THE LEVY'S ANTENNA

Abstrct:

The story begin when I want to play with something different from the usual Ground Plane using my "T" self-made tuner, and 450 ohm balanced line.

The LEVY:

After a short phase of study, I decided to cut the dipole and the ladder line following the size of a G5RV and feed it like a Levy without a dedicated tuner like you can see in a old A.R.R.L. ANTENNA BOOOK, but feed it directly to the high Z soket of my tuner.

The idea of using these dimemnsions is not mine but come from an old article wrote by I0JFE (downloadable here) that I found on the internet, I would call brilliant: i cut one antenna, but it can work in two ways!

In our case the dimensions are 15.54 meters for the two half dipole, and 10.36 meters for the 450 Ohm ladder line ,all was mounted in inverted V configuration with the center of the dipole about 6 meter off the ground.

This is my levy !!!

Before put it "on air" I made a simple test if with the only balanced line connecting the tuner rolled up on itself i can heard something, the result was positive, then go ahead!

Now is on air and surprise i had some problem with RFI, on some band RF come back and in cw i listen the sidetone distrted when i stay at 25 or more Watt level, but I have to make more experiments using an artificial ground in the station, so it I had to adapt to operate QRP with 5 watts output power.

A "personal" method to pass trought the window during summer !!!

Just under the widow you can see the winter way to feed the Levy to my tuner !!!

The table below shows the results that I got to agree what happened in the Summer of 2012, during Winiter the only differecie i have saw more R.F.I. on 20 meters !!!

The measures of R.O.S. were made with the internal SWR meter of Ic 735!

For the curious situation in the various bands is that after 8 days of use:

I worked: I,F,DL,SP,ON,OM,LY,RA9,G,GU,GJ,GI,HA,OZ,OK,UR,S5,EI,9A,EA9,EA6,5B4,EU,HB9,ZA and Z3 (26 countries representing a quarter of the DXCCin 10 days).

I've heard: UN, K, JA, HC2, ZP and VE.

Revolution in my station for the occasion !

When receiving the pre tuning is more felt on dipole than when using the vertical, but don't need to run with the knobs.

Speaking about of stations that I only listened to Levy (UN, K, JA, HC2, ZP and VE)their signals was lower by 2/4 points of S-meter to the vertical, the Europeans stations with which I made QSOs were essentially the same on both antennas the times I switch it.

With signals from Europe I've never listen with the levy and not vertically, and vice versa, but I need did comparative tests in transmission.

Using the Levy at times I made QSO with stations with which we exchanged both reports of 519 and the QSO very easily to finish, sometimes I exchange report of s-meter,4 points lower than mine.

Only one time I had to repeat my name 3 times, due to the high level of QRN that carries around a thunderstorm, operating QRP these things are felt much!!

In any case, I think a good antenna to make your firsts QSO in the European context, but can be shortened depending on your available space.

Here it is seen from the ground !

With the presence of high wind I saw the ladder line move, but with no observed fluctuations of S.W.R. or noise in speaker!

After a week of use, and about eighty QSO, I asked a few questions about the goodness of the stations of my correspondents:

What kind of receiver and filters used?

But they heard me?

The operator was awake?

How many background / industrial noise local area has the other station?

This last question, I am reminded of an account important thing on VHF and UHF and shortwave is often assumed that what the "local noise".

In practice the rule to make QSO in QRP isn't calling, but answer to the stations that show good signals , so it would be on paper, but sometimes I not to make QSOs with stations arrived to me like a gun S9 in contest !!

We must say that is pretty camouflaged !

One last thing to tell you and that in some QRP QSOs made my correspondent lowered the speed transmission and making pleasant exchange of information after the report, name and QTH !

I'm thinking about doing the next national contest HF QRP with this antenna !

And try to run it as a classic G5RV, one day ....

The G5RV:

After about six months of use I decided to convert it to Levy G5RV as I had originally thought, also because I have two HF transceivers and 2 tuners, I use them at the same time to make comparative tests on the polarization of the received signal.

Compared to Levy I just made some changes, adding a plastic box at the end of the ladder, where do I connect to the coaxial cable and wrap the choke, I also dug a channel where I route the coaxial cable along a couple of meters deep about twenty centimeters in the garden where the cars pass.

In the box I connected the cable lugs screws and cable ladder which is fixed to a piece of tephlon used to hold fixed connections between the central and the shield thus avoiding short circuit, if I pull the power cord or ladder.

I made the choke winding 10 turns of RG 58 on a Mylar ring of diameter 15.3 cm, obtained by folding a sheet thickness of about one millimeter, the cable then the fact arrive in station without cutting .

The choke and the little box uner the snow !

The first tests in reception I confirm what I had read on Eham.net about this antenna: in reception is noisier than my Butternut HF9 a couple of points and this on all ranges, although I noticed that listening to the QSO in 40 meters when there is traffic and someone wants to enter the QSO I feel it the first time around, and the other stations not always, this with both my antennas.

Also in reception you do not notice the difference with and without the tuner, so I consider it good for a SWL plant, the agreement can be easily implemented in transmission ROS of 1:1 is reached on all ranges but I depend on the kindness of your tuner.

At the European level a lot more listening stations with the G5RV that with HF9, defends himself well in listening to right, I listened CO, TI and W in the early days, during the first weekend I was very happy because contrary to my expectations, I made a qso with an American on 40 meters with 30 Watt in CW, because I had the final not fully tuned, using my Kenwwod TS 830.

The first thing that surprised me was, when listening to a station and its European dx pileup on 40 meters for almost an hour, with both the antennas I could see that the principle signals were more strong on HF9 that on G5RV as noted above, although with the G5RV listened many more stations who called, but for a certain period this station came better with the G5RV that with the HF9 of the usual pair of points.

After a few weeks of activity in 40 are 20 meters in the past where I have gotten some of the DX is in SSB and CW without much effort: PY, CO W3 and one thing that made me especially when I connected the island of Aland OH0 arrived on the G5RV and not on HF9, but also OH0 had a dipole, it happened to me also on 15 meters where one morning where a HA only came on a G5RV and a few KHz EA came on both the antennas on the evening of that same day I listened to a HC2 who came good on both antennas, but better with the vertical that I used to make the QSO.

In the light of the tests made I realized that a good station in HF, must be equipped on all ranges with two polarized antennas in a different way, because they increase the blossoming possibilities of making QSO, species in Contest more than to have large power, because I feel useless if you do not put me to call, then the golden rule of amateur is: LISTEN, LISTEN !!!

Other experiments in reception were made using the Ts 830 listening to the same station and switching the antenna on the various bands during the CQWW SSB Contest of 2013, in this table I show you the results.

As for the mounting I unfortunately had to deal with my QTH, in fact reading what the instructions say to that produced by the MFJ, which I used as a starting point for the installation, I did just the opposite, for example : I mounted it low to the ground and close to the wired net !

How to use a central insulator plate in matriale plastic that holds the contacts exposed to the elements, this thing is fine if you are portable where you work for a few hours or days, in a fixed installation like mine, it would be better to close the counted inside a box, so you do not have problems in case of snow or rain, as I mounted I do not seem very suffer !

The central part completely snowy impressive to behold but the ROS minimum is 3:1 !

From what I've seen so far I consider it a good antenna for portable operations and/or confined spaces, especially when you want to cover a little bit all ranges, especially because even if not perfectly fitted is giving me unexpected satisfaction.

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