DX-1 Vertical HF Antenna. Anybody here have one?

[KF6IRK]

I built a HF dipole with a couple 'Slinkies' several years ago. It worked OK on 40M, never tried it on any other bands. I never thought to build a vertical out of a Slinky either.

The DX-1 (below) looks like a cool antenna for Field Day, but kind of pricey for what it is ($103.50, including shipping). I guess the fiberglass pole is the expensive part

I already own two long telescopic fiberglass poles, and Slinkies are cheap, so I can build one for much less.

Have any of you used one of these (or something similar) for DX-ing? How well do/did they work?





The Coil 2 1/2" Tall. 2 13/16" in Diameter. Has 84 Turns. Each coil is 9" round (2.85" dia x pi = 8.949"). Take the 9" X 84 turns = 756 inches, divide that by 12, comes out to 63 feet total coil surface. The coil is made by 2000 James Industries, INC. - PO box 407, Hollidaysburg, PA. 16648. Safety tested - meets or exceeds ATSM f-963 Code. The coil is made of stainless Steel. Will Not Rust, Corrode or oxidize. The coil will handle 500 watts of RF.The coil will hold up in severe cold and hot weather. The coil is the antenna, and it is held on the telescoping pole by pressure from the base of the coil, which has a center hole that is slightly smaller than the outside of the telescoping mast bottom .The coil is hooked up by a 10 ga solid copper feed from the base where a SO-239 and a ground terminal are located.

Type: VERTICAL
Height: 20 feet
WEIGHT:
Telescoping Mast: 1 pound .08 oz
Coil: .66 oz
ASSEMBLED WEIGHT: 1.92 lbs

MAXIMUM POWER INPUT: Legal Limit
SUITABLE MAST MOUNT SIZE: 3/8 " to 2 1/2 "
MAXIMUM WIND SURVIVAL: (tested) 85 mph
MAXIMUM TEMP SURVIVAL: (tested) -29 deg
V.S.W.R. (with Antenna Tuner) 1.5 1 or better

SHIPPING WEIGHT: ( Including Shipping Tube*, Packing Material and Antenna coil, Telescoping Mast, (2) brackets) 5.5 pounds

PRICE------>> $ 75 .00 + $28.50 for shipping ($103.50)

* DO NOT THROW AWAY THE TUBE & ITS PACKING THAT IT WAS SHIPPED IN. REASON: You can put (2) 4.5" rubber pipe covers over each end and with 2 large dryer hose clamps and a heavy duty gate or screen door handle, you have a way to store and transport and protect your whole antenna system.

 

[K6BIG]

14k Scrap Gold Vintage G P Slinky in G E Employee Gift Canister RARE | eBay



IRK.... if you are going to make one... check above..
I know.. .aint cheap... but that is bad ass AU

woop
here is another
http://rover.ebay.com/rover/1/711-5...0001&campid=5336136228&icep_item=290943190491

and another

http://rover.ebay.com/rover/1/711-5...0001&campid=5336136228&icep_item=370840479836

hmmm


Big B

 

[w9cll]

It's always been my understanding that "slinkys" make really bad antennas.

 

[Moleculo]

Will it work? Sure! It's just a helical wound 1/4 wave antenna. Keep in mind that due to the long, skinny load coil this isn't a very efficient design, but it will work to have some fun with. One problem that arises from using a slinky is that the coils can flex a bit from wind, causing the inductance values to shift. This can play havoc on the impedance that your transceiver sees. Using a fiberglass mast will help reduce this, but it still could be a problem on the lower bands where your antenna's bandwidth will be very narrow.

Happy_Hamer built something like this by jamming the end of the slinky into an S0-239 and then running a ground wire of appropriate length. If you have a decent tuner in your rig you should be able to get on the air quickly and have some fun with it. Make sure and take pics and let us know how it works for you!

 

[KF6IRK]

On the slinky dipole, I did have to run some nylon rope (1/8") from the center out to each end to support the slinky elements. I'll see if I can find it and post a pic.

I just ordered 4 long 'slinky's from hometrainingtools.com $6.20 each + shipping, so it came to a little over $30. for four of them.



Description: Extra-long 7-1/2 cm diameter slinky specially suited to study longitudinal and transverse waves. 10cm long when compressed and extends to nine meters.


I'll try one of them on a 28' telescopic fiberglass 'pole' and report back on how well it works op:

 

[KF6IRK]

I found the old Slinky dipole after digging around in the garage a bit.





The SO-239 is mounted in a 3/4" PVC 'T' that I sliced the back side off of. The center conductor is strapped to one of the Slinkies, the shield strapped to the other.

I attached a couple of sections of 2" ABS outboard of the PVC 'T' to keep the Slinkies from becoming tangled when it's not deployed. The screws and nuts that attach the straps to the coils also secure the ABS sections to the 'T'.

I'll try to keep it handy so I can try it out on some other bands next 'field' opportunity.


The longer Slinkies should be here sometime this coming week, and I'll get to work on a vertical as soon as feasible ...

 

[W5LZ]

Best advice I can think of is to try one and see you you like it. Don't just see if it'll work, but use it for a period of time and see how it works over varying conditions.
I have a six-pack, and a quarter, that says that you won't keep it for very long because of it's superior performance and ease of use.
- 'Doc

 

[KF6IRK]

Well, I ordered four aftermarket 'Slinkies'® and they arrived a couple of days ago. I started gathering up all the components needed to complete this DX-1 'clone' project last night.

For the mast, I'm using a Golpher Pole®. It's a 20+ foot, 6-section, telescopic, fiberglass, wire installation tool. I've had it for over 20 years, so I don't remember the cost. The top section is .656" diameter, so it's pretty rigid, unlike some of the skinnier telescopic wire pulling tools on the market.

The radiating element/'Slinky'® is a United FCS003, Flat Coiled Spring that's 3" in diameter x 4" tall. They were purchased from Home Science Tools for a little more than $6.00 each. I purchased four of them, just in case this thing works well, and I can build some spares. If not, I can always use them for their original intended purpose - to amuse my family, friends or even myself :laugh:




I rough sketched the dimensions for the top and bottom coil plates on some paper-covered 1/8" plastic sheet. The outside diameter of the plates needed to be a tad larger than the O.D of the 'Slinky'®. Next, I drilled the center hole in the bottom plate with a hole saw and cut the rough shapes out with a band saw. The center hole in the bottom plate needed to be a little larger than the outside dimension of the bottom section of the mast. A 7/8" paddle bit was used to make the smaller hole for the SO-239 UHF connector.




I peeled off the protective paper and finish sanded the plates to their final dimensions, bent some Panduit® stainless steel straps around the edges of the plates and drilled the holes for these clamps. Four clamps were used to secure each end of the 'Slinky'® to the top and bottom plates with #6-32x1/2" hardware.






I drilled a 1/4" hole in the center of the top plate and installed a 1/4-20x2" bolt to keep the top plate securely positioned in the top section of the mast. In the event a capacity hat is needed, a cap hat can be secured to the top plate with the center bolt. Just install a short #12AWG jumper from the center bolt to one of the top clamps.




To keep the 'Slinky'® from becoming tangled up in itself, I found that it fits quite nicely in an empty JIF® 'Creamy' peanut butter jar. I guess you could use Crunchy (or even another brand) if that's your preference :tongue:




I picked up a different style of SO-239 connector, one without the panel-mount flange (my mistake in designing the size of the bottom plate too small), as the flange was too close to the 'Slinky'® element. Then, I soldered a 12AWG wire from the center pin to a lug that attaches to one of the clamp screws that secures the 'Slinky'® to the bottom plate. I used some serrated star washers to help grip (bond) the connection and included a ground tab, should the need for a ground or some ground radials be required.






So, that's pretty much what was done to construct this thing. When I have some additional 'spare' time, I'll hook it up to a radio and see whether or not this was a total waste of my time, or if it will actually be a decent [temporary/field day] HF vertical antenna op: