Ham Radio Performance Debug with Datasette

Had I set the power amplifying transistor's bias high enough, or did the radio always work this way with the amp? It's good to have data!

I've been collecting reverse beacon spots and QSO data since around the start of this year. The reverse beacon data is collected automatically, inspired by a productivity and documentation talk by Simon Willison.

Last night, rain got into the Project Toucans radio. It's not waterproof enough yet, I guess. Turns out there are whole issues in using Tuna and fruit cans as radio cases that I'd never thought through. The lid is corrugated making it difficult to seal holes against water. Anyway...

Earlier this evening, I had the radio/amplifier combination back up and running, but were they running well enough? Fortunately I had data for that. I queried the data using datasette. I asked about reverse beacon spots since the amplifier was added into the station mix a few days back:

select rowid, id, tx_lng, tx_lat, rx_lng, rx_lat, timestamp, strftime('%H:%M:%S',timestamp) as tod, dB, frequency, Spotter from rm_rnb_history_pres where "timestamp" > :p0 and tod > strftime('%H:%M:%S','00:01:01') and tod < strftime('%H:%M:%S','03:01:01') and dB < 99 order by dB desc

The 'dB < 99' clause removes QSOs (a ham radio abbreviation—Q code—for a two-way contact) which are all reported with a 3 digit RST—another abbreviation, this time meaning Readability (0-5), Strength (0-9), Tone (0-9). The query returned 219 rows of data. It was a little bit much for me to be able to get a handle on. In the meantime, while I was thinking through the data analysis I made two QSOs, one to KN6SSO in California with a received RST of 339 and one to N7SE in Colorado with RST equal to 539. I mean, two QSOs in one night is way above average for the Rockmite, but the reported signal strengths were comparatively small, 3 out of a possible 9. Whether or not the radio and amplifier were working as good as before the fix was still inconclusive.

I finally remembered that I had turned down the bias on the power transistor in the amplifier. That would indeed reduce signal strength, so I brought the radio down to turn the bias up on the amp. That netted me a report of a 10 dB from K3PA-1. That was pretty good, but was it as good as before? Then, it occurred to me, I could limit my search down to just K3PA-1 and find out.

Here are the results:

Ignoring the single exception in the first row, 10 dB at the time of night I was operating was a respectable result for the radio/amplifier pairing. The bias adjustment did the trick!

Just to make really sure, I also cohse VE6JY which had just in at 20 dB. The results

once again showed that while 20 dB wasn't the best signal that had ever come out of the Project TouCans rig with respect to VE6JY, it was solidly within the range of historical results! The fix had worked well enough!

Here's a map of this evening's spots and QSOs. The link will take you to an interactive map in Google Earth. Yellow markers with the letter 'R' represent reverse beacon spots. Blue circles with antenna symbols represent QSOs, including my first ever QSO to Stockton, CA!

The Valentine's Day Magnetic Monopole

There's an assymetry to the form of the two Maxwell's equations shown in picture 1. While the divergence of the electric field is proportional to the electric charge density at a given point, the divergence of the magnetic field is equal to zero. This is typically explained in the following way. While we know that electrons, the fundamental electric charge carriers exist, evidence seems to indicate that magnetic monopoles, the particles that would carry magnetic 'charge', either don't exist, or, the energies required to create them are so high that they are exceedingly rare. That doesn't stop us from looking for them though! Keeping with the theme of Fairbank[1] and his academic progeny over the semester break, today's post is about the discovery of a magnetic monopole candidate event by one of the Fairbank's graduate students, Blas Cabrera[2]. Cabrera was utilizing a loop type of magnetic monopole detector. Its operation is in concept very sim

Cool Math Tricks: Deriving the Divergence, (Del or Nabla) into New (Cylindrical) Coordinate Systems

Now available as a Kindle ebook for 99 cents ! Get a spiffy ebook, and fund more physics The following is a pretty lengthy procedure, but converting the divergence, (nabla, del) operator between coordinate systems comes up pretty often. While there are tables for converting between common coordinate systems , there seem to be fewer explanations of the procedure for deriving the conversion, so here goes! What do we actually want? To convert the Cartesian nabla to the nabla for another coordinate system, say… cylindrical coordinates. What we’ll need: 1. The Cartesian Nabla: 2. A set of equations relating the Cartesian coordinates to cylindrical coordinates: 3. A set of equations relating the Cartesian basis vectors to the basis vectors of the new coordinate system: How to do it: Use the chain rule for differentiation to convert the derivatives with respect to the Cartesian variables to derivatives with respect to the cylindrical variables. The chain

More Cowbell! Record Production using Google Forms and Charts

First, the what : This article shows how to embed a new Google Form into any web page. To demonstrate ths, a chart and form that allow blog readers to control the recording levels of each instrument in Blue Oyster Cult's "(Don't Fear) The Reaper" is used. HTML code from the Google version of the form included on this page is shown and the parts that need to be modified are highlighted. Next, the why : Google recently released an e-mail form feature that allows users of Google Documents to create an e-mail a form that automatically places each user's input into an associated spreadsheet. As it turns out, with a little bit of work, the forms that are created by Google Docs can be embedded into any web page. Now, The Goods: Click on the instrument you want turned up, click the submit button and then refresh the page. Through the magic of Google Forms as soon as you click on submit and refresh this web page, the data chart will update immediately. Turn up the:

Copasetic Flow

Search This Blog