The multi band end fed antenna with a twist

[PA5COR]

INterested in getting a different antenna build i stumbled on another forum i come on a new design of the old trusty end fed antenna, older as me, but not with a 1:9 balum but a new design 1:49 balun and resonant wire after that multi band.

In my piccie you see the 800 watt balun 2 times FT 240-43-61 stacked together and taped with glass fiber tape and the windings, see here for more details

THis is for the smaller core the same as for the larger cores the ft 140 is smaller and good for 100 watts PEP.
Over the center conductor and ground you need a 100 or 150 PF 500 volt or beter 1000 volt condenser, to make 10 work better wire lenths for the different models here: http://pa-11019.blogspot.nl/2012/04/149-transformer-for-endfed-antennas-35.html scroll down a bit.
http://www.hyendfedantenna.nl/joomla/blog/17-multi-band-hyendfed.html here is the adress and site of the guy's producing them in the Netherlands for the ones that don't want to make one themselves but rather buy one.


http://pa3hho.files.wordpress.com/2011/10/1op50-trafo.jpg?w=367&h=348

[PA5COR]

Navigate the site for the end fed antenna for the reviews and practice tests, http://www.hyendfedantenna.nl/joomla...-hyendfed.html (http://www.hyendfedantenna.nl/joomla/blog/17-multi-band-hyendfed.html)
http://www.youtube.com/watch?feature=player_embedded&v=F7kbBDftRRc someone working with 2 watts from an FT 817 in Canada and someone maritime mobile in the Netherlands.

QSO on 20 with Arie, PD0ARI/MM out in the ocean near Rotterdam on 14208 kc at 0937 utc.
He's working with 25 watts while vy/ON5RZ/qrp/portable was putting out 2 watts!
Later on in the clip Rene, PD2RKG/M joins in driving his car on the motorway A12 near Rijswijck Holland.
Very good signal strengths from both stations as you can hear.

For members plagued with not too much space for an antenna this might be your solution.
Vertical along a fiberglass pole or in L form, sloper or straight it works fine.
Tested the balun on the piccie with 800 watts but that was really maximum power the core got warm with the processing on, so more realistic is 600 watts using processing.

Still enough to put out some serious signal, and get excellent reports.
Recieve was quiet, something i didn't expect from that antenna, since the coax will be used as counterpoise use a current balun near the set in the coax, i just wind some coax around a ferrite bar from an old radio for that.

No talk in on equipment was noticed, so neighbours happy and people in the house as well.

[NQ6U]

I don't quite understand the winding scheme, Cor. Is the cold end of wire A left unconnected?

[PA5COR]

Both cold ends come together soldered to the ground connection of the PL 259 plug, so each winding starts from the ground 2 coupling windings from the tip of the PL259 to ground and then the other winding to the antenna, twisted 2 windings with the couple in winding from the transceiver and 2 x 7 windings to the antenna wire.

[PA5COR]

I see my picture is missing.
Hoping resizing works...

[PA5COR]

Many antennas used for portable operation suffer from lack of effectiveness. That is, they don't produce the number of QSOs expected, as compared to operation from a home location. Most of the time this stems from the fact that the antennas used when going portable are intentionally simple, and because of this they don't put you few watts of where they belong.

One type of "simple" antenna used for portable operation is the vertical antenna. If used with a good ground system a quarter-wave vertical antenna can be very effective. But often portable use dictates an antenna that is not a full quarter wavelength long and a ground system that is far from optimum. Consider two things:
1) According to the ARRL Antenna Book, a quarter wave vertical antenna with fifteen 1/4 wave ground radials may have an efficiency of only 50%; with fewer radials the efficiency suffers even more.
2) Efficiencies of short mobile whip antennas listed in the same reference are often only 10% or so - and that is with a car body as a ground plane. With a poorer ground it is even worse! Unless you have a full-size vertical antenna with an extensive ground system you are converting most of your transmitter power to heat, not tickling the ionosphere.


One of the best choices for portable operation is the center-fed half-wave dipole antenna. It has the benefit of being very effective and not too difficult to properly erect. On the down side, it does require end supports at the right spacing and height. You need to contend with a heavy feedline at the center which has to be brought away from the dipole at right angles or performance will be degraded. Multiband operation is possible but the best way to do this with a dipole requires an open-wire feedline and a relatively complicated symmetrical tuner.

If you take a half-wave dipole, eliminate the feedline and feed it directly at the end, you have an antenna that has many of the advantages of the dipole with few of the limitations of other portable antenna methods. This antenna has been described for years in the ARRL Antenna Book and other amateur radio publications but it has received little attention lately.

Without the feedline the antenna is a snap to put up. Freed of the restrictions of the center feedline, the HyEndFed fits into situations that would be difficult for the dipole to handle. When erected well of the ground and clear of surrounding objects, it is as efficient as the dipole and it is effective because radiation from it is predictable so that the signal goes where you want it to go. No tuner, just hook up the coax and go.


Also, because it is only a single wire with a insulator and a little matchbox integrated in the second insulator the HyEndFed is lightweight and small so it is easy to store and transport - things to consider for portable use. It doesn't have to support a center feedline so physical strength is not an issue. A temporary portable telescoping fishing rod antenna mast can be used..

The total overall length of the HyEndFed is an electrical half-wavelength, calculated from the formula L (Ft) = 468/F(MHz) where L is the overall wire length in feet and F is the desired operating frequency in Megahertz.

Mono band version, good for 2000 watt.http://www.pa3eke.nl/joomla/hyendfed.html end of page testing with 2000+ watts

http://forums.hamisland.net/joomla/images/stories/BLOG/QRO-20m-small%20housing.jpg

[PA5COR]

http://www.youtube.com/watch?v=Ybbv_h1HFw0

For the doubters, here is a test with the hy end fed and a standard 1:9 end fed antenna.
The difference is clear.

[NQ6U]

Both cold ends come together soldered to the ground connection of the PL 259 plug, so each winding starts from the ground 2 coupling windings from the tip of the PL259 to ground and then the other winding to the antenna, twisted 2 windings with the couple in winding from the transceiver and 2 x 7 windings to the antenna wire.

I went and looked at the Web site like I should have before I posted, it makes sense now. I might try one of these on my autumn camping trip.

[PA5COR]

I was looking for a good camping/holliday antenna as well, the 5 band one that with a tuner will do all 80 and without tuner 40 to 10.

Just one point to hang up not 3 for a dipole ;) normally i took a full size OCF ( Fritzel FD-4 ) with me of 132 feet length and a ast collapsable of 35 feet and lotsa rope for the ends to be tied away.
Now just a 40 feet collapsable fiberglass rod will be enough and make an inverted L from it.

No radials to put up and coax fed.
;)

[NQ6U]

What's the deal with the choke he shows at the feed end of the coax? Is that on the shield?

[PA5COR]

Yes, the coax is used as counterpoise, so install a choke balun near the transceiver, 20 windings around a coke bottle or use a ferrite rod and put some windings aaround that a few feet away from your transciever.

[N8YX]

I believe this to be similar to the matching arrangement used in the Antron 99.

[WØTKX]

And the Par End Fedz. Be interesting to phase a couple of them eh?

[N5KAT]

Is this design using one type 43 core and one type 61 core in a stack? Or does this suggest to use either 43 or 61?

I built some variation of this and used a Micrometals type 2 core.

[PA5COR]

I made 2 versions with the FT 140-43 core and the hi power one with FT 240-43-61 core, the last one is over 2 inches in diameter or 61 mm size.

Type is 43 material, i stacked 2 on eachother for better and higher power handling.

You need only one core of the FT 140-43 material if you only use 100 watts PEP SSB, and 400 watts for the FT 240-43-61 core, stacking the cores or doubling them will almost double the power they can handle.
the 61 material might not have enough wide band properties, the type 43 does have that properties, type 61 has a higher Mu.
Stacking cores will raise the Mu and theoretically you can do with less windings, were it not this is a transformer 1:50 that needs to be kept in that way.
Testing the transformers with stacked cores they did just fine for 80 -10 meters, i could not detect much change from going 1 to 2 stacked cores.
The power handling just goes up, i put 800 watts into the transformer on 40 and 20 with the 2 stacked FT 240-43-61 cores and could not detect any real warming up.

So for a 100 watt PEP one core of the FT 140-43 material 36 mm diameter is enough, double that for 200 watt PEP or using digital full output modes.
The FT 240-43-61 core can handle 400 watts, double that for 800 - 1000 watts.
Keep the windings as stated to keep the transforming at 1:50.
For the high power versions use glass fibre tape to isolate the cores, and teflon coated wire best with teflon spaghetti over it for the high voltages that can be present at the top of the windings near the antenna output, half wave antenna = voltage fed.
I only used teflon coated wire for the windings, but with glass fibre tape, and had no problems running 800 watts from the Heathkit SB-1000.

[N5KAT]

Thanks for further comments. I will try this and I will likely use my T-200-2 cores, since I have them in stock.

My question related to the "43-61" designation,. Type 43 and type 61 are two different mixes, with different optimal frequency ranges.

http://www.fair-rite.com/newfair/materials.htm

I never saw these designations combined in the way you reported. I thought you were suggesting to use one each of 43 and 61 cores.

I had the PAR Endfeds 25W three bander and it worked quite well as a portable antenna. Since I like to use my old 200W FT-102 at home, I need to construct a higher power version, so very glad to find your project report!

[PA5COR]

No thanks needed, we're here to report our findings and experiments.
I always took my 135 foot OCF antenna with me on holliday;s so this looked to be an interesting twist to get a decent antenna shorter as the Off center fed antenna with us, and high power as well.

If used with 20.5 meters of wire it'll work 40/20/15/10, no coil needed.
As usual, keep the wires a bit longer and cut for resonance.
Done well, swr would be very good and no tuner is needed.

Getting 41 meters of wire on it is the next try, see if it works on 80 and above...