So far from the brief trips I have made whilst mobile, the antennas seem to have made an incredible difference to the performance of GB3HS. Although the Diamond X-50 antennas may appear to have more gain on paper than the folded dipoles, the signal strength locally has increased dramatically as a result of more signal being radiated below the horizon as Clive describes.

The repeater's coverage is probably slightly reduced on the fringes due to the lower gain, however areas close in that were hard to reach such as along Hessle Foreshore, along the A63 between the Humber Bridge and Smith & Nephew and Brough are now seeing the benefits, and I am receiving solid S9 signals.

We look forward to receiving your signal reports.

73 de Andy

Is the Slim Jim a good antenna for repeater use? seems quite useful for simplex FM use.
cheap, robust, and claimed low angle radiation.
73s

The antennas we use are 1/2 wave folded dipoles fed at the centre and have the classic donut radiation pattern - giving some radiation at a downward angle from the hilltop the repeater is on. A slim jim is an end-fed 1/2 wave and is biased upwards, despite the 1/4 wave matching section, so probably not quite as good.

The antennas we use manufactured by Amphenol Jaybeam, and are meant for long term installations on commercial towers, or the classic guyed pole found on farms - they generally don't use dissimilar metals as it can cause intermodulation products. If you are careful will the mechanical construction, then a slim jim would be OK in that respect - we have found the usual white stick colinear antennas just can't stand up to the increased wind loading and fall apart after a couple of years.

Hope this helps...

Yes true quality pays for itself, unfortunately price does not always mean quality, commercial antennas are best for repeaters on insurance grounds as public safety is always a concern. 73s