Copasetic Flow

 Just a few notes on the varactor that's providing the FSK on the Rockmite and a few more notes on the FSK circut itself. This page will continue to evolve and is related to the slow moving project to try out teletype with Project TouCans . To communicate in most of the 20 meter RTTY band, the rig needs to have a 175 Hz FSK, rather than 500 to 700 Hz. I'm woroking on understanding the FSK circuit to see if it can be modified to give the desired shift. Short conjecture: I suspect/hope I can place a small variable capacitor around the varactor to bring the frequeqncy shift into the range that will work. The RockMite achieves frequency shift with its Colpitts oscilator via the following circuit from the manual and I'm just not sure how this works out. When Q2 closes, it looks like there should be a short to ground. The Zener, D5 with its 4.7 V reverse voltage, is immediately gone. Using the capacitance chart below, it looks like we gor from 100 pF from the varactor ot on the ...

 Can a RockMite send RTTY without a modification? Maybe. There are are two reasons it might not be able to. First, the keyer might not quite work the way I'd like for it to. What I need the keyer to do is to allow me to hold the key down in straight key mode while changing the FSK frequency of the rig by tapping the programming button. The second reason is that the frequency shift on RockMite's is between 500 and 700 Hz. Meanwhile, most rigs on the ham bands use a 45.5 baud rate with a 170 Hz separation. However, the German weather teletypes transmit at 50 baud with a separation fo 500 Hz, so there's a precedent for recievers that could decode RockMite RTTY if a RockMite could RTTY. The nice thing—the thing that got me thinking about teletype at all—is that RockMites have a built in, controllable FSK. Consequently, I asked ChatGPT to write microPython code to pull the FSK line on the RockMite. What I hadn't thought through was that KO6BTY, or I still needed to add a re...

When making our QSO skip maps one of the issues we encounter is that the lines from our station to the F2 layer don't always start right at the ground. This seems to be an artifact of CZML and the fact that the Earth is not a sphere, but rather an ellipsoid, and even then, there are all those hills and mountains. The initial QSOs can wind mapped as up coming from underground: or, they can wind up starting from above the surface of the Earth In any event, it's been necessary with each map to adjust the elevation height of our station. I've yet to find a parameter to set in a czml that makes the starting point always be on the ground. "clampToGround" works for polylines that are always on the ground, but not polylines whose next point has an altitude greater than zero as the ground station to F2 layer polylines do. I added a feature into the JavaScript mapping application this week that allows me to adjust the height of all of the QSO's starting points at...

 The Soldersmoke blog referenced a post about a really cool missile tracking helical antenna.  Soldersmoke reference to EI7GL's writeup of the antenna. The specificity of the plaque down to the Marker Number reminded that the gang, my partner, and I had visited the White Sands Missile Range outdoor missile museum back in 2017 . Glancing through my pictures to see if we'd taken a look at the antenna, I came across this doozy which had this plaque on display in front of it I'm just saying here: when you have to start out with the sentence, "Not a flying saucer" and then follow up later with "action was initiated to start the vehicle spinning for stability" and then offhandedly mention that the vehicle traveled at 1.2 times the speed of sound before firing an explosive charge at apogee... ahem... Not a flying saucer indeed, but you know, totally a flying saucer :) Here's the entire plaque text: " Balloon Launched Decelerator Test Vehicle Not a f...

 The TouCans keyer works much better than it ever has in the past, (apologies if you were on the receiving end of a key down lockup), and it's all due to connections I made while unschooling with the 14, 12, and 10 year old gang of kids here. This story starts when they were 9, 7, and 5 years-old, so strap in :) I've probably written about this before, but here's the rough chain of connections The, then, five year old, known as Tawnse here, and I attend a design exhibit at SFMOMA where She and I find a Foldscope , a simple origami-inspired microscope that's pretty fun, and pretty cheap Tawnse develops an interest in microscopy The gang and I join the San Francisco Microscopy Society The Society is working on archiving their old documents. Daize, (aka K06BTY), and I are working on a book about Mike Gladych where we've accumulated a lot of documents. We attend their archivist committee meeting. I read the list of committee members, and there's a name I recognize, ...

 I've read a little bit about 'local data' lately, and I've become fairly excited about the idea. Two of the features of the concept that I like are that your data should be your own, not stuck behind a corporations gated off wall on the internet and that you should have a copy of that data that lives on physical media within arms reach. I won't venture into the second one today except to say that with Google, in particular, somewhat constantly doing away with applications it becomes bored with and Amazon deciding it has and then has not rights to serve movies I 'purchased', having my data in a usable format and in arms reach physically makes more sense than I'd like for it to. Today, I'm going to talk about the first thing, being in control of your own data to use as you see fit. As someone who develops open source apps, there are benefits to everyone beside me holding on to their own data. The biggest one for me being that I don't have to figu...

 OK, so this is just kinda cool! Suppose you're operating near mountains and are curious if your QSOs are hopping over the mountains, or if they're knife edge diffracting after smacking right into the mountain. You'll need to know how high the F2 layer was between your station and the receiving station and you'll need to be able to visulaize the path with respect to the mountain. It's taken a while, but we have that now!  Thanks to the GloTEC data curtesy of the NOAA, we know the F2 heights all over the world at the time of each QSO. We can also map our QSOs on a Cesium map with toplogy. This allows us to start with maps like this: where I wondered on the day of the QSO if TouCans' signal would clear the high way embankment, and found out that yes, yes it did. Check out the interactive map below. It has all the QSOs loaded with their actual F2 skip heights.