Date 25/01/02

Table 4.2 on page 38. The title is incorrect and should read "Data for HF mobile whips by G8ENN".

One of the major problems of mobile operation with a modern vehicle is possible mutual interference between  amateur radio equipment and vehicle electronic systems. Since writing the mobile book  my Shogun (which featured in some of the illustrations) died of old age and was replaced with a more modern vehicle (Renault Laguna estate) complete with modern electronic systems.  So far I have had no problems with the vehicle electronics when transmitting although there is some interference to the radio under certain conditions. More details to follow later.

Pat Hawker, writing in Radcom's Technical Topics, mentions European Commission (EC) Directive 95/54/EC. This states that no vehicle built after 10th October 2002 can be fitted with radio or electronic equipment unless it has an 'e' mark, not to be confused with a CE mark. The RA is currently unaware of any manufacturers who are making equipment to the 'e' standard, presumably because of the difficulty in specifying such equipment.

Don't panic, we have been down this route before - remember the fuss about amateur radio kits. I will give more details as they become available.

The image on the right shows field strength measurements being made at Amberley Industrial Museum. The mobile antenna is a Texas bug catcher mounted on the rear of the vehicle on a large mag-mount. Field strength measurements are done using a receiver with a small antenna and a switched attenuator.

The mobile setup and the receiver are about 40m apart for the field strength measurements. All this is part of another project being written up for 'The ARRL Antenna Compendium, Vol 7".