Right after acquiring my PM2s I began fiddling with the notion of hooking it up to an external power source. I didn't want to modify any of the original hardware, so I bought a cradle and power cable for a Magellan 3xx receiver and adapted them to the PM2, but took a little longer getting around to setting up a power source.

Having recently completed that project (7ah sealed lead-acid battery in a Pelican case with a cigarette-lighter jack), I set out to see how long it would power the receiver. I started the test on Monday and finished it this morning. I had to swap receivers last night because the first was running low on RAM, but between the two of them I got a bit over 86 hours of continuous operation on a single charge.

I figure I'll still use the rechargeable NiMh AA cells for most jobs (I get about 6.5 hours out of them), but it's nice to know I can let one cook for a longer spell when necessary.

The mods to the Magellan hardware were more involved than I had originally hoped. It seems that the PM2 is about 3mm thicker at the top than the Magellans, so the clip arm wouldn't reach over the lip on the receiver. I had to file off the hook on the arm and replace it with a piece of 1/8" aluminum. (Question for you Ashtech guys: Is it possible to buy just the PM2 clip arm? My dealer says I have to buy the whole $150 PM2 cradle if I want another arm.) Also, the power contacts in the cable/receiver interface are a trifle too close to the bare antenna plug for my comfort, so I carefully added a little clearance with a die grinder. Other than those two modifications, it was plug-and-play.

Another question for Ashtech: Any idea when a factory-produced external power hookup will be available?

Thanks.