Highfields Amateur Radio Club
Technical Pages.
Mobile Installation:
Cautions and Warnings.
By Brian MW0GKX.
Warning Do NOT...
(When mounting the Radio / Accessories).
- ...use rubber bands, Velcro®, bungie cords, spring-loaded clamps or wedge trasceivers in place with pieces of wood, plastic etc. Any of these could give way in an accident making your radio a deadly missile!

- ...use an unsecured handheld transceiver, it too could become a deadly missile in an accident.
- ...obscure the drivers view of the road. A good rule of thumb is to keep equipment out of the line of sight of the driver as he/she looks through the swept area of the windscreen wipers from their normal driving position (the green area in the picture).
- ...fit anything in the deployment path of an air bag (SRS). These inflate at around 200 MPH and anything in their way is, quite literally, removed at high speed! (I have seen a photo of a mobile phone that was forced from its cradle by an air bag. It had fatally hit a rear seat passenger in the face!)
Warning Do NOT...
(For Power).
- ...use the accessory (cigar/cigarette lighter) socket for power, the wiring (especially in newer vehicles) would be running close to or at its limit and these sockets are renowned for 'letting go' of plugs that are a slack fit.
- ...fit fuses of a greater value than listed by the manufacturer of the radio equipment, or even use no fuse at all!
- ...splice into a power cable that is already fitted, the extra load could overload the vehicles wiring and cause a fire. Also there is the possibility of introducing interference to the radio from the vehicle (or even to vehicle from the radio).
Warning Do NOT...
(General).
- ...route cables near sources of heat. Plastic insulation melts and this can cause a short.
- ...have dangling coax cables, mic cords, power cables etc. They can and do get tangled up, especially with any controls they are near.
Caution...
(When mounting the Radio / Accessories).
- ...vent mounts are fairly popular but, I think, a bit flimsy. Will they hold up in an accident? Will the vent slats that they hold on to be strong enough to hold that radio head? Will the equipment overheat in winter when the heating is on? Only you can decide!
- ...suction mounts can 'fall off' the windscreen, especially in hot weather (I have experienced this with my SatNav mount, it doesn't seem happen in winter so much). If you are moving at the time (usually a 'bump' is the final nudge it needs to let go) then the mount and its contents will fall / roll about loose.
- ...disconnect the battery NEGATIVE before beginning work on fitting a transceiver. If working in the area of an airbag wait at least 5 minutes after disconnecting the battery before beginning.
- ...fit a fuse to the negative power lead if it is connected direct to the battery, because if the vehicles ground cable from the battery fails your engine could try to pull starting current through the coax and radio power lead!
- ...use grommets over any exposed sharp edges and secure leads in place.
Caution...
(When operating mobile).
- ...in adverse weather conditions (ice, rain, hail, sleet, snow etc.) do you really need to let Charlie know what that idiot driver in front of you did? You really should be concentrating on avoiding said idiot or you are in danger of becoming one yourself!
- ...also in rain, if you think that a thunder storm is coming, remove the antenna. Better to get a bit wet than have a lightening stirke wreck the antenna, radio, interior of the vehicle etc. I have read that Charles Gyenes, owner of HiQ Antennas, has repaired dozens of antennas damaged by lightening; it is not a freak or rare occurrence!