Ted’s essays

2-way radio repeaters

I created a presentation for our local ham radio club to explain the environment our repeater engineer was dealing with. The problem many great sites have is that their prominence attracts multiple transmitters with each addition making it harder for the repeater to pick up the signals we want out of the electromagnetic flood. Thus the situation I describe with this Downing Mountain repeater is common to many. I called this “Tracking A Transmission”. We follow a signal from the operator’s mouth through his radio and up to the repeater overlooking Hamilton Montana. Once the repeater gets the information, it transmits it out from a large antenna with 50 watts of power pushing it as much as 50 miles away. […]

electricity, components & circuits

Chapter 3 in the Amateur Radio Relay League (ARRL) Ham Radio License Manual is the most challenging to most students. Remember that out of the 35 questions on your written exam, 26 correct answers is a passing score. You can afford to miss nine, or one out of every four and still earn your Technician’s License. You could miss, or even skip over every component and circuit question without failing your exam. Do not get all balled-up in this one chapter. On the other hand, it is cool, and even useful to understand a bit of this stuff. So let’s try to GET IT, without stress or strain. You likely already found my favorite online exam preparation tool HamStudy.org I […]

wave behavior

Whether it is a stone tossed into a glassy-smooth pond, sound waves coming out of a trombone or electro-magnetic waves enabling radios to communicate, the wave behaviors are direct relatives to the physicist. One such person built a model to demonstrate wave behavior then his employer, Bell Labs, produced a movie of it. I almost called it a video, but those were not yet invented in 1959 when this was produced. Last year I pounded enough correct answers into my head that I passed my Amateur Extra exam. My motivation was that I really wanted to UNDERSTAND radio much better. I did not clear that hurdle on pure expanded knowledge of radio, but I found several tools that helped. […]

Darby Dog Derby 2020

I led a team of ham radio operators who provided two-way radio communications throughout the two day event. It really was fun for all… the mushers, the comms guys and the visitors who came to watch the show. I mostly stay secluded in my comms truck shell, “The Beast” where my mobile radio has the speaker volume so I can hear radio traffic over the dog noise. I did step out to take a few photos and three short video clips that I share here. Darby Dog Derby Skijor 11 start from Ted Dunlap on Vimeo. Darby Dog Derby 8 Dog hookup part 1 from Ted Dunlap on Vimeo. Darby Dog Derby 8 Dog hookup part 2 from Ted Dunlap […]

comms plans for Darby Dog Derby

The 2020 Bitterroot dogsled race weekend is coming up. I have the two-way-radio support plan mapped out, radios programmed, testing complete, batteries all charged up … I think we are as ready as we can get. For more details about the weekend, the participants and the races, go to The Bitterroot Mushers website. Each year we learn more, adding refinements to patch holes as we find them. Ideally we have 8 checkpoints with a checkpoint worker and a radio operator at each. That’s a bit dreamy as the last couple years we are lucky to have one person serving both roles at each. Bitterroot Emergency Amateur Radio Services (BEARS), the comms team, recently changed affiliation to Corvallis American Legion […]

final day of registration for ham class is Friday

This a repeat of my previous announcement. There is one more day of online registration for Darby Adult Ed classes. We stand ONE STUDENT SHORT of having enough to make it happen. I am bringing another amateur radio operator licensing class to Darby, Montana via the Darby Adult Education program in its Spring 2020 schedule. I have not keept track, but think I have personally assisted 40 or 50 people to earning their FCC licenses through my study groups in the Darby library. The snide saying goes, “Those who CAN, DO. Those who cannot, TEACH”. I’m okay wearing that. Good instructors are as rare as good anything else. I did not choose this calling, blessing or curse. It chose me. […]

Ham license class begins February 1st

I am bringing another amateur radio operator licensing class to Darby, Montana via the Darby Adult Education program in its Spring 2020 schedule. I have not keept track, but think I have personally assisted 40 or 50 people to earning their FCC licenses through my study groups in the Darby library. The snide saying goes, “Those who CAN, DO. Those who cannot, TEACH”. I’m okay wearing that. Good instructors are as rare as good anything else. I did not choose this calling, blessing or curse. It chose me. Run with your talents. Every person who has come to all of the class sessions and studied two or more hours between sessions passed the FCC Technician License Exam at the end. […]

Darby Adult Ed calendar is up

I have contributed numerous classes to the community, most through the Darby Adult Education program in southwestern Montana. An interesting array of people share their skills and passions with others in this nice little community. This Spring Semester is no exception. We have many nice choices in front of us for new experiences, knowledge, training, friendships and fun. I am bringing my first-level Amateur Radio class back by popular demand. I must be nearing 50 people I have helped earn their FCC Technician or General Class licenses. My guarantee: If you attend every class and study a few hours a week, you will pass the FCC Technician Exam at the end regardless of your technical background or lack thereof. I […]

The Amateur’s Code

An anonymous gift through the Darby Library for me was a binder containing PREPAREDNESS COMMUNICATIONS written by David Pruett / KF7ETX. It covers Ham radios, non-Ham optons, communications plans, study and other resources. Some new, some refresher, all well organized. I was particularly taken with this cultural bit written by a licensed amateur radio operator ninety years ago. Modern hams would do well to pay attention. While much has changed, the desirable personal attributes have not. I typed it in as written. – Ted – P.S. The photo is from my archives. I have no idea who it is, but doubt it is Paul Segal. It simply represents what amateur radio stations used to look like. The Amateur’s Code by […]

letter to radio friends

Yeah, I’m kind-of busy like a one-armed-paper-hanger, but not THAT busy that I don’t intermittently attempt to get the code plug built into my (our) TYT VHF/UHFradios.  My latest attempt at using technology to pull an existing one out of another brand, make, model radio has not yet born fruit.  My repeated requests for a current list of repeaters, frequencies and PLs have also produced nothing… other than a curt “All Wrong” response to the old list I do have and submitted ‘for corrections’. The pair of Bitterroot repeater gods is in the middle of taking several repeaters down and installing new or reconfigured hardware. THAT changes the programming and their list. SO they don’t want to bother with a […]

Grubsteak

Also known as Downing Mountain, or the 146.720 North Repeater, this site presents extreme challenges to the engineers keeping it alive for amateur radio users. I put together a presentation for the local ham club, but the projection format washed out my drawings making them unusable for the back half of the room. I put them here for anyone who wants to see a pictoral representation of the challenges our tech team is dealing with. Paul’s White Paper covers the same turf from the technical side. Read it in .pdf form here: 72 repeater analysis Their relationship is that I used the data and analysis from his white paper to build my slides. My pictures provide the visuals while his […]

2-meter directional antenna for ten bucks

Two way radios, and particularly the little 5-watt Handheld Transceivers (also known as HTs or walkie-talkies) put their little bit of power in every direction. Yet we sometimes know exactly what direction we want to transmit and would prefer all the power go that way. A century ago two Japanese scholars created an antenna design to do exactly that. We call the design by one of their names, Yagi, but it seems the other, Uda, was the real inventor. Such is history. Following 100-years’-worth of radio technician footsteps, I have designed a simple hardware-store Yagi antenna to focus 147 MHz signals in a primary direction. I used some heavy copper grounding wire and a 4-foot piece of PVC pipe, […]