Very timely discussion as I am installing my KX3 into a 2015 truck.
I already installed a new Alinco DR-735T. Temporarily using a dc accessory plug for power and not running low RF output as the dc plug wiring is not large enough for the current required for 50w (dc outlet is clearly provided for charging cell phones or other low current devices).
But I bought some No. 8awg wire to run from the battery to a power distribution connector (which I already installed). Per the w8ji article I should run the No. 8 negative wire to a chassis ground in proximity to the battery ground (but not directly to the battery neg terminal).
I can do that. However the DR-735T power cord has both pos and neg lead fuses. Should I eliminate the neg fuse for the radio? (and on all neg lines to each radio component I am installing?). I have a main fuse for the pos lead that will be connected at the battery, plus each radio item has individual fuses on pos leads rated for their current draw.
Equipment location is about 12 feet from the battery (crew cab pickup) so that is a lot chassis for current to flow thru, so I feel running a dedicated neg wire to the engine compartment chassis is better than a short ground wire to nearby chassis (which would have to be on exterior of the cab as there is no exposed metal in the interior). That would be subject to corrosion from exposure. Under hood chassis is better protected from direct exposure to the elements (I live in an area where road salt is applied in winter).
BTW I recall installing the trunk mount 50w and 100w VHF MOT radios that used the chassis ground wire. Also recall installs in 24v ground-start heavy equipment (D8's, frontloaders, and roadgraders). We installed high current steering diodes to prevent 24v flowing thru the radio ground.
I will be mounting the KX3 at the dash of my F250 Ford using a combination or RAM mounts and ProClip dash bracket. I will have photos and description on my website in a few days to show that. My KX3 has add on heat sink which makes the exterior dimension 3/4 inch higher, so the std RAM mount is not able to accommodate this. I am using some HB 1/8-inch thick aluminum tabs to extend the RAM mounting "fingers" which might be of interest to others with this predicament.
73, Ed - KL7UW ---------------- From: Fred Moore <[email protected]> To: [email protected] Subject: Re: [Elecraft] KX3 Vehicle mount Message-ID: <[email protected]> Content-Type: text/plain; charset=windows-1252 Brian, if you run the negative lead all the way to the battery (direct) fuse the lead close to the battery. If you run the negative lead to point that ends in a frame ground do not fuse the negative lead. This does not conflict with standard automotive manufacture recommendations. Also carefully read almost all manufactures installations it says run the leads to the battery, and they provide two fuses on in the positive and negative lead. I have not seen an installation manual in years that didn't say directly to the battery.. Tom W8JI has some good explanations on they why's and how this came to be http://www.w8ji.com/mobile_ground.htm Regards.. Fred 73, Ed - KL7UW http://www.kl7uw.com "Kits made by KL7UW" Dubus Mag business: [email protected] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
