Long range EDM

Long range meaning what?

Is the Kern Mekometer ME5000 on your list? Its range is 20 to 8000 meters.?ÿ

Most of these instruments havenƒ??t been manufactured since the 1990s (or earlier).?ÿ

I wonder how many government entities (state and federal) have these units wasting away in storage. Parts will probably be a problem. I thought the Tellurometer used vacuum tubes?

The NGS Instrumentation and Equipment Branch did develop a modified version of a commercial unit for its own use. See Charlie Gloverƒ??s post with some details about this and other aspects of 1970s surveying:

https://surveyorconnect.com/community/surveying-geomatics/big-red-1977-email-from-charlie-glover/ ?ÿ ?ÿ?ÿ

Good luck.?ÿ

Larry, got to ask...what are you working on now that requires a long range EDM? Or just messing around??ÿ

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I did a session at Trimble Dimensions on Tuesday...I had a picture in my presentation of a setup with 98 prisms...

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@john-hamilton?ÿ

Messing aroundƒ?? sort of. Cove Mtn pass to High Rock lookout, just south of Penmar park. 27.7 mi.

And from a dozen or more points across the valley.

Perhaps borrow one for several days???ÿ

@geeoddmike

Looking 30 mile range. Not commercial application. More of a return to old school.?ÿ

@larry-scott I don't have anything long range. I remember that the University of Pittsburgh, when I was there in 1980 or so, had a pair of electrotapes (microwave) that I think were given to them by the USACE. If I recall correctly these units had a voice capability over the microwave link because each end had to twist some dials, etc to get the correct distance. In 1986 or so I recovered a bunch of stations at the (proposed?ÿ then, now built) Stonewall Jackson Lake in WV that were all set using the electrotape. I GPS'd a few and computed a transformation to NAD83, it turns out they were fairly accurate. They were known to have some multipath problems that reduced the accuracy a bit.?ÿ?ÿ

As for some long distances, have you been up to station DAN (PID JW1512) on Dans Mountain in Allegany County? I think you can see pretty far from there.

FWIW, attached is a screen capture of the instructions for the use of Tellurometers. The manual itself is viewable on line at: https://www.google.com/books/edition/Tellurometer_Manual/XbwDZ-F4--kC?hl=en&gbpv=1&pg=PA17&printsec=frontcover

I used a more newer version that the manual describes. It was in the early 1970s and needed to measure beyond the range of our AGA Model 76. Never got the units (sent from storage) to work. I did get a headache listening to the various tones.

Perhaps the NGS I&M Branch Chief might have some contacts? His email is linked from this page: https://www.ngs.noaa.gov/INFO/OrgChart/NGSXDivXChart.pdf

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