My new Sharman Collinear Antenna
Today I erected my new Sharman Collinear Antenna – a Sharman 2m/70cm Dual Band Base Antenna. My previous collinear antenna had been a Diamond V2000, but it had reached the end of its life. The joints between the fibreglass tube and the chromium-plated had degraded on the Diamond V2000 and it literally fell apart in my hands as I took it down. In addition, the long metal element of the counterpoise for the 6-meter band had also come loose from the tube containing the loading coil. The Diamond V2000 antenna was about nine years old and didn’t owe me anything and I had temporarily replaced it with a south-facing Diamond A430S10R2 10 element yagi for the 70-centimeter band. However, I missed being able to join in nets on the 2-meter band. Initially, the Diamond V2000 and subsequently the Diamond A430S10R2 had each in turn been mounted on top of a 30-foot pole consisting of six supposedly NATO fibreglass tent poles bought from the Newark national hamfest and stacked one on top of another. The coating on the fibreglass poles had degraded in the UV from the sun and therefore also needed replacing. So I ordered the Sharman Collinear Antenna and 8-foot long medium-duty mast from moonrakeronline.com on Friday 17th June 2022 and it arrived by courier on Monday 20th June 2022.
Today’s weather forecast predicted the sunniest day of the year so far – an ideal opportunity to get the ladders out and take down the yagi and poles – which proved to be easier than I anticipated and completed in minutes.
A post on a blog site recommended wrapping the coax in electrical insulation tape to protect it from abrasion against the bottom edge of the weather shield below the Sharman X-30, and I followed the recommendation. I could not find any recommendation online to insert a single loop in the coax below the antenna to act as a choke, which is usually recommended for the Diamond V2000, but I did that anyway as a precaution.
The job was completed within about two hours after I had started. All that remained was to check the antenna SWR at the other end of my Westflex 103 feeder. My NanoVNA-H4 gave SWR readings below 1.2 in the FM sections of the 2-meter band and 70-centimeter bands – success!
This evening I was able to take part in the Gilmore Radio Club net on the 2-meter band. I could hear all the net participants and could be clearly heard by them, thanks to my new Sharman Collinear Antenna.
I would like to clearly state that there is no connection between this blog and the Moonraker company and that I paid for my Sharman X-30 and mast, including courier delivery.