I've got a new car, a BMW 325 convertible (well, I've had it for about 9 months now) and am finally getting the mobile rig into it. The old mobile rig was in a Passat and I talk abou that here. After thrashing around trying to figure out how to shoehorn the old radio into the new car and have it look half way decent AND keep the passenger seat available, I decided to get a new radio, which simplifies things a lot.
I have the Icom IC-7000, which has a separatable faceplate, so the radio goes in the trunk (probably where the CD-changer would normally go) and the faceplate goes in the front, in front of the sunglasses drawer. The cable is in short supply, but should arrive "any day now".
There are some issues with the audio path, but my current plan is to take the audio output from the radio and feed it into the auxiliary input of the stereo (where the changer would normally feed in). Ooooh, some day, I could conceivably build something that intercepts the I-bus messages from the car and use it to control the radio.
While the radio always presents a bit of a packaging challenge, for HF mobile, it's the antenna that is hardest. On a convertible, you don't have a roof to work with, either as a ground plane, or as a place to put a luggage rack to which you can clamp an antenna.
In the Passat, I used a screwdriver antenna, which worked ok, but was very slow and tedious for band changes (or even frequency changes on 40). It also, absolutely, positively has to be in sight of the operator, which means in front. If there weren't a whole lot of places to mount it on the Passat, there's even fewer on the BMW. Also, I wanted to start fooling with ALE, which requires rapid retuning. So, it looks like an autotuner is the way to go.
In the past few years, the price on these has dropped. There are three major players in the autotuner business: SGC, LDG, and MFJ. SGC is the only one that is really catering to the mobile, end fed antenna market. I have a couple of LDG desktop tuners, and I'm happy with them, but the appeal of putting the tuner right at the feedpoint (the SGC paradigm) is very attractive, especially with a physically short antenna.
DC Power
DC power is always an issue, especially if you're going to run 100W output power. I also have an aversion to directly connecting to the vehicle battery, based on long experience with destroying batteries, unforeseen interactions, etc.
There's a nifty device called an echo-charger, from Northern Arizona Wind and Sun (actually, from the folks who make Heart Interface stuff for RVs and boats) that interconnects two 12V systems appropriately. I've ordered one, so we'll see how it works.
radio/mobile.htm - revised 1 Feb 2006 - Jim
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