Having just acquired a digital camera, I thought I'd post a few photos of the external battery arrangement I rigged up for my PM2s. If interested, take a look here.

I'm neither web designer nor photographer (and just learning my way around the new camera), but the photos and text will give those concerned about the limited battery life of the internal PM2 power supply an idea of what can easily be accomplished.

Jim,

I remember you were working on this project several months ago and I'm gald you were able to share the pictures with us. You did GOOD. Now, what do you think a "fair market value" would be for the external battery pack?

86 hours of use? That's great. How about running the L1/CORS experiment with the PM2's. You got the juice to handle the mega-vector/mega-session project.

J.D. Billings

I'll have to look into the cost matter and post an update to the web page.

As to the L1/CORS experiment, I thought it was focused upoon a network in the LA/OK/TX area. Does it make any sense to add a CA site?

Jim,

As far as my little world goes, you're correct. A vector between you and me would be a bit overly "optimistic". Deral has the idea, I think, that several different experiments around the country may take place on the same night. I would love to have seen this turn into a national one night vectoring session....but who's gonna process all that data. It would/could be an amazing project - all these L1 units scattered amongst all these fixed position CORS stations. I just happen to already have an idea of the processing demands using 8 hours of data and 5 CORS sites. Many of us (I think "many") are planning to have multiple units running for the all night session to solve first the individual unknowns by CORS, then check the vector(s) between the unknowns with the observation data and or conventional checks. Get someone well out of your normal L1 "comfort zone" range to cook a unit on a "known" point over night and run data tests. I'm interested to see what we can do with a combination of CORS and long distance "buddy system" in terms of densification.

We may actually just be playing, but we're working hard at it.

Okay, can someone reiterate the selected date and time for the experiment? Any L1 users in CA (preferably northern) who'd like to share data with me?

P.S. Rough cost of the external power setup is $100 per system. (Labor not included.)

Local Target sells a battery pack in camping supplies that has a nice handle, both AC and DC charging cables and cig lighter jack type outputs, nice handle and all set for around $30-$40. It is about 7 x 7 x 3 ins. It includes a light. I can't remember the brand, I haven't seen them elsewhere.

- jerry

Jim,

the date set for "Interstate ORGI" is this Saturday night/ Sunday morning. Actual plan is to collect 8+ hours of data between 0600 UTC and 1400 UTC on 02.034. When I did my first 3 test sessions I actually collected a half hour more, before and after the target times. The session time originally was picked to allow for the best possible ionospheric conditions for the greatest length of time (Central Time Zone).

I have little doubt the ProMark2, given sufficient battery life, will do extremely well.

Great work Jim and excellent photos :)

Thanks for the heads up Jerry. Was this the unit that you spoke about?

Free Enterprise at it's finest...Wish I was as handy (or not scared of opening the box)as you are...I tend to mess up changing light bulbs...

Kelly...The unit pictured is the one that I use to 'jump start' my instrument man on cold mornings! Works best when there is a little dew on the ground..

TM

I assembled the same basic setup as Jim and I found this for a power supply. Seems to work quite well and will power the PM2 for many hours (days?).

Had I known about the available 12v portable supplies before I set out to make my own, I probably would have at least tried one; it would have saved both time and money. Frankly, I'd just never seen one before.

The one redeeming feature of my considerably more expensive approach is that I know what's in the box, and am comfortable that it can handle the rigors of field work.

Your almost there Jim

Put the PM2 In the case and run the antenna cable out the side of the pelican case or put a antenna connector on the case wall. Pack the battery in foam this will help keep capacity on cold days.
There are some good smart charges for lead acid that will not over charge the batt and cause the batt to vent
I would go your route Jim but use NiMh batts from Geodimeter power pack pro. With the batt and PM2 in the pelican case for protection from cold and wet. Pack the PM 2 and Bat in foam and you could extent the temperature range of the batts and PM2 and have a nice case to carry it in. Hang your case of the legs and just flip open the case lid to read the PM2 display when required.


One more thing Geodimeters NiMh cells are smaller size wise than the panasonic SLA you are using about 3500 mah about 16.00 hrs+- and all PM2 and batt would fit in your pelican case or go with a smaller SLA batt


Pete

Modified By FS3 Pete on 1/31/2002 at 1:45 PM