how can i in-hanse my long wire performance

[fpeconsultant]

Chris - I notice that your profile says you use a 670' horizontal loop.  Do you have & would you be willing to share a schematic?  How is it terminated (if it is....) and what type of feedline do you use?  How high is it mounted?  I have the room and currently use a 300' LW - works well but I'm always looking to improve!

[ChrisSmolinski]

Chris - I notice that your profile says you use a 670' horizontal loop.  Do you have & would you be willing to share a schematic?  How is it terminated (if it is....) and what type of feedline do you use?  How high is it mounted?  I have the room and currently use a 300' LW - works well but I'm always looking to improve!

I have a short article about it here: http://www.hfunderpants.com/?p=1097

There's no termination, I just feed it with 100 ft of RG-6 into a 12:1 balun (which may not be the ideal ratio). The height varies but is around 25 to 50 ft, depending on what trees I could make use of.

It is by far the best antenna I have had in 35 years of DXing.

[rwfisher]

I wrote up another blog post about sky loop antennas, this time with an emphasis on construction tips: http://www.hfunderpants.com/?p=1097

Perhaps a naive question...would a 58 meter perimeter loop (stretched along the edge of a roof) have any utility?

[ChrisSmolinski]

Perhaps a naive question...would a 58 meter perimeter loop (stretched along the edge of a roof) have any utility?

You mean where the gutters are (or would be if you don't have any)?  

If you've already got the wire and it's easy to install it, it might be worth a try. My main concern is that you're putting the antenna around (and close to) your house - a major source of potential QRM.

I suspect it would be better than an indoor antenna, though.

[rdla4]

As Chris says, it may be worth a try to sting it around your house. But if your house is like my house, Its a noisy RF Killing zone. I try to keep my antennas more that 30 ft from the house to keep away from the "zone of radio death." Even then, I still have trouble from my neighbor's Super Trashmaster 500kW atom smasher....or the plasma TV he has. I am guessing its an atom smasher however.
If thats you only choice, its better than nuttin. 
If you have any space some sort of "loop", pendant, or other 'closed loop' system fed with a balun you will experience much quieter reception. (The antenna wire comes from one side of the balun, and then returns on the other side of the balun. I am using a cheap Cable TV coax to twinlead balun. It probably is nowhere near perfect, but it is remarkably quieter vs a longwire.

[rwfisher]

Not sure it counts as a long wire...but if I wrap 600+ feet of wire around a 12x12 room, any chance of improving signal/noise?  Or would I be better off wrapping the equivalent around the house?  OR....heh heh hehhhhhh...burying it around the perimeter of my property.....


I'm also curious....how does one pick a balun when looking for broadband HF performance?  

[rwfisher]

As Chris says, it may be worth a try to sting it around your house. But if your house is like my house, Its a noisy RF Killing zone. I try to keep my antennas more that 30 ft from the house to keep away from the "zone of radio death." Even then, I still have trouble from my neighbor's Super Trashmaster 500kW atom smasher....or the plasma TV he has. I am guessing its an atom smasher however.
If thats you only choice, its better than nuttin. 
If you have any space some sort of "loop", pendant, or other 'closed loop' system fed with a balun you will experience much quieter reception. (The antenna wire comes from one side of the balun, and then returns on the other side of the balun. I am using a cheap Cable TV coax to twinlead balun. It probably is nowhere near perfect, but it is remarkably quieter vs a longwire.

You should try and get a blood sample from your neighbor after the next superbowl and see if he has elevated 24Na levels from his personal LHC.....

[Pigmeat]

I used to be interested in tropical band dx,so I put a dipole for the 90 meter band around the eaves of the roof,as you mentioned. As I put it up in early winter,it worked like gangbusters. Come March,when the thunderstorm season started kicking up in the region,the antenna became a giant noise collector. It stayed that way until November,when it reverted to being a great antenna.

Loops are generally quieter than dipoles,give it a try,you've got nothing to lose.

I once wrapped 150 ft. around a 12x12 foot room. Crap results. I did better stringing 30 feet of wire out the window to a tall bush.

[ChrisSmolinski]

Loops are generally quieter than dipoles,give it a try,you've got nothing to lose.

This is something that has become very apparent to me over the last few years. For a given size antenna, a loop provides a much better signal to noise ratio than a dipole. I really can't stress this enough to anyone in the hobby. If you have a dipole now, make putting up a loop antenna your next project. You will almost certainly be impressed with the results.

I once wrapped 150 ft. around a 12x12 foot room. Crap results. I did better stringing 30 feet of wire out the window to a tall bush.

Yep, getting an antenna outside has at least two benefits - you get further away from RFI producers (TVs, computers, etc) and you get stronger signals, since RF tends to get attenuated by the structure.

If you're "not allowed" to have an antenna, be creative. If you have a fenced in yard, run the antenna wire along the top of the fence (that plus the house should let you make a loop). Disguise your antenna, make it appear to be something else.

[Pigmeat]

In the days of the uber-dipole,I found I could use the chain link fence around the backyard as a low noise antenna. I clamped the center conductor of my coax to the fence and let the braid float.

I still use the fence-tenna when the noise levels get ridiculous. It does well as a general receiving antenna down to about 1400 khz,give or take.

[rwfisher]

Soldered 40 ft of 22GA wire to the center connector of 30 ft of coax and ran it out the window and down the deck bannister.  It's a bit of overkill...lots of intermod, etc but the attenuate function on the PCR1000 gets it down to something reasonable.  Here's a scan from 6MHz to ~14MHz this evening starting at around 0010 UTC or so...

[Lex]

I also tried various popular indoor wire-around-the-room loops.  None of 'em fared any better than a hank of random wire strung along the ceiling.

The only homebrewed indoor loop that's been consistently better for me is a shielded coaxial cable loop based on a design from Joe Carr's 1990s receiving antenna handbook.  It's pretty similar to the popular KR1ST loop, just using coax instead of copper tubing.  I hang it near a window and twiddle the orientation just enough to null out the worst local RFI.  It's directional on MW but not HF, although the directional characteristic does help null out some household RFI.

Sometimes I'll sneak 30' or so of magnet wire out a window and up a nearby tree, but usually one my apartment building's maintenance guys will spot it and tear it down.  No great loss since magnet wire is cheap.  I'm more concerned about safety - don't want anyone to get snagged on it while they're up a ladder doing their jobs.

I don't have access to a proper ground so I just use odd lengths of magnet wire as makeshift counterpoises.  It works pretty well on some frequencies, not at all on others.  I just experiment with the lengths until I get it right for the 6800-7000 kHz range.

[ChrisSmolinski]

The PA0RDT mini-whip (google for more info) gets a lot of good reviews. The webSDR in .nl uses one, and gets pretty good reception. AFAIK there is no commercial version, but it doesn't have a huge number of components. 

The key, as always, is to get the antenna outside. The difference between an indoor and outdoor antenna is huge. The mini whip is pretty small, I'd imagine that most folks could easily disguise one.

[BoomboxDX]

i have a 200' long wire and was wondering what i could do to get better performance from my receiver's. i'm using a RS dx394,RS dx302 and a icom R71a

200 ft. is a fair chunk of wire, especially on shortwave, where an antenna that long can start to become directional (you can get a cloverleaf pattern when the length of the antenna is over a wavelength long).

Maybe re-orienting the antenna you already have would bring in more stations from the areas of the world you want to hear.

I've never tried a large loop but have read about them and there are people who swear by them.  That also sounds like a good idea.

[Beerus Maximus]

If you don't want to shell out the $$$ for an EZ Hang, just get your hands on a cheap slingshot and some 1 oz steel sinkers (please don't use lead). Get a big spool of 20lb-ish test monofilament fishing line, and some masonary line (from Home Depot).

Lay out a zig zag pattern of the fishing line on the ground in front of you. Estimate about what you would need to get it over the tree in question, but don't cut it from the spool, just let the spool lie there on the ground too. But the zig zag pattern on the ground is important, so that it easily (and with minimal friction) flies up into the air. Tie a sinker to the end of the fishing line.

Hold the slingshot with a gloved hand (the hand you use to pull the sling back can be bare) and, wearing goggles, fire that sinker up to were you want the line to go. It almost always pays off to aim higher than where you really want it. With some practice this works well. Next, use the fishing line that has been launched over the tree to pull the masonary line up over the tree. Masonary line is much stronger than the fishing line you just used, and is also "slippery" and doesn't knot. Finally, use the masonary line to pull your antenna rope over the tree, which really should be the good UV resistant dacron type stuff they sell on eBay or at Ham Radio Outlet. Rope from Home Depot will not work well at all for antennas. Use real antenna rope, it's worth the money.

The slingshot, fishing line, sinkers and masonary line is probably a $40 initial investment. Good antenna rope is not all that expensive either; I've found the Davis RF stuff on eBay to be excellent and I believe this is also the stuff that Ham Radio Outlet stocks. It lasts forever, doesn't kink, and is really is easy to work with.