|The design is from the W3FF website and can be downloaded here.
I used schedule 40 PVC pipe which measures 36.80mm O/D and 18.23MM I/D so is quite hefty. Do not skimp and use thinner walled pipe as it will be too flimsy.
The four coils shown cover 60m, 40m, 30m and 20m. The short is for 17m, 15m, 12m and 10m. The coils were wound with separated white bell wire. The ends were terminated with crimp ‘bullets’ for ease of connection/disconnection.
Initial tests have shown a good SWR on 40m and 20m. The next stage is to test on a 5m painter’s pole. More later…