Delorme PN-40 circuit board photo

[+Rotareneg]

I took apart my Delorme PN-40 GPS which I've grown to hate for various reasons, so here's what's inside: (to view full size, click on the images to go the the Flickr page and then right click on the photo and choose original)

 

 

 

 

Here's the RF front end:

 

 

Here's the surface mounted barometer:

[+user13371]

Nice pics. Which solder pad had the little sense wire from the bottom of the battery compartment?

 

Ad not to stir a war, but why had you come to hate your PN?

[+Rotareneg]

That sense wire is attached to a small board soldered directly to the battery and cable terminals on the back half of the case, which then connects to the main board through a small ribbon cable. The board had quite a bit of stuff on it, along with an aerogel supercapacitor, so I presume it peformed various power related functions.

 

Interestingly enough, there was a small disk glued onto the back of the case with a little hole under it. I can only assume it was supposed to be a vent hole similar to the ones Garmin uses, with a hydrophobic membrane over a hole to equalize pressure without letting water in. However, the hole either didn't connect to the outside, or had the most minute pin-hole opening imaginable as I couldn't see it until I used a syringe to force water at considerable pressure into it which seemed to force a still quite small pin-hole opening in the outside of the case. If you want to check your own unit, it's on the right edge of the cable mounting surface on the back, on the line separating the polished and matte plastic, about 7 mm from the plastic rail for the connector that projects up from the case.

 

As to why I didn't like the PN-40? I'd say the main reason was that I've had it freeze up too many times, sometimes requiring me to format the internal memory because a track log or something else got corrupted. Another big issue I had was with the cable: instead of using simple and reliable leaf spring contacts like on an old Garmin eTrex, they went with these horrible little spring-loaded pins which wore out and wouldn't reliably connect without having to wiggle the connector around. The display visibility, while acceptable with the user interface and vector maps, could be extremely dark and muddy with some raster images (aerial photos for example.) The X-Map software you have to use to create custom raster images (and which costs at least $100 beyond the purchase of the GPS itself) was astonishingly slow when viewing and converting images to their own proprietary format. You had no option but to use Delorme's maps as there are no free/open maps available like there are for Garmin units. A minor thing I didn't like was the way it always did some averaging of the reported position when the unit wasn't moving instead of showing the actual random drift; I'd rather there have been an option to turn that on or off.

 

I can't say current Garmin units are any better as I don't have any, but compared to my old 60Cx or even older eTrex Legend it just felt a bit unreliable and vaguely unpleasant to use.

Edited May 1, 2013 by Rotareneg

[MtnHermit]

As to why I didn't like the PN-40? I'd say the main reason was that I've had it freeze up too many times, sometimes requiring me to format the internal memory because a track log or something else got corrupted. Another big issue I had was with the cable: instead of using simple and reliable leaf spring contacts like on an old Garmin eTrex, they went with these horrible little spring-loaded pins which wore out and wouldn't reliably connect without having to wiggle the connector around. The display visibility, while acceptable with the user interface and vector maps, could be extremely dark and muddy with some raster images (aerial photos for example.) The X-Map software you have to use to create custom raster images (and which costs at least $100 beyond the purchase of the GPS itself) was astonishingly slow when viewing and converting images to their own proprietary format. You had no option but to use Delorme's maps as there are no free/open maps available like there are for Garmin units. A minor thing I didn't like was the way it always did some averaging of the reported position when the unit wasn't moving instead of showing the actual random drift; I'd rather there have been an option to turn that on or off.

 

I can't say current Garmin units are any better as I don't have any, but compared to my old 60Cx or even older eTrex Legend it just felt a bit unreliable and vaguely unpleasant to use.

Interesting. You clearly know you're why around electronics. Too bad inasmuch as DeLorme was the only viable competition for Garmin. My read of the tea leaves is that DeLorme is phasing out of the handheld business.

 

For me maps are the only reason to own a GPS and they keep getting better, much better, more current, than paper.

 

Thanks for the post.

[+user13371]

Ironically, DeLorme began primarily as a mapping provider. I wonder how much paper atlases still contribute to their bottom line?

Edited May 1, 2013 by user13371

[+Gitchee-Gummee]

It seems you may have one of the lemons that every manufacturer seems to put out occasionally. At least, that's the way I see it.

 

I, my brother, nephews (2), brother-in-law, a friend many states away all own 40's or 60's and love them. One was junk when purchased but Delorme promptly replaced it.

 

Lemons are a gremlin that has plagued manufacturers since the inception of mass production. A way around producing these anomalies hasn't yet been discovered. This phenomenon certainly is not limited to GPSr units.

 

Hope you have better luck with another unit, regardless of make.

Edited May 1, 2013 by Gitchee-Gummee