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[Articles Home]  [Add Article]  

The Slinky as an Antenna

Dick Reid (KK4OBI) on April 20, 2013
View comments about this article!

The Slinky as an Antenna


It is cheap. It's made of metal. It can stretched to 15 feet or more. Wouldn't that be good for an antenna if you stretched it to the right length? All you need is some rope, wood or plastic pipe to support it and some coax and bits out of the junk box. It seems perfect for a stealth antenna in the attic or in a room or even outside if you put on some protective coating.

Based on the many Slinky items on Google and YouTube, a lot of folks think like this and have had tried using it as an antenna.

The problem I have is that there is such a big difference in results people have reported. Some say it works...¦ kinda. Others rave about it, notably those with antenna tuners or selling antennas. On the overall, reports I have seen without tuners are pretty underwhelming. What is going on? Where is an explanation of how a Slinky works? Why isn't it usable for most folks? If possible, how to make it resonate where you want?

The Slinky Dipole

First experiment. Let's try two Slinkys as a half-wave dipole about 18 feet long about shoulder height for convenience. This length should resonate around the 11-meter or 6-meter bands, right? Again, kinda.

The first thing I found is that the spacing between each quarter-wave needs to be close, one inch or less which gives four resonant points of around 10, 25, 40 and 50 MHz. Spacing of 8-9 inches gives only three points around 22, 33 and 52 MHz.

And of course, common current on a 50 ohm unbalanced coax feed gives varying results in SWR/Impedance, peak positions and doublet formation. With junk box parts, I solved that with a 1:1 choke balun of 13 turns of RG58/U on a 3 inch diameter form. This stops common current from 9 to 45 MHz and helps some on either side.

Second Experiment. Lets see what changing the length of the dipole does to frequency. We should be able to tune it by changing the length, right? Not really.

Dipole

Peak 1

SWR

Peak 2

SWR

Peak 3

SWR

Peak 4

SWR

20 ft

8.5

mhz

1.3

z=55

25.0

mhz

1.0

z=50

40.0

mhz

1.1

z=55

53.5

mhz

1.1

z=50

16 ft

9.3

mhz

1.4

z=64

26.1

mhz

1.1

z=56

40.2

mhz

1.2

z=56

53.3

mhz

1.1

z=55

12 ft

9.6

mhz

1.4

z=68

26.5

mhz

1.0

z=50

40.9

mhz

1.1

z=50

53.8

mhz

1.0

z=50

8 ft

9.7

mhz

1.3

z=60

26.0

mhz

1.2

z=50

39.5

mhz

1.5

z=68

50.8

mhz

1.0

z=42

All this stretching produces a change of maybe 1 MHz. Big whoop. Results: You can not tune to 80, 40, 30, 20, 18, 15, 12 or 10 meters with a Slinky. The only possibility is 6 meters at 50-54 MHz. This explains why most hams give up on using Slinkys for antennas or force-feed this non-resonant radiator with an antenna tuner.

Lets face it, Slinkys are coils not wires. Each is an air wound coil of 98 turns at about 70mm diameter. Length here is more a matter of inductance, in this case each Slinky runs about 15 microHenrys (uH) at 10 feet to 37 uH at 4 feet. We will use that range as a working guideline.

Looking further I see Slinkys used as quarter-wave monopoles or helical antennas. The difference is the need of ground plane/counterpoise and that shorting out turns can do the tuning.

I tried that approach. Sure enough one Slinky has about the same four resonant frequencies as two Slinkies in a dipole. However, using a clip to short out turns was not good. It looks like the shorting wire and possibly the shorted section were radiating to cause new peaks, distorted peaks and doublets.

What does work is to compress the unused turns into a solid cylinder and load that. Only the desired number of turns are then free to radiate. Smaller increments in inductance are possible.

Third Experiment. At fixed horizontal length of 10 feet, lets see what changing the number of turns does to inductance and resonant frequencies. Interesting results.

Turns

Peak 1

SWR

Peak 2

SWR

Peak 3

SWR

Peak 4

SWR

98

15.1 uH

8.2

mhz

1.3

z=64

23.6

mhz

1.4

z=62

37.3

mhz

1.1

z=55

50.1

mhz

1.5

z=32

88

12.1 uH

8.8

mhz

1.5

z=66

25.6

mhz

1.0

z=47

40.6

mhz

1.3

z=62

55.3

mhz

2.5

z=23

78

9.5 uH

9.5

mhz

1.4

z=68

27.7

mhz

1.0

z=49

44.0

mhz

1.4

z=62

~60

mhz

>3

>130

68

7.2 uH

10.4

mhz

1.5

z=73

30.5

mhz

1.1

z=50

48-49

mhz

1.7-1.9

z=34-39

None


58

5.2 uH

11.6

mhz

1.5

z=71

34.4

mhz

1.0

z=47

56-57

mhz

2.3

z=46

None


OK, we now can tune to 30 meters, 12 meters, 11 meters (CB), 10 meters and 6 meters. Still 80, 60, 40, 20, 17 and 15 meters are out of reach. We need more turns to get a greater range of inductance to diddle with.

Fourth Experiment. Let's see what changing the number of turns does after adding a second Slinky and stretching both into a horizontal monopole 16 feet long.

Turns

Peak 1

Peak 2

Peak 3

Peak 4

Peak 5

Peak 6

Peak 7

195

37.4 uH

4.7 mhz

1.5 swr

13.6 mhz

1.9 swr

22.0 mhz

2.3 swr

29.5 mhz

1.4 swr

37.0 mhz

1.8 swr

43.9 mhz

2.0 swr

50.2 mhz

2.0 swr

175

30.1 uH

5.3 mhz

1.3 swr

14.4 mhz

1.7 swr

24.4 mhz

1.8 swr

32.4 mhz

1.3 swr

41.1 mhz

1.7 swr

47.3 mhz

1.7 swr

55.5 mhz

>3

155

23.6 uH

5.8 mhz

1.2 swr

16.3 mhz

1.9 swr

26.2 Mhz

1.4 swr

36.5 mhz

1.4 swr

44.8 mhz

1.6 swr

~53 mhz

2.8 swr

None

We get four additional peaks but none for 80 meters. A third Slinky would be required for that.

The good news is that we can tune to 60, 20, 15 and 12 meters and are closing in on 40 meters. What we need is some in-between inductance.

Fifth Experiment. Continuing from 155 turns above, let's reduce the length from 16 feet down to 10 feet. This will raise the resonant frequency towards 40 meters and bring the inductance back up so we can fine tune the turns needed.

Turns

Peak 1

Peak 2

Peak 3

Peak 4

Peak 5

Peak 6

Peak 7

155

37.8 uH

6.6 mhz

1.0 swr

18.1 mhz

1.8 swr

28.6 mhz

1.3 swr

38.5 mhz

1.7 swr

46.1 mhz

1.6 swr

>55 mhz

>3 swr

None

145

33.1 uH

7.0 mhz

1.0 swr

19.4 mhz

1.6 swr

30.0 mhz

1.1 swr

40.8 mhz

1.5 swr

48.5 mhz

1.6 swr

>57 mhz

>3 swr

None

140

30.8 uH

7.3 mhz

1.0 swr

20.3 mhz

1.5 swr

31.1 mhz

1.0 swr

41.7 mhz

1.5 swr

50.3-50.8

2.0 swr

None

None

135

28.7 uH

7.6mhz

1.0 swr

21.0mhz

1.5 swr

32.4mhz

1.0 swr

43.1mhz

1.5 swr

52.1-52.9

2.4 swr

None

None

Aha! Peak 1 nails the 40-meter band from 145 to 140 turns at a 1:1.0 SWR. It looks like Peak 3 will cover the 10-meter band in the range from 145 to around 160 turns. A word of caution: These data are taken near earth. Results will be different on an elevated antenna. If you try to duplicate this, do your own tuning.

Commentary

Ok, I now know the basic idea of how to get a Slinky(s) to tune to the HF bands. Turns out it is not so easy nor is a Slinky of much use as a multi-band antenna.

Efficiency is another consideration. The useless resonant points are dissipating part of the RF power into the air at frequencies that do no good. And of course, the 6 to 7-fold higher resistance of steel is dissipating some more your power as excess heat.

Another study by Martin Ehrenfried, G8JNJ, http://g8jnj.webs.com/Slinkies.pdf also notes about efficiency that the steel resistive losses are high, "3dB across just ten turns"¯. This suggests that the Springy may be radiating little or nothing towards the end of the coil.

In his study he uses a number of Springys, the 75-turn British version of the Slinky, with a 9 meter fiberglass pole, 4:1 balun and antenna tuner to load the rig. Most importantly, he compared the Springy antenna gain relative to his conventional vertical antenna as measured "about 2 miles away from the transmitter site"¯. At the ten frequencies measured all but one were "2 to 3 dB worse than a straight wire"¯. I add, two frequencies were worse than 5 dB down.

Conclusion

Other than Slinkys store in less space, I see no good reason to use them instead of wire.

And if you have an antenna tuner, all bets are off. Why mess with a Slinky? You can work the HF bands with a wire, say 25 to 40 feet long, in the rafters, under the eaves, draped over something or tossed up in a tree. Go for it! Hams even report making contacts with tuners by loading gutters, ladders, metal sheds, fences, even cars.

Dick Reid, KK4OBI 14 March 2013

dickreid1@aol.com

Member Comments:
This article has expired. No more comments may be added.
 
The Slinky as an Antenna  
by W7AIT on April 20, 2013 Mail this to a friend!
NO, NO, NO NO! NOT THIS IDIOT IDEA AGAIN! THIS IS AN OLD TRICK PULLED ON ALL NEWBIES.

ITS LIKE "GO GET ME A BUCKET OF PROP WASH" AT AN AIRPORT FOR NEWBIE MECHANICS.

THESE ANTENNAS DON'T WORK! LETS NOT GO THERE!

HOW DO I KNOW? I HAD SOME SPARE TIME AND WAS STUPID ENOUGH ONCE TO TRY IT.

THEY ARE:
1. SO MECHANICALLY UNSTABLE YOU CAN'T EVEN GET CLOSE TUNING, LOADING, ETC - TOTALLY UNSTABLE AND UNUSEABLE!
2. CAN'T SOLDER ANYTHING TO STEEL! CAN'T PRUNE STEEL EITHER!
3. BLOWING IN THE WIND - THESE ARE ALL OVER THE PLACE! YOU ARE LIKELY TO BURN UP A RIG, NO FOOLING!

IF YOU WANT THE JOKE PULLED ON YOU GO AHEAD AND TRY, I'LL BE LAUGHING! MORE SO IF YOU BUY ONE OF THE COLOR KITS SOMEBODY OFFERED ONE TIME.

THERE IS A SUCKER BORN EVERY MINUTE.
 
RE: The Slinky as an Antenna  
by WD8OQX on April 20, 2013 Mail this to a friend!
[quote]
W7AIT:
IF YOU WANT THE JOKE PULLED ON YOU GO AHEAD AND TRY, I'LL BE LAUGHING! MORE SO IF YOU BUY ONE OF THE COLOR KITS SOMEBODY OFFERED ONE TIME.
[/quote]

Are you saying that a PLASTIC one should be used? ;)
 
The Slinky as an Antenna  
by F6FLH on April 20, 2013 Mail this to a friend!
Have try a vertical slinky around a fishing rod ( 6 meters hight ) and same horizontal slinky .Antenna is like Up and Outer antenna with 8m of twin 450 Ohms : results are not fantastics but for field days it's ok( 30m to 12m bands.)Make your own and you know what to do with Slinky coils. 72/73 good DX.
 
The Slinky as an Antenna  
by K0IC on April 20, 2013 Mail this to a friend!
What seems to work for me is to use 450-ohm transmission line, cut the ends off and use twist ties, brazing might work better, and using a tuner. I might try a 4 to 1 balun and coax. It would work great in an apartment between two cement blocks so nothing has to be attached.
 
RE: The Slinky as an Antenna  
by K0IC on April 20, 2013 Mail this to a friend!
I use at least two slinkys on each side of the center, not just one slinky per side.
 
RE: The Slinky as an Antenna  
by W1JKA on April 20, 2013 Mail this to a friend!
My slinky gets good DX from the top stair landing to the first floor about 16 ft.,I found it resonate on each step with no tuner or trimming.Your results may differ depending on your QTH's tread depth.
 
RE: The Slinky as an Antenna  
by N0FPE on April 20, 2013 Mail this to a friend!
HAd one of these in the air 30ft up for a few years. It was terrible. Deaf as a post. It was stretched between 2 trees at 190ft apart. just didnt work. After reading more I saw that steel makes a really crappy antenna, radiates almost nothing. Maybe the solid brass ones will work better. All i know is I took it down and put up a Alpha Delta DX-CC (I know its not the best either) and the bands came alive. Now if I can hear them I can work them! And after tuning the DX-CC I have little need for a tuner. I tossed the slinky in the junkbox and will not give it to anyone nor would i buy another.

Dan/NŲFPE
 
The Slinky as an Antenna  
by K1CJS on April 20, 2013 Mail this to a friend!
There are some people who swear by compromise antennas--and some who swear AT them. That is all this can be said to be, a compromise between a really good antenna--and no antenna.

I see no reason to lambaste the slinky antenna or the people who want to experiment with them anymore than I see the need to lambaste anyone who loads up a bedspring--or a railroad track.

Slinky antennas exist, just like the Isotron antennas and the Buddipoles and all the other antennas that shoehorn full size antenna length into smaller areas. For some, that is all they can put up, for others, that is what they want to experiment with.

If it isn't your cup of tea, why not just say that instead of going off the deep end and proving what a narrow minded.... (insert your own descriptor here) you are!
 
RE: The Slinky as an Antenna  
by AA4PB on April 20, 2013 Mail this to a friend!
Taking measurements and presenting the results is now being "narrow minded"?
 
RE: The Slinky as an Antenna  
by KG6WLS on April 20, 2013 Mail this to a friend!
It's a toy!!!!
 
RE: The Slinky as an Antenna  
by WG8Z on April 20, 2013 Mail this to a friend!
It never ceases to amaze me.
 
RE: The Slinky as an Antenna  
by K9MHZ on April 20, 2013 Mail this to a friend!


Hold on a minute....I need to get some popcorn. This thread ought to be good.

 
RE: The Slinky as an Antenna  
by K1CJS on April 20, 2013 Mail this to a friend!
>>Taking measurements and presenting the results is now being "narrow minded"?<<

Didn't say that. Said that going off the deep end was.
 
RE: The Slinky as an Antenna  
by K1CJS on April 20, 2013 Mail this to a friend!
Sorry... My first reply was directed at the first responder, not the original poster. You see I have the _bad_ habit of reading everything before I respond....
 
RE: The Slinky as an Antenna  
by W7AIT on April 20, 2013 Mail this to a friend!
LOL!

 
The Slinky as an Antenna  
by N7KFD on April 20, 2013 Mail this to a friend!


I used to use one "stair portable" it was a lot of fun! Hi Hi!

 
I'm taking mine down  
by WB9QEL on April 20, 2013 Mail this to a friend!
Other than Slinkys store in less space, I see no good reason to use them instead of wire.


Dick Reid, KK4OBI 14 March 2013


__________________________________________________


You hit the nail on the head with your article comments above Dick. I'm taking mine down.

Great article and very informative!

W9ZXT

 
RE: I'm taking mine down  
by KD8MJR on April 21, 2013 Mail this to a friend!
I have owned three antennas over the years

First a slinky

Then a G5RV

And later a Steppir 3el with 30/40

After I moved from the sliky to the g5rv I finally realized that the bands had more than one or two people on them each day !
When I got the Steppir it was like the deaf man was cured and could hear again.

When I compare the slickly directly to the stepper my band scope goes from flat on the slinky to a ton of mountains peaks on the steppir
 
RE: The Slinky as an Antenna  
by N8NSN on April 21, 2013 Mail this to a friend!
It depends on what one wants to hear on how "good" an antenna is. I like to frequent an AM phone net on 40 meters. The stations on the net are anywhere between 50 to 350 miles out. Well, my resonant dipole at 35 feet hears them OK, but a lot of "out further" stuff piles in along with a noise floor of s4 average. Switch to a vertical and hear out even further and noise floor s2<3.

Then: two Slinky. Three feet of #14 solid brazed to each slinky and on each end. Connect in center with 75 ohm cheap CATV coax, install in attic at about 16 feet high, and it is resonant on 40 meters and is NVIS receive attenuated heaven. The net guys 50 to 350 miles out are S9 to 50db over s9 and the noise floor is s0<1.

So, if a pair of slinky is all that one can have... It still beats nothing at all.

The 3 feet of wire straight out on each end of each slinky was just for convenience, but turned out to "just work out" for resonance and a reasonable SWR with 75 ohm coax feed 25 feet in length.

_____\\\\\\\\\\\\\\\\\\\\\\\\\\______ ______////////////////////////______

Looks like this^^^ sort-of

So as the call suggests: N8 never say never.
 
RE: The Slinky as an Antenna  
by N8NSN on April 21, 2013 Mail this to a friend!
Oh yes, forgot to mention, though should have been obvious. Sometimes attenuation at the antenna is exactly what a receiver needs to perform a desired function.

Also, thank you for investing the time and energy to formulating your numbers and writing a great observation article. Though to me, efficiency and resonance are relative terms to either side of the equation. IOW resonance in a system coupled with a negative efficiency of an antenna, may indeed be the desired result.

You'd be amazed at what you will hear below one MC with 6000 feet of wire buried 2 feet under ground !
 
The Slinky as an Antenna  
by K3SX on April 21, 2013 Mail this to a friend!

When I first moved to what was then a rental home I had the real estate to get on 160 80 and 40 meters but not the permission to erect permanent antennas. I put up a bandswitched Slinky vertical for 160, 80 and 40 M. I also put up a 7 Slinky "Beverage" receive antenna. I used that combination for 2 seasons and worked all 50 states and countries on other continents too.
Instead of just tearing down anyone's work try it yourself. When the EWE low band receive antennas were introduced I tried them here in the rocky soil and they didn't work. The Flag and Pennant antennas worked very well.
Do it and prove it yourselves.
Thanks to the author for doing just that.
 
RE: The Slinky as an Antenna  
by KD8MJR on April 21, 2013 Mail this to a friend!
I think most Hams have tried a slinky at one point or the other and your going to be hard pressed to convince them that it's any good.
I am not tearing down the authors work but simply pointing out my own experience! I admit that personally I think it's a bad idea to give new hams that may be reading this the idea that a slinky makes a good antenna and that a lower noise floor makes it useful for some things. If you want a lower noise level then just turn on some attenuation on your radio and slow the AGC down. I do that all the time with QSOs and I can hear a round table of strong stations with almost full quieting and a lovely 59+ signal.
My basic point would be that if you can put up a slinky you can most likely put up a G5RV and between those two the G5RV wins hands down by a mile.
 
RE: The Slinky as an Antenna  
by KD8MJR on April 21, 2013 Mail this to a friend!
Sorry saved the above with out finishing.

I believe the OP point was that the slinky sucks, and in that regard I agree! Other posts saying its good in certain situations is just misleading a new Ham into a newbie trap. Get a wire antenna if that's all you have space for or cash for and give the slinky to a kid.
 
RE: The Slinky as an Antenna  
by W4KVW on April 21, 2013 Mail this to a friend!
Let's see,Top of the stairs for the upper bands & bottom of the stairs for the lower band or ground wave maybe??? That could be stretching it I guess! LOL {:>)

Clayton
W4KVW
 
RE: The Slinky as an Antenna  
by W4KVW on April 21, 2013 Mail this to a friend!
Let's see,Top of the stairs for the upper bands & bottom of the stairs for the lower band or ground wave maybe??? That could be stretching it I guess! LOL {:>)

Clayton
W4KVW
 
RE: The Slinky as an Antenna  
by N8NSN on April 22, 2013 Mail this to a friend!
" I think it's a bad idea to give new hams that may be reading this the idea that a slinky makes a good antenna and that a lower noise floor makes it useful for some things."

It's an even worse Idea to NOT inform new hams that there are ways to attenuate signals before they even reach the first I F in a rig, without buying an attenuator (good ones can be costly).

"If you want a lower noise level then just turn on some attenuation on your radio and slow the AGC down."

What if someone were to want to work an AM Phone net on 40 meters (yes, I think that was mentioned) and the receiver is an old SX 71 without AGC accessability?

I think it's a poor idea to have new hams thinking it is important to set up a station that MUST have all functions of making a contact happen "at the rig".

Giving the idea that there are MANY avenues to any desired result IS a good idea. Having a few things simply "not work out" is a GOOD thing. Real learning and growing is achieved through hands on practice and mistakes inclusive. Or are we only catering to the plug and play ops of the day?
 
The Slinky as an Antenna  
by NQ3M on April 22, 2013 Mail this to a friend!
The quality of Slinkys have been eroding as of late. Old bed springs from the dump on the other hand are still showing promise, unless they were made in china as well.
 
The Slinky as an Antenna  
by XE1UFO on April 22, 2013 Mail this to a friend!
Dick Reid, KK4OBI:

Thanks for your interesting article.

I wrote an article here many years ago on Slinky® antennas (http://www.eham.net/ehamforum/smf/index.php/topic,55762.0.html). In that post, I mistakenly said "15 feet per side", when I meant total dipole length. The best results I have had are between 7-8-foot stretch per Slinky®.

1. The slinky antenna will, of course, never be as good (effecient) as a full-size dipole, or a good multi-band vertical with proper radials under it. It is a compromise antenna. But that is exactly the point of trying a properly built Slinky® antenna. Get something up to get on the air, when you have no other possibility. Think for example: A hotel room with no balcony, or even a window that opens.

2. As Jimmy, N8NSN, so rightly mentions, try your experiment again with a 3-foot wire on each side of center, and another 3-foot length on each end.

3. In one rented home we lived in, I barely had enough room for a 40-meter dipole. Our national emergency SSB net here is on the low end of 80 meters (3.690 Mhz.). My tuner refused to load it on 80, but then I added a Slinky® to each end, each stretched 8 feet, and I could easily load it up and check into the net with good signal reports. And even worked a lot of 80-meter DX with it. Did it compare to my 130-foot doublett I now use? No way! But it got me on the air.

73,

Steve, XE1UFO -- KA5SUT -- 6H1UFO

 
The Slinky as an Antenna  
by KC8ZEV on April 22, 2013 Mail this to a friend!
Truth in advertising...."A slinky, a slinky, a fun and wonderful toy! A slinky, a slinky, fun for a girl and a boy!"

For the cost of a slinky, a longwire will perform better. Period. End of discussion.

Now if it is the purpose "just to see" what one can cook some RF off of, by all means, load up the slinky.

I believe it would be more fun to take a slinky to the mall and put it on an escalator than load RF into it.

But that is just me.

73
KC8ZEV
 
RE: The Slinky as an Antenna  
by K9MHZ on April 22, 2013 Mail this to a friend!
I remember the "Slinky Dipole" being sold commercially by more than one vendor over the years.

Not surprising then, to see Isotron antennas being sold even today. Now THAT is some snake oil.

 
The Slinky as an Antenna  
by KB2DHG on April 22, 2013 Mail this to a friend!
Wire works BEST!
If you want a multi band antenna there is no substitute for a G5RV!
105 feet across thats 52.5 feet each leg ( make it a little longer to twist the ends around an insulator)and 31 feet of 450 ohm ladder line and your working DX all over!
Keep the coax from the ladder line as short as possable...
I have worked with this antenna for YEARS and have great results. OH and save your money, build it yourself for about $25
 
RE: The Slinky as an Antenna  
by XE1UFO on April 22, 2013 Mail this to a friend!
Of COURSE wire works best! You just don't get the point, do you?

We are talking about something we have tried and used WITH SUCCESS, when there is no way, no space to get up a normal wire antenna. I am NOT replacing my ladder line-fed 130-foot doublet @ 50 feet, with a Slinky® dipole. I am not a moron.

And for portable when I do have the space, I also have my tiny NorCal doublet rolled up in my backpack.(http://www.norcalqrp.org/files/NorCalDoubletAntenna.pdf)
 
RE: The Slinky as an Antenna  
by K5LXP on April 22, 2013 Mail this to a friend!
Of course slinkies "work". After all, "Everything Works" [N6BT]

There is nothing you can do with a slinky that makes it a better antenna than plain copper wire. Even if you stretched the slinky out straight, it's steel wire. So it *can't* even be as efficient as straight copper wire. In the way most hams deploy slinkies they are worse than plain wire.

http://www.eham.net/ehamforum/smf/index.php?action=printpage;topic=65811.0

As I mentioned in the above thread, if the goal is to make contacts with unusual objects there's a contest for that. Other than this, you won't find a valid technical reason to use a slinky as an antenna.


Mark K5LXP
Albuquerque, NM
 
RE: The Slinky as an Antenna  
by K1CJS on April 23, 2013 Mail this to a friend!
"For the cost of a slinky, a longwire will perform better. Period. End of discussion."

Sometimes I think people forget that ham radio is a hobby, and that experimentation is fun! Sometimes it's a hobby with a purpose, but nonetheless, STILL JUST A HOBBY!
 
The Slinky as an Antenna  
by KC8ZEV on April 23, 2013 Mail this to a friend!
If everyone in Amateur Radio contnued to view it as "just a hobby", there would be no Icom, Yaesu, Kenwood to name a few. We would still be using cat whiskers and spark gap transmitters. Quite a difference from a few hours in the evening or weekend experimentation to full time engineering/r&d/production and support. Give the much needed credit and respect to those who take it seriously and have dedicated their careers to it so others do not have to and treat it as "only a hobby".

The Slinky is a marvelous feat of 1940's toy engineering. Certainly has been discussed and disputed countless times on Eham as an antenna.. Has anyone experimented with loading up a "Radio Flyer" tricycle or wagon? Will be looking for the wagon and tricycle antennas at Dayton.



73
KC8ZEV
 
RE: The Slinky as an Antenna  
by N1DVJ on April 23, 2013 Mail this to a friend!
Years ago I had a friend that told me slinkys suck. But he blamed it on the material, that it was 'resistive' at RF.

While almost anything will work as an antenna (there's a group in Texas that regularly has a contest using 14/3 romex and light bulbs in a standard ceramic socket) when something fills a need, use it. I was blasted once because I told someone to 'get on the air, even if the antenna works like crap'. A poor antenna is still better than no antenna. And a Slinky can fill a need. Like on a simple piece of 1x4 wood stuck out the window of an apartment building and hanging down from the 30th floor, tuned by a fishing reel.

Hey, if it works at all, you are better than nothing. I kind of sick and tired of the CB mentality crowd that feels that antennas have to be perfect or they suck. Heck, I've been camping and hooked to an electric fence with my MFJ tuner (I DID make sure the fence was inactive before I clipped on!) to make contacts.

Now, I never tried it, but I have seen 'plated' Slinkys for sale for use in antennas.

 
RE: The Slinky as an Antenna  
by K1CJS on April 23, 2013 Mail this to a friend!
"If everyone in Amateur Radio contnued to view it as "just a hobby", there would be no Icom, Yaesu, Kenwood to name a few."

Oh, please. Don't be ridiculous. These companies fill a need, just as there are companies that fill a need for items for every hobby. I'm speaking of the guy who passes the time with the hobby with experimenting and learning, not the companies out to make money off of end user products.

Tell you one thing, the majority of the people who are saying here that using a slinky is ludicrous because it doesn't put out a good signal aren't making money off the hobby, they're simply purists that don't condone experimentation--seemingly of ANY sort.

Your remark about there being no Icom, Yaesu or Kenwood is so off base that it's not even in the baseball park--it's over in the football stadium!
 
RE: The Slinky as an Antenna  
by KD8MJR on April 23, 2013 Mail this to a friend!
I have no idea why some people are still trying to convince other people that a Slinky has a use as an Antenna.

If you are NEW TO HAM RADIO and reading this thread you need to know that you should never ever buy a slinky antenna. (PERIOD)

When I was a Kid it was always a dream of my brother and myself to become Ham Operator, this was when we were 10 years old playing with walkie talkies and CB radios and reading Lafayette Catalogs till our eyes bled. Decades later my older brother eventually became a Ham operator and I became a Ham several years after that. From the first day that my brother got his ticket he tried to persuade me to get my ticket. I told him I did not want to learn CW, I had no time for Radio, etc etc.

After about 2 years of futile verbal persuasion my brother sent me a surprise gift of a Kenwood TS-440S and a Slinky antenna and told me to hook it up and listen.

With great excitement I put up the Slinky at 30ft and stretched the crap out of the thing between two nearby trees and with great excitement had the whole thing working lickity split. I then spent the next week using my free time listening around the bands and in that whole week I think I heard 5 stations in total! My brother was of course hoping that his generous gift would rekindle my youthful lusting for Ham Radio but unfortunately because my system was Deaf it had the opposite effect.


End result was that I thought Ham Radio was Garbage and a waste of time and because of a Slinky Antenna I did not get my Ticket for an additional 18 months and that only happened because my brother sent me a G5RV and I finally realized that there was actually a lot of people transmitting and that I could actually hear Europe. That G5RV spurred me into getting my ticket, buying 4 other radios 2 Amps and a Steppir, all in fairly quick succession along with a lot of other goodies that my XYL is not happy about.

That’s how even a moderate antenna can make Ham radio Fun and exciting versus a crappy antenna like a Slinky or the equivalent 4 inch Nail can have the opposite effect and suck the Fun and the interest right out of the Hobby.

If you already have a Good Antenna then by all means go ahead and experiment with Nails, Slink’s and wet noodles but if you’re a new to Ham Radio get a good wire antenna and set it up anyway you can.
 
The Slinky as an Antenna  
by SV1ENS on April 23, 2013 Mail this to a friend!
I tried both long and short versions of the slinky in a dipole and "long wire" configuration on HF with extremely disappointing results...
I now beleve that the slinky antenna is a Ham urban legend...

73
Demetre - VE3/SV1ENS
 
RE: The Slinky as an Antenna  
by AA4PB on April 23, 2013 Mail this to a friend!
When I was a kid I became convinced that I could build a perpetual motion machine by using a generator to power an electric motor and the motor to turn the generator. I tried and tried but never could get it to run. Then my dad came along and said I probably needed a starter to get it up to speed so he helped me attach and electric drill to start it spinning. As soon as I disengaged the drill the thing quickly came to a stop. Then my uncle (a mechanical engineer) came along and explained things like friction, loss, and efficiency. I then understood that it would never work.

I guess I had fun building and testing it but I could have saved myself a lot of frustration if I had checked with my uncle first. Sometimes knowledge and an understanding of theory is valuable.
 
RE: The Slinky as an Antenna  
by KD8MJR on April 23, 2013 Mail this to a friend!
"I guess I had fun building and testing it but I could have saved myself a lot of frustration if I had checked with my uncle first. Sometimes knowledge and an understanding of theory is valuable."

I did the same thing when I was about 12 years old. You should thank your stars that your Uncle did not talk to you at the start because the actual experience gained is the real Gem!

I have a few bright friends who come to me every once in awhile with some form of perpetual motion Aka free energy scheme and it seems that no matter how many times I tell them "You can't get something out of Nothing" they just continue to dream this stuff up!
Maybe if they had spent a full day like you and me and built one of these devices they would have actually believed it and stopped wasting their time trying to figure out even more elaborate free energy devices.

 
RE: The Slinky as an Antenna  
by N4UE on April 23, 2013 Mail this to a friend!
Great discussion. Although I have never tried a Slinky, every time I open the cattle gate, with it's 2" diameter coil of springy wire, I wonder.......

Actually, 'horse' fence antennas seem to work well. Go to your local Tractor Supply and check out the 'rope with conductors'... saw some pretty nice 'egg' type insulators for cheap there also.....Just strung 500' of the 'rope' electric fence wire. Not as an antenna, but something the cows could see! ha ha
ron
N4UE
 
RE: The Slinky as an Antenna  
by W5TTW on April 23, 2013 Mail this to a friend!
A slinky is like a mother-in-law. You always have the urge to push it down the steps.
 
RE: The Slinky as an Antenna  
by SV1ENS on April 23, 2013 Mail this to a friend!
Speaking of strange antennas, when I lived in a high rise building that was build like a faraday cage I desperately tested many "condo" antennas with the same poor results, I finally tuned the aluminum window frame and worked south America on PSK QPR :-)

Kudos for radiating materials !! Slinkies not being one of them...
 
The Slinky as an Antenna  
by KE8EC on April 23, 2013 Mail this to a friend!
Amateur radio is like a lot of hobbies, there is always someone upset because everyone will not do things just like he does, buys the brands he buys, etc etc. if the guy wants to build a slinky/dipole/beam/vertical for cryin out loud, let him do it.
 
RE: The Slinky as an Antenna  
by K9MHZ on April 24, 2013 Mail this to a friend!
Nobody's demanding that people should not do something....that's not the point.

The rub is in how it's presented. Yes it's a hobby, so therefore many won't have the savvy to critically evaluate some newfangled gizmo, or super-duper discovery. Some even made money from the gullibility of others.

The OP nicely concluded a case that the Slinky concept is junk. The same could be said of loading up dog poop in your lawn....nobody is saying "stop", but most would say "stupid."

 
The Slinky as an Antenna  
by K7KEY on April 24, 2013 Mail this to a friend!
Why didn't you test the "Slinky Beam"? My three-element Slinky Beam, on a 12-foot pipe lashed to a fence post, works like a champ on the 13 meter and 9 meter bands. No rotor. I have it fixed to a weather vane so that my QSO's are always into the wind. Since the beam is mounted upside down, the wind generated lift actually lowers my takeoff angle.
 
RE: The Slinky as an Antenna  
by K1CJS on April 25, 2013 Mail this to a friend!
KF7Z, Wow! You just proved you are saner than some of the others on this thread. Fine bit of humor!
 
RE: The Slinky as an Antenna  
by NZ5L on April 25, 2013 Mail this to a friend!
Thank you so much for your thorough, well researched presentation. I have always wondered if I was missing the boat for an easy multi-band antenna by not trying this approach. Thanks to your article, I see my gut feelings were indeed justified. You have done the ham community a favor.
 
The Slinky as an Antenna  
by AC8NS on April 25, 2013 Mail this to a friend!
I liked the reply by N1DVJ on April 23, 2013:
"<snip> ... Now, I never tried it, but I have seen 'plated' Slinkys for sale for use in antennas."

Yesss! Pop on over to one of those Golden Ear audiophile websites (any will do) for inspiration on just how gullible the public really is. Then you can start a business selling Slinky Plated Antenna Kits. REAL OFHC (oxygen-free, high-conductivity) copper plating, with optional silver and/or gold plating on a SOLID STEEL spring for compact storage yet quickly extendable installation. Sold with optional EZ Tune silver-plated antenna tuners, and mellow-sounding 24K gold-plated antenna tuners.

Hop - AC8NS
 
RE: The Slinky as an Antenna  
by K9MHZ on April 25, 2013 Mail this to a friend!
Yep. Veering a bit, but I never get enough of the types who spend $$$$ on anything made by Monster Cable for their audio setups. Sure, speaker cable needs to be bulky, but scientifically designed twists in digital cable, sealed with nitrogen, and on, and on. Throw in a glossy brochure made out of heavy card stock, with pictures of some unshaven artsy looking guy thinking deep thoughts (he's way smarter than you and me) about cables, and you've got a slick marketing scheme that brings in buckets of wasted cash to Monster.

 
RE: The Slinky as an Antenna  
by K1CJS on April 26, 2013 Mail this to a friend!
You ain't just whistling Dixie, MHZ. I went to a store to get some speaker wire some years ago, and had the salesman tell me that I was wasting my time looking at 18 ga. zip cord when there was specially made wire that would work much better.

All I did was ask him whether he thought the store display pieces sounded good--and he said yes. I went over and looked at the connections--he tried to stop me--and guess what? Those speakers were connected with 22 ga. zip wire. Talk about an uncomfortable salesman? YES!
 
RE: The Slinky as an Antenna  
by N1DVJ on April 26, 2013 Mail this to a friend!
I agree about Monster. They are good quality cables but the hype... Heck, depending on conditions you could use a short length of wire-wrap wire and couldn't hear the difference. It's all about impedance and the damping factor. Low oxygen? Give me a break...

Although I have to admit their cables that use high numbers of fine wire to meet the same gauge as other cables are nice. But STRICTLY from a flexibility standpoint, NOT from an audio performance standpoint.

But plating on antennas is far from hype. When I mentioned the plated slinky I wasn't referring to some kind of 'golden ears' type magic. While I never measured one, since I don't have one, I was told the slinky steel is very high resistance and the plating was simply chrome. And it reminded me of a problem I had with a Larson 5/8 wave Kulrod years ago.

I had one of the Kulrod plated antennas. Hard steel whip that had multiple platings on it with at least one layer of copper covered with chrome. Worked great. But over the years performance went to the basement. At first I thought it was the coil, so I tried a new one. No help. So I ordered a new whip. One of their 'plastic' whips. Worked great. So I started playing around.

I set a field strength meter on my wifes car and measured both setups. When I transmitted after tuning the antenna. one was almost 4 times the meter deflection difference, all else being equal. By swapping back and forth I tracked it down to the whip. And yes, both antennas were tuned to minimum SWR. How could a metal whip be that much different?

Then I examined the metal whip closely. It was pitted and in some spots it even looked like the chrome was 'peeling off' leaving an ugly underlayer exposed like a bad scab. The only thing that makes sense is the chrome on the surface carried the RF efficiently while the underlayers were pretty much a resistor with minimal, or at least poor, radiation.

Since then I still love the Kulrod for a single band 5/8 wave whip, but I never bought another chrome plated Kulrod, I always bought the colored whips. Larson used to sell them (and the coils) in a variety of colors, but I guess now you can only get them in black.

A guy that runs a radiator shop told me it's something weird with the acid rain and the 'other' chemicals they use for road salt in New England. Whenever he replaces a radiator with a generic one he always used to paint them with a lead based paint (used to, now I think he uses some kind of epoxy paint) that still allows for efficient heat transfer but is corrosion resistant, otherwise they don't last. Radiators untreated here in New England tend to corrode out the thin metal fins. They loose efficiency but don't leak. Cars overheat and shops with untrained idiots keep testing cars with pressure test (for $60 a pop) and saying nothing is wrong but they swap out thermostats as a shotgun (another fee, of course) but if they would just run their finger on the radiator the cooling fins will crumble away.

For some reason A/C condensers don't have as much of a problem. But if you buy an aftermarket radiator, like from one of the 'high performance' shops for race cars and use it on the street...
 
The Slinky as an Antenna  
by K1CJS on April 28, 2013 Mail this to a friend!
I think that too many are losing sight of the conclusions of this article.

"Other than Slinkys store in less space, I see no good reason to use them instead of wire.

And if you have an antenna tuner, all bets are off. Why mess with a Slinky? You can work the HF bands with a wire, say 25 to 40 feet long, in the rafters, under the eaves, draped over something or tossed up in a tree. Go for it! Hams even report making contacts with tuners by loading gutters, ladders, metal sheds, fences, even cars."

It doesn't seem that people are condoning the use of slinkies as much as they're saying that it is fun to experiment, no matter what you use to experiment with.

I still remember articles here, on other sites and in magazines about hams experimenting with a 100 watt lightbulb on a fence post, hams wiring up two twin bedsprings in a dipole configuration, another loading up one of those stainless steel mobile homes, and so on.

The bottom line is that it's FUN! Fun to wire it up and see what you can get, fun to see if you can discover a new way of fandangling an antenna, FUN TO SEE IF YOU CAN INVENT A "RIDICULOUS THING" ANTENNA THAT CAN WORK even if it works poorly at best.

It just seems that there are way too many straight laced 'purists' here than either don't see that fun--or want to eliminate it altogether, and that's sad. 73!
 
RE: The Slinky as an Antenna  
by KO3D on May 5, 2013 Mail this to a friend!
"Other than Slinkys store in less space, I see no good reason to use them instead of wire."

This article is 19 days too late for April Fool's so what's going on? Where can you even buy a metal Slinky these days.

"Other than gutters are already attached to your house, I see no good reason to use them instead of wire."
 
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