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View Full Version : New inverted L 160-20 meeters.



PA5COR
07-31-2011, 03:19 PM
Took down the 66 feet Inverted L wednesday, and put up the new one.
Today did the last work, now it's 77 feet high and 77 feet wire slanting to 40 feet above ground.
It;'s too long for 160 but i'm using the MFJ 998 1.5 KW autotuner, this way on 80 and above the tuner has no problems matching it with the Heathkit SB-1000 P.A..

The vertical section starts at the bottom with 3 1/4 inch tubing titanex quality, ends with 1 1/4 inch on top.
Wallthickness 2.5 mm ( 1/10 inch).

Difficult to see in the piccie but on top 3 wires, one the isolated copper wire for the L section, and 2 kevlar wires guying the top.
25 feet lower 4 uy wires also kevlar, and at 20 feet support at the roof edge, and at 13 feet an stainless steel mount, at the bottom the isolator and feed point.

Made 2 dB difference ( stronger) with the local and medium distance stations.

Still need to put the wire higher, will do that tomorrow.

KG4CGC
07-31-2011, 03:29 PM
Fantastic! I've grown to appreciate your antenna articles more and more.
Thank you for posting.

PA5COR
07-31-2011, 04:23 PM
Thanks Charles, my radio's mght be so so, but i rather put my effort in my antenna's.
Total cost of piping clamps and self tapping screws, Kevlar guywire about 300 euro's
Will keep the old one for our hollidays or sell it, dunno yet.
It was good enough to work lots of USA/Canadian stations in SSB the last winter.

The saga continues...;)

KC2UGV
08-01-2011, 09:07 AM
Hopefully, I'll be able to retire, so I can play with antennas. Right now, it's "What works, get it up, and use it"

PA5COR
08-01-2011, 10:48 AM
Hope you get things done then Corey.
Never had the time to do this tinkering when i worked, 60 -80 hours on the job does take the fun out of it.

After i got the word i would never work again, i found the time to do all i put off, just the back does not always want to comply with my physical wishes...

For that we can make stuff helping us making things lighter.
:)

K7SGJ
08-01-2011, 11:15 AM
Out of curiousty, were you able to A B the antennas to get an idea of how much of an improvement the new antenna is?

PA5COR
08-01-2011, 12:23 PM
Yes i could Edward.
The old one which was extensively described in an older thread with pictures here in the antenna section was up for over a year.
We have a bunch of 160 meter guy's here anywhere from 20 miles to 60 miles away that kept their setup the same before and after my setting up the new L, and the ones that helped testing have a consistent signal here on the ground wave.
That gave me the 2 dB extra gain in ground wave rounded off between all the people that took part in the test.

It is the practical over the air testing i prefer, software modelling is nice if you toy with some idea's but in the end the real world tests will give you the results.
What we found out is that if your ground wave gets stronger, that also translates in a better skywave roughly in the same ballpark in gain as the ground wave gain.

And no, I'm not an antenna guru, just been trying to fathom them since before 1977.
And help from ON4UN, Rothammel, ARRL antenna books, RSGB antennabooks, and mostly just from making them falling flat on my face and learn from mistakes.;)

My plot of land is just 100 x 25 feet including the house on it, and for dx on 160 the verticals are the best choice if there's no room for other more elaborate antenna's.

Transmitting is not the real problem, reception is.
For that we have the K9AY, or EWE, or Flag antenna's to reduce noise.
Better is living somewhere where there is no noise, but i just live on the edge of the small provincial town, so i have to do with that, and the EWE antenna.

Not ideal, but the old setup made lots of nice qso's possible with the USA/Canada etc in SSB.
Add cw and you gain instantly 10 dB ;)


Just trying to get a good signal out from a small plot is a challenge in itsself.

NQ6U
08-01-2011, 12:34 PM
Cor, with the vertical portion of the antenna so close to your house, how did you run the radials? It's obvious you couldn't have buried all of them.

KK4AMI
08-01-2011, 02:19 PM
That is amazing work. That roof looks pretty steep. Don't fall or injure yourself. Are all of those antennas yours? Thinking in nautical terms is your house now rigged as a schooner or barque ?

PA5COR
08-01-2011, 03:09 PM
LOL :)

All radials are buried under the soil of the garden, through the basement to the front garden, sneaked radials outside my plot to neighbour plots with their permission, and when they broke up the dead end road in front of the house put in some copper there as well.
17 earth electrodes most 10 foot deep in the young silty sea clay here.

All antenna's except the small dish on the wall are mine, my dish is at the end of the garden ( motorised dish for sat TV).
The radial field isn't a nice circle, and not all radials are very long, but burying radials detunes them anyway so put in as much you can in any way or form you can, connect the ( stainless steel) kitchen sink, copper water pipes, house earth, and anything conductive to it.
I used the MFJ 269 analyser to see the resistance drop till the point of no return was reached ( 2100 feet copper wire).
Some wore was run on the fence , some woven in the fence, anywhere i could hide a wire there is one....

What is not so good visible is the OCF ( FD-4) with coil and wire from 160 -10 meters it runs from just under the 5 element 6 meter beam to the rows of housing in front and behind me, look up my call on the Zed and click satellite piccie of my situation.

I regularly climb the roof through the window in the roof, the tiles can be removed partly and for a kind of ladder then.

That's how i got it all on the roof in the first place ;)
I think it is a 2 master, no, 3.... eh, whatever.... ;)
The Vertical section has kevlar/aramide guy wires thin but very strong but not good visible on the piccie.
Total cost 300 euros all included.
Last piccie you can just see the back of the MFJ 998 1.5 kw autotuner feeding the L.
Still a mess to clean up at the feed point, but that can be done this week, getting the radials under the pavement.
Even in aa limited situation you can do some good things antenna wise, i admit that the number of antenna's might be a bit overdone if there is something like that....
But then i have a good relation with my neighbours ;)

suddenseer
08-01-2011, 06:34 PM
Awesome Cor! You, and down under Bob keep my attention. Now, let's see the smith chart (LOL)

KG4CGC
08-01-2011, 07:01 PM
Awesome Cor! You, and down under Bob keep my attention. Now, let's see the smith chart (LOL)http://i25.photobucket.com/albums/c79/bebop5/4a12f3d8.jpg

PA5COR
08-02-2011, 02:43 AM
You can pry the analyzer data from my cold MFJ 269 analayzer

Did some dx last night, conditions sucked, E layer spoiling conditions, just UK, Germany ( Berlin) and Europe general.
Till the E layer wasted conditions good results with 600 watts were very positive, good loud signals compared to the other guy's here.

Resonant frequency is 1450 KHz on purpose, so that working the L on 80 i don't feed it on the voltage point, but between the current and voltage point.

I'll be back with more rsults as they come in.
Most important time will be winter ;)