Long Wire Transformer / DIY Antenna

[andrewccm]

To keep from further hijacking a previous thread, I thought I'd go ahead and start a new one...

What started off as an exercise in futility trying to get my Eton E1XM to receive anything more than static has evolved into a fun little project for me.

A little background, I have many scanners, PC's, wireless router and bridges throughout my home. Upon adding this radio, I quickly discovered that I was getting all kinds of noise. So I ran wire to the attic and got a "little" better reception but still lots of static.

I then added a Sony AN-LP1 active loop. That helped a little bit, but not enough to really make me happy with my endeavor into SW radio. Finally after trying everywhere in my house upstairs and down, I took my E1 out in the backyard with the AN-LP1... WOW WHAT A DIFFERENCE. Ultimately, I chalked it up to pretty much tons of RF in my home (scary).

I then decide to try several cheapie projects to get my antenna outside without HOA freaking out. I ended up just running some speaker wire out my upstairs window and strung it through the trees. While this worked pretty well, I was still getting quite a lot of noise (albeit, able to pick up lots of stuff that I previously was unable to).

I decided that I needed to shield the wire going out of my house prior to the speaker wire. So...I grab an old mag mount CB antenna and cut off the cable. I run this cable into a PAL to P259 12" adapter which goes into the external antenna port on my E1XM. The other side of the cable I just splice into the speaker wire outside my window. Well...this worked, but still pretty noisy...

I then add a ground to the mag wire which seemed to slightly help... Figuring that the old mag cable wasn't very shielded, I opt'd to replace it with RG6. I ran that into a P259 to BNC connector at one end and spliced the other into a ground inside and to the speaker wire outside. This seems to be working pretty well and it mates up with my E1XM fairly nice.

However, I would think I could do better with the noise by properly grounding and using a better ohm matching transformer rather than bare wire to coax. I have been looking into this unit ICE 180A which was highly recommended via THIS ARTICLE.

Does anyone have any experience with this product? Also, I do plan to possibly construct something a bit better than a bunch of copper speaker wire strung in a tree. But I do have to keep it on the down low due to HOA.

I like the idea of tinkering a lot.

Couple of silly questions:

1. Has anyone tried using a heavy duty long tape measure as a retractable antenna?

2. Has anyone tried using the metal fleiching around their roofline as a large loop?

I know some of this sounds silly... But I am just playing around and learning as I go along. I have come a long way in 2 short months of scanning and now SW.

Thanks for any comments or suggestions you may have.

 

[k9rzz]

You can try anything metal for an antenna. The hot new HF beams for hams, the STEPPIR antennas are (I guess) copper tape inside plastic tubing that's adjusted in length by stepper motors, so by all means try a metal tape measure! Rain gutters, flag poles, cattle fence ... whatever ... give it a try.

 

[Shortwavewave]

Ive heard of quite a few using tape measures
Sounds to me like you want to get rid of all the noise....Not to sound mean, but THIS AINT GONNA Happen, unless you always go outside, or turn off EVERYTHING in your house.

Ill tell you whats worked for me though, one thing to remember though in somthing thing like this hobby, facts shmacks IF IT WORKS FOR YOU THEN IT WORKS

1. GETS A BALUN/ or transformer(some call it) it works and works WELL.

2. Dont worry about a ground if your just using a longwire(for me it does nothing, and Ive stayed up days testing this out)

3. USE a good Coax, I use 75ohm Quad sheild, but other stuff is out there that works better.

4. If you hook your RX to computer sound(input) use a RF Choke(also sometimes called transformers)

5. Try to use a battery(s) as much as possible.

6. SOLDER, SOLDER, and oh yeah SOLDER!
(ive kicked my butt for not doing this went a whole day thinking my radio burnt up because I forgot to solder)

 

[ka3jjz]

Andrew, you're on the right track. Get the antenna outside as far as you can, and many recommend the use of a magnetic longwire balun as well.

Lots of things - such as gutters and rainspouts - can be set up as an antenna. Experimentation is key. If it were me, and I could get on the roof, a wire loop, strung around its perimeter, probably fed with a balun and using coax colored white (I see it constantly being used by cable TV installers) would be one of my first choices. Loops are less sensitive to certain kinds of noise, and a balun might cut the noise even more. Keeping the wire low on the roof - using thin insulated wire would make it virtually invisible, as should the use of white colored coax (black coax coming down a light colored surface is rather like a zebra in a open field...).

73 Mike

 

[andrewccm]

Thanks for the suggestions.

Have any of you used that transformer I mentioned? Looks like it's specifically made for single wire HF applications.

 

[ka3jjz]

As the loop is closed, you would simply tie both ends of the loop to the balun.
for example (yes the artwork sucks- I can solder, but I can't draw worth a dxxx)

--------------------------------
| |
| |
| |
| |
-----------balun--------------|

Despite it's name, a loop need not be circular; it can be any shape, though most tec refs will tell you to keep it symmetrical. For receiving apps, it's likely to be somewhat more forgiving.

[edit] I KNEW the bloody thing wouldn't show correctly - the 2nd line of vertical bars should appear at the very end of the straight line, forming a box - which is one of many possible shapes for a loop

I would, of course, wait until an early morning to do the stringing. Don't want to get baked up there!

73 Mike

 

[prcguy]

It looks like the transformer in your link is for beverage antennas which are usually several hundred feet long and a few feet off the ground. They are directional and not very common due to the space requirements. There are transformers sold for end fed wires and some people report good results but I'm not a believer in multi band end fed wires except for ones cut specifically for 1/2 wavelength for one frequency. At lengths other than 1/2 (or exact multiples) the antenna wants another conductor for current to flow and that becomes the coax.
prcguy

Thanks for the suggestions.

Have any of you used that transformer I mentioned? Looks like it's specifically made for single wire HF applications.

 

[Shortwavewave]

This is How I have my Balun, and Loop setup Works Perfect for ME

 

[andrewccm]

Thanks for the replies. I truly appreciate it.

I changed up my wire today into an L. My results tonight have been surprisingly good. Pretty much low noise and picking up a lot more than normal. This is pretty fun stuff.

I am thinking I will modify and/or try a loop next. What type of balun do you guys use (where to get it)?

I am headed down to the Texas coast for a week Sunday. Kinda wondering if taking my E1 and AN-LP1 might be worthwhile. I am taking my BCD396T for sure.

Thanks again everyone.

 

[Shortwavewave]

I am thinking I will modify and/or try a loop next. What type of balun do you guys use (where to get it)?

Well Universal Radios Sells some pre-made baluns
http://www.universal-radio.com/catalog/antsup.html

IF you want to build your own, Ive Ordered from here once before https://www.amidoncorp.com/
43, 75, and F types have all worked great for me.

You can join Shortwave-SWL-Antenna Yahoo Group for all kinds of information.

And Yes take your radio with you to the coast, you will hear ALOT, you can also try even getting a digital voice recorder and record what you hear.

Enjoy!