The W5RRR antennas are the flagship features of our club. Over the last year, we’ve been having issues with the D40 rotatable 40m dipole. Through the efforts of Ken K5RG, John AB5SS, and Tanner W9TWJ (supported the first repair effort), we’ve had 2 major repairs that are easily under-appreciated since there’s little fanfare for the work that goes into analysis, planning, procurements, execution, repair/re-repair and testing. The club is extremely lucky to have members who are dedicated to keep our station maintained and on-the-air.
A re-post from John AB5SS groups.io message on June 22, 2025.
First, many many thanks to Ken, K5RG, for climbing the 80′ tower TWICE (2 weekends in a row) to repair the D40. The first climb was cut short when thunderstorms moved into the area and we had to call it early. But second time’s a charm and we got it done today. Ground crew was myself and Terry Quick (thanks for coming out to help Terry!).
The Cushcraft D40 antenna has been not only repaired but improved. The old ‘ugly’ coax coil balun has been replaced with a DX Engineering Balun and is better than ever. The original design connected the coax directly to the antenna elements and the combination of the elements and repetitive stress from rotating the antenna led to broken connections (twice). The D40 has also been rotated 90 degrees so its radiation pattern is aligned with the TH7DX beam. SWR was measured and is lower than 2.5:1 across the 40m band with 7.15 MHz being the lowest of 1.35:1.
I also checked the other antennas SWR. TH7DX is doing great on all bands (10/15/20m). The 80m dipole is also good but please note that it is tuned for the SSB portion of the band, centered on 3.8 MHz and is below 3:1 from about 3.7-3.9 MHz. The R7 vertical is also good but note that on 40m, it is tuned for the SSB portion of the band. It’s below 2:1 on the rest of its bands (10/12/15/17/20/30m). With the D40 repaired, I plan to eventually retune the R7 to the CW/Digital portion of the band (well after Field Day).
So…the shack’s antennas are good to go for Field Day! Let’s have fun!
A few pics from the climbs are included below.
73 de John
AB5SS
