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Remote Tuned Slinky Dipole for Restricted Hams

Created by James Zappulla, N1FDX on 2021-02-10

"Editor's Note: Due to the popularity of some of eHam's older articles, many of which you may not have read, the eHam.net team has decided to rerun some of the best articles that we have received since eHam's inception. These articles will be reprinted to add to the quality of eHam's content and in a show of appreciation to the authors of these articles." This article was originally published on: 01/30/2010

Remote Tuned Slinky Dipole for Restricted Hams

Here's an idea for hams that have antenna restrictions or maybe just want an indoor backup antenna system. I've played with the Slinky toys in many different antenna configurations and have had good results. I always take a few with my FT-817 and a tuner on vacation.

I've had 2 in my attic for many years as a backup and they work real well on 40 thru 10 meters with the autotuner in my IC-756ProIII and 75 meters with the MFJ-949E manual tuner. The Slinkys are stretched out to about 18 ft per side with a guide string running down the middle for support, about 25 ft above ground in the attic.

I thought this time I would take the Slinky to the next step. I remotely mounted a LDG Z-100 autotuner in the attic at the antenna. I directly coupled the tuner to a W2DU 1-to-1 balun with a dual male adapter then fed the Slinky. I use alligator clips bound with wire ties around them to connect to the Slinky.

The Z-100 model I purchased came setup to work with most Icom radios that have the remote antenna control connector on the rear of the transceiver. (many models available) I lengthened the control cable to reach the attic by creating an extension to the Molex connector that would normally connect to the rear of the transceiver and connected it to my IC-706 for the on-air test.

I first tried to see on what bands it would tune and it seemed to have no problem on 80 thru 6 meters and even 160. Over the next few days I made numerous contacts from E.MA. throughout the U.S. as far as the west coast and into Europe on 20 and 40 meters. A few more local on 75 meters. I'm was pretty happy with that performance.

My intention for writing this article is to share an antenna idea with fellow hams especially with antenna restrictions etc. It's an idea I tried and had good results with, use your imagination and add you own spin. I've used the Slinky in many different configurations, horizontal dipole, vertical dipole and extended to as little as 5 ft per side. Give them a try.

 

73, See you on the bands!
Jay, N1FDX

 

KBKZ21052021-03-01
Remote Tuned Slinky Dipole for Restricted Hams
yreryer
VK2MS2021-02-22
Re: Remote Tuned Slinky Dipole for Restricted Hams
That 'thing'is the worst posible buy as an antenna as far as I am concerned. Mine sprang itself into a mess and hours of work could not get it sorted....best place for it?....leave it where it is now. Horrible thing...
Reply to a comment by : WB0FDJ on 2021-02-13

When I moved into my current home it was getting on winter without any chance of getting up a decent outdoor antenna. As an experiment I put up a slinky dipole overhead in the upstairs shack where it still sits some 13+ years later. I made a few contacts on HF with it and would judge it as "OK". But a few years ago I found an opening on 6 meters while listening to my FT-817 and, using a tuner, quickly made several good CW and SSB QSO's. For the cost it's worth experimenting with. Back in the day I knew a ham who used this and a HW-16 to make a lot of contacts from his apartment.
WB0FDJ2021-02-13
Remote Tuned Slinky Dipole for Restricted Hams
When I moved into my current home it was getting on winter without any chance of getting up a decent outdoor antenna. As an experiment I put up a slinky dipole overhead in the upstairs shack where it still sits some 13+ years later. I made a few contacts on HF with it and would judge it as "OK". But a few years ago I found an opening on 6 meters while listening to my FT-817 and, using a tuner, quickly made several good CW and SSB QSO's. For the cost it's worth experimenting with. Back in the day I knew a ham who used this and a HW-16 to make a lot of contacts from his apartment.
W4FID2021-02-10
Remote Tuned Slinky Dipole for Restricted Hams
I did something similar and had useable results. I put a 40M diploe in my attic. About 6" under the ridge pole. Each "leg" was about 25 feet horizontal and 15 feet sloping down at 45* along the roof line. The center wire was running due east/west. About 14 feet above ground and in proximity to house wiring, AC ducts, etc. The bend of one leg was running due south with the end about 8 feet above ground. The bend on the other leg was running due north with the end about 8 feet above ground. So the wire was "Z" shaped. The entire wire was in the attic -- nothing outside -- and long enough insulators to avoid any chance of arcing to the wood house construction. At the center of the dipole instead of an insulator I used an SGC 237 coupler. In really generic terms the coupler "thought" one wire was an antenna and the other one was a counterpoise. There was about 25 feet of coax between the rig and the coupler. No balun or choke. I ran 100 watts and relied completely on the coupler not a tuner at the rig or the one built into the rig. When 20 and 15 were open I worked some DX. On 40 I could always work someone. Mostly SSB -- maybe 3/4 of the time -- and the rest CW. This was pre FT8 times. Likely FT8 would have done much better for me. 80M set off the telephone and doorbell. 10 was never open. But 40-30-20-15 did OK. This was during the low sun cycle from north central FL. Not a beach or mountain location that favors radio or a DX call that draws attention. It was 100% invisible so the HOA had no knowledge let along complaints. Never thought about using a slinky but likely would be as good or better.