80m full size 1/4 wave GPA

I wanted to work some more countries on 80m for DXCC and participate in a local 80m contest during autumn.

The problem with my other antenna (Butternut HF6V) was that it performed quite OK on 80m, but was much too narrow for participating in a contest (bandwith 15 kHz only, because very good grounding system with 96 radials).

So I decided to set up temporarily (during winter months) a full size GPA for 80m and check how well this would perform vs. the Butternut. I can report a very good performance on transmit for continental and transcontinental DX-ing. Moderate performance on short distance / NVIS (not the best 'local contest' antenna).

I have no beverage antenna to compare the noise/QRN level, but imagine it is moderate to high. On calm days about S7 to 9, on other days S9+10... Click on any picture below to load the high-resolution image.
 
  The 18m glassfibre pole from SPIDERBEAM - see http://www.spiderbeam.net (quality and top service by a real Ham!) The antenna itself is composed of 12m of heavy flexible insulated copper wire 4mm˛ section + 7m of same but 2,5 mm˛ on the top. This 19m wire is tightly wound around the pole (pitch about 1 turn per 2m). There is no top hat. SWR <1.3 from 3.6 to 3.8 Mhz. No variation to observe in function of ground humidity / rain etc.
  A closer look to the base, which is designed for temporary/portable use. I am using only 3 guy wires (heavy nylon ropes) about 8m from base. For permanent installation, I would recommend to use a second set at about 14m high.
  The 96 radials (each approx 10m long, and 12 of them are fitted at their end with a copper pipe 30cm long buried in soil. It is in fact the ground radial system of my Butternut GPA
  A closer look at the base loading coil. In fact, a coil is not really needed, but allows to finetune the GPA smoothly. The coil support is constructed as removable, I am thinking of swapping another coil for 160m operation. OK, I agree that the copper coil is a total overkill, but I had this material available for free ;o)
  Detail of coil mount. It is all made of PVC rainpipe and accessories available at any DIY shop.
  The antenna base. It is a piece of steel square profile 80x80mm and 600mm high where the glassfibre antenna base just nicely fits. The 'tripod' tubes are all of standard galvanised pipe.
  Counterweight at base is with concrete tiles of 300x300mm.
  Counterweight support frame construction. This can be removed from antenna base tripod for transport / storage...