The G3TPW CobWebb Antenna
Over the past 15 or 20 years I have heard many good reports from users of the G3TPW CobWebb antenna. I remember reading the review in Practical Wireless many years ago. There are a growing number of reviews of the antenna on the eham web site. In the last year I had discovered a web site which showed how to make a copy of the antenna. In act I bought a set of fiberglass fishing poles to have a go at building one but needless to to say I never got around to it. Mainly do to with not having a suitable piece of aluminum plate for the mounting plate.
So why would I need more that one antenna for HF ?.
Bits as they arriveWell I have an 80M doublet antenna at about 30ft with 450 ohm feeder into the shack and connected to a balanced ATU. It works very well on 80M through to 20M but as the frequency gets higher the matching becomes more difficult so an antenna for the higher HF bands would be very useful. I also want to keep the antennas low profile so an HF beam was out. I had thought of parallel aluminum dipoles. These would work well but at about 36ft for the 20m band it would be quite big.
The CobWebb is 8ft square and hence quite small and compact and so after many years of wanting to try this antenna I finally ordered it. I posted an order for the antenna on Monday the 1st of August 2005 and the antenna duly arrived on Thursday the 11th of August 2005. The photograph on the left shows how the antenna was packaged for dispatch. Its very well packaged with lots of bubble wrap to protect the antenna.
The instructions are clear and well written and Steve has added lots of hints and tips on how to assemble the antenna correctly. I test piece of fiberglass tubing is supplied. This lets you get used to putting screws into fiberglass with out wringing any of the antenna pieces.
The Antenna is supplied with all hardware require and mine had a few extra screws and cable ties. I assembled the antenna outside and used a Black&Decker WorkMate to hold the antenna.The top photo shown the antenna just before it was put unto the mast. I fitted a 2m mast into the WorkMate to mount the antenna on and to make adjustments. Total time to assemble and test the antenna was about 2 hours. This does not include reading the manual two or three times.
I made no adjustments to the resonant frequencies of the antenna. It was assembled, checked and put up on the mast at 30ft above ground. Resonance was within all the bands except for 12M and that was just outside the band. I am going to give it a try and then make adjustments once I get a feel for the antenna. So far it sounds very good and I will add a list of DX worked here soon. I also want to make some comparisons with the wire antenna to see how they compare. I also want to get a photo of the antenna on the mast up here soon.
73 es gud DX de GI4SJQ