Building a shortwave antenna

[CapnRefsmmat]

I've noticed recently how much improved my shortwave reception is with the 15-foot wire antenna that came with my radio (although I still don't pick up much), so I figured it would be a good idea to build a longer antenna of some sort.

I did a bit of research on the wiki and such, and came up with this page. Unfortunately, it wants a 144-foot-long antenna - and the longest practical (straight) antenna I could have is 40 feet or so (outdoors, running on the roof). Is there some way I could use the 40 feet available to make the equivalent of a 144-foot antenna, or will I have to stick with hearing only the higher bands?

 

[K9GTJ]

I know there are many skilled here that will give you lots of technical detail but I can say as a kid 30+ years ago I had all kind of long wire or slinky style antennas for SW listening. It seem SW listening is generally very forgiving in antenna design and length.

I had one that was a zig-zag pattern on the roof. It went back and forth between insulators and worked pretty well.

You could make a loop on you roof that would likely get you your length.

 

[CapnRefsmmat]

Would I ideally have several of different lengths (as in the link I provided above) to pick up multiple bands?

 

[gcgrotz]

Depending on the radio, 144ft may be too much. It will overload most portables.

RadioShack has a kit for SWL that works pretty good, it has 75ft of wire but you just put up as much as you can.

You should be able to pick up a lot with just 15ft but it depends... if it is in the house you may be buried in electrical noises. It also depends on what freqs you are trying and at what time of day. Research the wiki and find out about shortwave propagation. With the sunspots being low, the higher freqs (above 15 Mhz or so) may be dead 24hours a day. And the low freqs will be dead during the day so that doesn't leave you with much.

Above all, it takes patience and knowing when/where to listen.

 

[CapnRefsmmat]

Depending on the radio, 144ft may be too much. It will overload most portables.

I thought so. I'm going to go for about 40 feet. Think that might work?

RadioShack has a kit for SWL that works pretty good, it has 75ft of wire but you just put up as much as you can.

Have a link? I can't find it on their website.

 

[KC4ZEX]

The Radio Shack part no. is 278-758 . I would use from 30 to 40 ft. no more. Most new portables can't stand anymore without overloading. You should get good results across the band.

 

[gcgrotz]

I had about 60 feet attached to my R75 before I moved last year. It worked very well. Radio New Zealand was very reliable most mornings on 9890. Could hear most traffic on 5616 aero freq including Shanwick when static wasn't too high. 40 feet ought to work great. I'm getting ready to buy the PAR endfed swl antenna and I think it is 45 feet. It gets great reviews and I think for my situation on this small city lot it is about the best I could do.

BTW, if anybody is interested, I used to have a Radio Works Carolina Windom 80 for ham use and that thing worked great on ham bands (20m really zinged!) and for swl also, even down into the AM broadcast band. They make a smaller version for swl use if you have about 65 feet to hang it up.