[OKDXA] Lift Truck - 160 Meters

[Jay Bromley]

Alan,
In some cases 80 is not too short if you have some top loading.  I had only 
a 56 foot Rohn with a 12 element LP on a 30 foot boom.

By adding a loop to the bottom shut wire, I use my MFJ as a grid dip meter 
to see where the tower was naturally resonate.  It was below 160 and in the 
broadcast band.  In fact the MFJ did go low enough, but low enough to see I 
had more than enough top loading.

With this setup I change out my antenna at the top many times which royally 
screwed up my 160m performance.  Gong to a C19XR Force 12 was the pits, the 
elements are insulated from the boom and no DC grounding which hurt my top 
loading of the short tower.  The 4 element 20m M2 had dc grounding, but not 
enough elements.  I then went back to the LP to get some top-loading.

For small towers and beams it is easier to Omega match ( two capacitors). 
There is a little more loss when this configuration, but hey if it is all 
you can do then go for it.   It doesn't take much capacity for the shunt 
capacitor, sometimes as little as a few pF to 25-50 pF.

73 de w5jay/jay..


> Jim:
>
> Do you know where I can get one that goes up 90 feet?  I have not been 
> able
> to find one around here and several people need to use one to straighten
> their antennas out after the hurricane.  The only thing we have found is a
> crane with a hook and that is not what we need.
>
> I would be interested in how you loaded up your tower on 160 meters.  When 
> I
> build my new house I am planning on loading up one of my towers on 160. 
> One
> of the guys around here said that an 82 foot tower with beams on top would
> be too short to load up.  He uses a couple of Vacuum Variable Capacitors 
> to
> load up his tower.  He also said that you need to have insulators in the 
> guy
> wires about every 29 feet so they will not interfere with it.  I thing he
> said he had 64 radials buried in the yard and a lot of them go out into 
> the
> lake.  That is the problem with 160, all the radials.  An Inverted-L or a
> Double-L would work just about as well without the radials.  There are a 
> few
> folks down here running the Double-L with good success.  My Inverted-V at 
> 80
> feet just does not work well for DX and it picks up a lot of noise.  I am
> thinking about putting up one of the K9AY pendants for receiving at the 
> new
> place because I will not have room for a beverage.
>
> I have not worked VU7RG.  The pileups at night and on the weekends have 
> been
> crazy to say the least and I have been out of town a good bit.  I got back
> from Waco yesterday and I will be making a lot of trips out there as we 
> are
> opening a new hatchery and processing plant out there.  I was at Baylor
> yesterday morning meeting with some of the people in IT and looking at 
> their
> wiring infrastructure.  I saw a lot of ham tags in the faculty parking
> garage.  We had some sleet there yesterday morning.  I just cannot stay up
> late and work the next day to be able to work some of the good DX on 160
> meters.  I am going to work the CQ 160 Meter CW Contest Friday night. 
> Maybe
> I will catch some of you Okies on there.  I worked a lot of the guys in
> OKDXA this past weekend in the NAQP.  There are a lot of Okies that work
> SSB.  Listening to the reflector I thought it would have been a lost 
> cause,
> HiHi.  To me, I work them all, but I do prefer CW.
>
> 73,
> Alan, N5PA
>
>
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