bend it would be around a corner at most.

I am thinking about trying out the PAR-EF SWL antenna, which seems to get good remarks. It also has an impedance matching device which I do not have now.

Getting the antenna out of the attic HAS to help, don't you think? Not sure how far away from the eaves I will be able to work it (HOA). Also, from what I can tell orienting the antenna wire N - S seems preferred over E- W...is that what others have experienced? I live in Arizona.

 

[ridgescan]

Before I got a Wellbrook loop, I ran a 100' endfed wire along the east and north sides of my building, with a non-conductive wooden 10'dowel as a turning point midway and another one at the far end to terminate. RF cannot see that bend, it just sees 100' wire. I actually kind of miss that antenna-it was very good.

 

[ka3jjz]

Thanks all. IF I bend it would be around a corner at most.

I am thinking about trying out the PAR-EF SWL antenna, which seems to get good remarks. It also has an impedance matching device which I do not have now.

Getting the antenna out of the attic HAS to help, don't you think? Not sure how far away from the eaves I will be able to work it (HOA). Also, from what I can tell orienting the antenna wire N - S seems preferred over E- W...is that what others have experienced? I live in Arizona.

It's a little hard to quantify how you would 'point' the PAR, since it's so broadbanded, and the directivity will vary with the frequency and how high you can get the antenna

Yes, getting the antenna out of the attic - if you can - is the way to go. The further away from the home, the better. However, with the HOA, you may need to be a bit more creative as to where you mount it. You haven't told us about your outdoor area...any big trees etc.? Mike

 

[cbadie]

I do not have any trees nearby. Best I think I can do is to run it alongside the eaves of the house, in a sloper configuration, maybe an inverted V depending on how I can rig it.

 

[majoco]

Why waste your money on a PAR EF-SWL when you can homebrew one of your own. It's only a bit of wire and a transformer to match the coax to your receiver.

9:1 Magnetic Longwire Balun / Unun – M0UKD – Amateur Radio Blog

 

[ka3jjz]

While I tend to agree that homebrewing is fun - and you learn something to boot - the Unun shown in your link is not using a binocular core - which the PAR does.

I would grant that it's a similar idea, but it's not the same thing...Mike

 

[Boombox]

Hi, I am going to try and move my HF antenna from inside the attic to outside. I could string it under the eaves which would make for a good length. Question is whether the longwire could have some bends in it to run the full length of the house? My back facing part of the house is not in a straight line.

Thank you

I wouldn't worry about bends. Single wire antennas don't become directional at SW frequencies until you're a wavelength or so, which would be approximately 100 ft at 9.5 mhz.

At that length (about 100 ft.), with a straight wire at that frequency (about 9.5 mhz), you'd get a cloverleaf. So, as you can tell, worrying about directionality is only something you want to do when you're designing an antenna for a specific range of frequencies, trying to get a signal from a specific direction. You're going to get nodes and lobes and all that, depending on how high or how low you tune.

But for most receiving situations -- you're not going to know, and you won't hear it. *Propagation* will affect what you hear more than whether your wire antenna has a bend in it.

 

[cbadie]

Thanks Boombox. I measured the side of my house and can run a wire N-S up and down a peak, about 50' without getting into any metal gutters. The coax run to the radio will be about 15', as well as a ground wire from the balun....although part of that may run alongside the gutter (but it's a coax). I think that should work.

 

[cbadie]

Thanks all for the feedback. I installed the PAR antenna but want to try a few other locations.
What I did was to run the antenna on the roof but held in place under the tiles (slipping the wire underneath), running up the peak and back (see attached). I'm concerned that this tile and the roof material underneath will impact the performance. Also it may become more prone to performance when wet and in storms, but I know there are protections against it. The antenna connects to the 9:1 at the near corner, and both the antenna side as well as the receiver side are grounded.

I have an antenna tuner as well which I could use, but have not considered that yet.

I was not able to get the antenna under the eaves along that same peak - too high and difficult to reach. Not sure I want to go back into the attic but that is still an option.

However, another option I am considering is to run the antenna along the eaves going in the opposite direction, so from left to right in the picture. It would be at about 10 - 12 ft height but it would run alongside the gutter, which I am not sure is any better. In this case I could use standoffs to get the antenna at least a few inches away from that. Any and all thoughts would be greatly appreciated.


CC&Rs - gotta love it - but I am also learning quite a bit about simple antenna installations.

 

[cbadie]

a picture would help

 

[prcguy]

If the gutter is metal and long, like 30 to 60ft you could replace the first downspout section with a plastic one to insulate it, then use the PAR transformer and use the rain gutter as an antenna. You would also want to pop rivet the sections together and make sure they are electrically connected.

Otherwise don't run an antenna wire close to or parallel with a rain gutter unless the gutter is a fraction the length of the antenna wire.
prcguy

Thanks all for the feedback. I installed the PAR antenna but want to try a few other locations.
What I did was to run the antenna on the roof but held in place under the tiles (slipping the wire underneath), running up the peak and back (see attached). I'm concerned that this tile and the roof material underneath will impact the performance. Also it may become more prone to performance when wet and in storms, but I know there are protections against it. The antenna connects to the 9:1 at the near corner, and both the antenna side as well as the receiver side are grounded.

I have an antenna tuner as well which I could use, but have not considered that yet.

I was not able to get the antenna under the eaves along that same peak - too high and difficult to reach. Not sure I want to go back into the attic but that is still an option.

However, another option I am considering is to run the antenna along the eaves going in the opposite direction, so from left to right in the picture. It would be at about 10 - 12 ft height but it would run alongside the gutter, which I am not sure is any better. In this case I could use standoffs to get the antenna at least a few inches away from that. Any and all thoughts would be greatly appreciated.


CC&Rs - gotta love it - but I am also learning quite a bit about simple antenna installations.

 

[Boombox]

I had a 60 ft. wire antenna within 6-8 inches of an aluminum gutter and had no problem with reception. I used zip wire, stapled to the overhang behind the gutters. Heard the world with that antenna. But that was just a cheap zip wire antenna, no balun or anything.

 

[cbadie]

Thanks to both of you, and not too surprising that there are different experiences. I may try it and try to keep it as far under the eaves as I can, now that I have a 'reference' from the rooftop. Cant hurt to experiment. Under the eaves will have the added benefit of keeping the wire protected from the sun.

I have an MFJ-16010 L-network random wire tuner, so not sure if that would help with any possible issues?

 

[ridgescan]

Take time one day and experiment with your equipment and space. Every one QTH has unique possibilities. The tuner just might help like prcguy stated above. Ya never know till you try.

 

[Fast1eddie]

Hi guys, thought I would throw my recent experiences in with the PAR and several different QTH's as I am divorced now and have moved around some. I've got the Par installed inside my apartment and run in a L configuration. My building is wooded and I am in the suburbs. I installed the 16010 tuner inline to a Icom R71A. I found the tuning to to be very sharp and with multiple noise peaks as tuning. Trick is to identify the one which is a tad louder than the rest and you are golden. Not going to try to articulate AC and RF theory; prcguy can explain in terms we all can comprehend.

My end conclusion is it does enhance performance but not by much, If you're into dial twiddling, go for it. I ended up removing it after several months of use and dx has not suffered.