Portable with the roach pole on 1.9 and 24 MHz

Today the weather was ideal for some /p over Hornchurch Country Park.

Equipment

85Ah Battery, Icom 7200, 18m Roach Pole, Inductor 340µH.

The roach pole provided 18m (60ft) of antenna, and when coupled with the inductor at 15m provided a match at 1830 kHz. The ATU was used to provide a match at 1910 kHz, the club top band frequency. It makes it all a bit critical having the inductor so high, but the big advantage is that the bottom 15.5 metres has a lot of current in it, leaving only the 2.5 metres above it at a high impedance, making a better radiator. Ground was provided by a chicken wire fence, which I have used many times before with good results.

Dave M0TAZ 18m roach pole

Below is a short video showing the antenna first on 24MHz where Dave is working Bahrain with the vertical set up close to a ⅝ wave, then afterwards, it’s fully extended with the loading coil 15.5 metres up, making it a loaded ¼ wave for 160m. The antenna was resonant at 1830kHz, a bit low, so the ATU was used. I calculated for 1900kHz, so I guess 70kHz off isn’t bad! It would be easy enough to fine tune it. Lovely day for it, a bit breezy towards the end though!

Updated: 13th September 2015 — 15:47

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© 2015 Dave, M0TAZ