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I spend most of the time on the low bands using CW. I particularly enjoy QRP DX on 160 on 5W and 1W on 30m bands. But the current challenge is 80m QRP DXCC and I need 20 entities.

I live in a small city lot and all of my antennas are on a single tower. This location is full of noise from all kinds of electronic appliances and high voltage lines. Very latest additions are big solar panels of neighbour houses very newly consructed which generate beautiful repetitive pattern in frequency domain that can be seen on P3 screen.

The antenna pix is replaced with the latest one; the system has been renewed with a thoroughly new 4 elment high band Yagi (18.1-21-24.8-28) and a 5 element 50MHz Yagi in addtion to the mid-band (7-10.1-14 as 2/3/3 element) Yagi restored from the damege by a typhoon last autmn and a mast mounted (1.8-1.9-3.5-3.7) vertical. All of these are made from fishing rods as always. There are lots of vacuum relays used for the band switching capabilities.

 

The upper Yagi is the mid-band that uses carbon fiber poles and the lower Yagi is the high band thatuses glass fiber poles. All of these fishing poles are "metallized" with adhesive aluminum tape and aluminum wires along wtih the poles so that they pretend to behave as true aluminum tube elements.

The vertical uses a 27ft long carbon fiber pole for the upper half element (12m long total to the top from the shoulder of the tower where this vertical is fed). The lower half uses a 20m long AC power code that descends from the shoulder of the tower towards to the roof of the house.

A pair of large loading coils are used for 160m resonace for both halves of the elements. I immensely enjoy Top Band dx on QRP with this vertical antenna. The very best 160m QRP DX was TF4M through the northpole auroral zone.

Seeyou on the air!

Best 73

de Shige JH1GNU / WG6B

++++++++++++++++++++++

I added aset of pictures taht show how I prepare such large dia meter coils.

Prepare pillars for the coil. My prefereed material is interior finish material. They do not have to be good insulator material such as Teflon but need to withstandexposure to UV.

The pitch is usuually 15mm or 3/5 ich for 3 to 4mm dia coil wire size. The pitch needs to wide enough to allow the use of wire clip for tapping.

Very loose hole size for the coil wire is the KEY of this construction. You see this later. I use usually 6.5mm dia drill bit for 3 to 4 mm wire.

Depending on the diameter of the coil you need use an adequate size can or whatever available. This can is physically reinforced.

Form a coil around the can. Thefinal coil diameter is +25% or so larger than the can diameter.

Now use your patience. The holes need to be much larger than coil material diameter. All of the stems must go together. You will appreciate the looseness of the holes.

The coil islike a soft-bodied creature....

 

Once the stems are reinforced wtih barsat the top and the bottom (for both pairs), it is provided witthe enough strength to support itself. The secret is the twist of the stems; the loose holes can hold the coil wire firmly.

I usually use 4 stems upto ca. 8 inch dia, and use 6 stems for ca. 12 inch dia.

The 160m coilis mounted onto a water pipe as you see in one of the earlier picutres, and this mounting provides the needed full strength as a coil assembly.

Enjoy!

 

 

 

 

 

 

 

34393 Last modified: 2012-07-25 03:45:44, 4888 bytes

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