Antenna Assistance

[KE4IZA]

To being with I am apartment bound which means the owner has forbid me to erect anykind of outside antenna and moving at this time is not an option. So ..... I have made a dipole inside. I live on the bottom floor of a 2 story wood frame building. My dipole is in the apartment center, 6" from the ceiling, across the livingroom and down the hallway in a straight line. The dipole is made from 2 metal slinky coils with a Centaur 1:1 balun in the middle. The antenna is almost 25' long. I do get out but not real well. Most of the time I can hear stations but in the background. This maybe because of band conditions, I do not know. I have been told to remove the slinky coils and replace them with a wire and to make the dipole 66' long following the apartment contour if need be and this would work better as the slinky coils are nothing more than inductors and almost worthless

[WB2WIK]

Can you park your car or truck (assuming you have one) close enough to the apartment that you could sneak a small piece of coax from inside the apartment out to the vehicle?  If so, you could use any number of highly effective mobile HF antennas *outside* without actually having an antenna installed outside -- it would be on your vehicle, and they have to permit that.

That's an old trick I've used many times.  A good HF whip on the car will run circles around most "indoor" HF antennas.

WB2WIK/6

[KB6NU]

I'm not so sure that running 66' of wire in haphazard fashion will work much better than your Slinky antenna. Indoor antennas are always compromise antennas.

I've been using a Slinky antenna for a month now on 30m, and doing quite well with it. If I can hear 'em, I can work 'em, and that includes DX stations.

You might try checking to make sure that all connections are well soldered. If they are, you might try the antenna without the balun. Also, is there any kind of attic space? If so, you might see if you can put it up there.

Good luck & 73!

Dan KB6NU

Many years ago I tried a slinky antenna in an attic.  It was about 25 to 30 feet extended.  I used it for awhile but it didn't seem to get out.  I replaced the slinky with heavy wire (#8) and fed it with an antenna tuner.  The difference was unbelievable.  The slinky performed poorly.

[N6AJR]

I agree.. save the bucks, dump the slinkies, use a piece of coax, the longest dipole you can fit in the attic, or where ever and run through a tuner to work all the bands.. cheep effective and hidden

[K8AG]

Rather than running coax, the smallest of which is not even close to being invisable, here are a couple of tips which worked for me:

1) throw a very thin wire up into a tree and use a tuner.  Get the wire up off the ground (8 feet or more) in case the lawn mowers walk by.  Thin wire can be quite invisible.  If it gets broken, simple replace it.  Perhaps run a counterpoise around the room if a really good rf ground isn't available (i.e. cold water pipe assuming copper plumbing).

2) Even a wooden apartment will have gutters.  If the gutters are alumimum or (fancy) brass, you may be able to load the gutters up with, again, an antenna tuner.  I have gotten out quite well this way.

FWIW

73

John Pawlicki, K8AG

[ON4MGY]

Buy or borrow the ARRL book "Stealth amateur radio" by NT0Z.
In this book you'll find a lot of information on building and using invisible antennas. I really learned a lot from this book and I can give you an idea how to operate in your situation.

Best 73 de ON4MGY Nic

[KC8VWM]

Some Antenna Ideas

While I have heard about the slinky idea for HF, why not take a look at some of these other ideas.

Since most people are allowed to put up a satellite dish, why not make this work to your advantage?

IDEA #1

For VHF and UHF (and possibly 6 meters) operation you can buy one of those outdoor TV antennas that resemble a horizontal dipole that mount directly over the curve of the satellite dish. I suppose that it could be trimmed to resonate frequency too. Would probably be very easy to trim one for 6 meters.

While you don't have to actually buy the "clip on TV antenna for a satellite dish" You can make your own that closely resembles it for your particular band.

Here's a picture of the sattelite antenna idea for VHF/UHF and possibly 6 meters:

http://www.doubleberger.com/TV%2DVCR%2DAccessories/IDC15088/TERK%2DTV42.htm

IDEA #2 (VHF/UHF)

PVC vents on roofs are also an excellent way to make a multiband 1/4 wave antennas. "White" lamp cord that resembles the color of the PVC works best.

How about putting up a fake "vent"?
Hardware stores usually sell these vents pretty cheap. Cut to approx. 19.5" and your vent will make an excellent radiator on 2 meters.

The vent should be located as high a possible, for adequate ventilation of course.

I was thinking about a 6 meter beam in the attic, but it might be easier to construct a 6m horizontal beam out of wire that closely resembles the color of the roof shingles.

IDEA # 3 (HF Stealth Mode)

You can string up a nice long wire dipole by tucking it under that plastic PVC siding used on most of these newer homes.

My favorite antenna stealth trick is to purposely install what may appear to be cable TV wire along the side of your house or building. Make it appear professionally installed by the cable guy himself!

Be sure it looks like it runs from one destination to another. Construct the wire using official "cable guy" tie downs and the whole nine yards.

Be sure it bends around window frames, doorways, and try to make it as long as possible for HF. Heck, you could even put one of those yellow colored "utility tags" on your new long wire to show everyone one in your neighborhood that your newly installed HF antenna was even certified, dated, and initialed by the cable company.

If you think the newly added wire might raise suspicions, you could simply say something like, "Yeah, got tired of that slow dial up internet access. They had a great deal on cable internet access. they installed that extra cable for my new broadband cable modem. I will never go back to dial up again!"


Charles Bushell

KC8VWM