[Elecraft] Connecting Transceivers in Vehicles - Change of Recommended Practice - OT

[David Ferrington, M0XDF]

Thought I'd pass this on, may not be so OT. I've seen many posts here on mobile installation and the use of 2 fuses, in fact I've posted on that and I use two fuses. The below came from a tutors reflector in the UK and affects our training.

Connecting Transceivers in Vehicles  - Change of Recommended Practice

Guidance for vehicle installation was originally contained in MPT1362 issued by the Radiocommunications Agency after consultation with industry. That role has now passed to the Federation of Communication Services and re-issued as the UK Code of Practice FCS1362.
http://www.fcs.org.uk/my%20files/fcs_pdfs/codesofpractice/08-05-12%20fcs%201362%20final.pdf.

There is a significant change in the guidance, section which will affect the UK Advanced examination and the UK Advanced course book.
The advice in MPT1362 and all copies of Advance! up to and including the 2009 reprint was to connect the transceiver directly to the vehicle battery with appropriate fuses in both the positive and negative leads. Often there is an incidental DC route from the vehicle chassis via the antenna mount, coaxial cable outer, rig and negative power lead to the battery terminal. Some vehicle load current will take that route and if the battery negative to chassis strap fails then all vehicle loads including starting current (100A plus) could. Clearly a fire risk especially for the super thin coax intended to fit round a door or boot seal.

New advice.
The new guidance is to connect the transceiver negative directly to the vehicle chassis and no fuse in the negative. (Assumes negative earth.) The positive lead should still be fused and connected to the battery or in accordance with the vehicle manufactures specific recommendation.
Remember that transceivers should be specified for vehicle use and the manufacturer’s guidance on RF power limits, antenna placement and DC supplies must be followed. Failure to do so might affect your insurance cover and questions on this point must be directed to your insurance provider.

73 de M0XDF, K3 #174
-- 
The bamboo that bends is stronger than the oak that resists. -Japanese proverb