Category: Uncategorized

Loyal readers know (blog article) that recently I obtained a device that can carry out capacity testing on as many as four lithium batteries at a time.  How exactly does the device measure the capacity of the battery?  How does the device dissipate the heat during this testing?  This blog article discusses and answers this question.  (more…)

(Update:  I am delighted to report that third and fourth door prizes have been added for this meeting.)

(Update:  I am delighted to report that the upcoming meeting will proceed as planned, see blog article.)

I am working to try to set up an inaugural meeting of Summit County radio amateurs and friends of radio amateurs.

If all goes well, This inaugural meeting will be Wednesday, July 1, 2026 from 6PM to 8PM at the North Branch of the Summit County Library.  This is at 651 Center Circle, Silverthorne, CO 80498.  Please do not just show up for this meeting!  Please check back to make sure the meeting will be going forward.  Please drop me a note at carl at oppedahl dot com to let me know you plan to attend.

But please save the date.  And please post a comment below with your suggestions for the agenda.

Proposed agenda with other topics welcome:

• Put in your name for a door prize.  A Meshcore starter kit!  A study book for the Technician ham radio exam!  Take a door prize ticket for either or both of the door prizes.
• Introductions around the room.  Probably we will find that some attendees are more experienced in particular areas and might be willing to “elmer” some less experienced attendee who wants to learn about some particular area.
  • Brief break time during which some attendees “pair up” for elmering in future days.
• Live demonstrations of elmering:
  • Experienced hams helping a less experienced ham use a 2-meter repeater for the very first time.  I imagine we will use the WB0QMR repeater (146.7000 – and 107.2).  Demonstration of repeater etiquette.  (Less experienced ham might be yours truly.)
  • Experienced hams helping a less experienced ham set up a DMR hot spot and configure a DMR 2-meter handheld to use the hot spot.  (Less experienced ham might be yours truly.)
• Introduction to Meshcore, including repeaters and companion devices.  Presentations by volunteers who have set up Meshcore repeaters in Summit County.  Review of map of installed repeaters in Summit County.  Hands-on looking at actual repeater and companion-device hardware.  Demonstration of actual messaging.  Demonstration of remote management of a repeater.  Optional — discussion of possible next sites for repeaters.
• Drawings for door prizes.  Somebody will win the study book for the Technician ham radio exam.  Somebody will win the Meshcore starter kit.
• Possible next activities —  a VE exam session?  Pick an approximate date for a next meeting?

I was in Leadville yesterday.  I was not able to pick up any Meshcore devices there.

Do you know of Meshcore activity in Leadville?  Please post a comment below.

Today a new Meshcore repeater got installed near Cottonwood Creek.  Thanks to this repeater, for the first time there is full coverage everywhere in Summit Sky Ranch, Maryland Creek Ranch, and Sage Creek Canyon, shown in the photograph.  Other areas of enhancements to existing coverage are in Three Peaks and Ravens Nest.

The repeater is called CO-SUM-C08.

See if you can pick it up on your Meshcore companion device.  The guest telemetry password is “hello”.

How good are Harbor Breeze batteries?  (more…)

Title says it all.  It will be recalled that Meshcore firmware version 1.15.0 had been released on April 19, 2026.  Now on June 6, 2026, version 1.16.0 has been released, as you can read about in this Meshcore blog page.  (more…)

I spent several hours yesterday in Vail, Colorado.  During this time I tried again and again to reach a repeater in Vail.  I received no adverts from any Meshcore devices, and in particular received no adverts from any Meshcore repeaters.

As far as I was able to see, there is no Meshcore activity in Vail.

Are you aware of Meshcore activity in Vail?  Please post a comment below.

A few weeks ago I learned about, and got energetic about, the Harbor Breeze solar repeater hack.  I have by now constructed several Harbor Breeze (“HB”) repeaters using the RAK4631 WisBlock Kit (blog article) and several more using the Seeed Xiao nRF52840 & Wio-SX1262 Kit (blog article).  But I am in the northern hemisphere, and it has been above freezing this whole time.

I now realize I need to worry about the fact that Winter Is Coming.  It seems that almost everyone except me already knew that (a) it will supposedly ruin a lithium-ion battery if you try to charge it at a temperature that is below freezing, and (b) very few of the commonly used chips for charging control provide standalone protection against trying to charge when the temperature is below freezing.

In this blog article I try to set forth the nature and magnitude of the problem and possible workarounds. (more…)

In an earlier blog article I described my worry that one of my four Seed SenseCAP Solar Node P1-Pro repeaters (seen at right, at an elevation of around 10000 feet or around 3000 meters) might have power problems.  I worried that maybe the batteries were no good, or that the solar panel was weak, or that the charging controller was not doing its job right.  I had to hike up to the remote location of this repeater and swap it out with a spare.

I have now had an opportunity to do testing on the ailing repeater.  A first bit of good news is that with some simple charge-cycling, the repeater now has no difficulty charging fully.  And a second bit of good news, as I discuss here, I have learned that Seeed uses really good batteries in this repeater.  (more…)