The Trimble is indeed an early GPS unit, I first saw one during the first Gulf War when the Squadron were issued two of them. I'm not sure how often they appear for sale, or their going rate, as I had never looked for one before last Sunday.
Anyway, here are a few pics of mine. The silver bit you see poking out of the side is a co-ax connector for an external antenna, although the unit has it's own built in one. I wanted to show a pic of the screen display, but it ate all the batteries I had laying around whilst playing with it last night. A pic of the rear showing the battery pack which holds eight AA batteries, and can be removed and replaced with a power adaptor which allows you to run it from your vehicle electrics. I'm pretty chuffed that it came with the vehicle adaptor. I also received a users handbook with it. A look online showed that there are twenty-one versions of this type of Trimble, and this one is a TransPak (Spartan), Part No 14992-20, NSN 5825-01-364-6283. This unit is moulded in black with later models being moulded in green. Not too bad for £50 though me thinks.
I suppose I'd best keep an eye out for an external antenna and a vehicle mount for it now.
Regards,
