Home > Uncategorized > 30 Year Old Quad Reborn – Part 2

30 Year Old Quad Reborn – Part 2

More on the quad antenna project.

Today I completed the driven elements for 15m. 10m and 11 meters. While doing this, I made measurements for 2 elements on 2 meters just for fun. I found the spacing on a little close but decided to give it a go anyway. I added a reflector and driven element for 2 meters.  Element length on 2 meters is critical so I cut the elements as precisely as I could. Drilling the dowels in exactly the right place so that the wire joins was going to be a real challenge, so I drilled the dowels such that the circumference was just a bit small then shaped the wire into a small V shape at the join so that it fit at full length- see photo below. I am not sure what the effect of all the aluminium on the hub and boom will be- I suspect the 2 meter antenna will be a dud, but it will be fun to try.

Photo- 2 elements on 2 meters

Once I had all of the driven elements fitted, I cut some 75 ohm coax to length for each of the matching sections.  I used air dielectric W2082 coax which has a velocity factor of .95. I then soldered the matching sections to the quad loops and secured them. I only had one egg insulator, so for the others I  soldered the coax to the wire and cable-tied the braid down to the coax for security. I then wrapped each in Isobond self-amalgamating tape. Once this was completed, I fitted PL259′s to each matching section and connected my radio to check the VSWR.

Photo- 75 ohm matching sections connected. (15m, 11m, 10m)

Though the quad was standing on the ground, the VSWR on each band measured less than 1.2 : 1 first go.

I tuned the radio to the 15 m band, then aligned the quad on the ground towards Asia and listened in. It was amazing what signals I could pull out with just two elements on the ground. I then tried 10m and 11m with the same results. I wish to fit N type plugs to the 2 meter element, but had none, so that is tomorrow’s job. I don’t have a 2 meter rig yet, and I will probably have the quad in the air before I get one, so I hope the matching section works as well as the others.

Tomorrow I start on the directors.

Categories: Uncategorized
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  1. October 13, 2010 at 11:34 am

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