Tricks of the trade?
I’ve started to wonder, in a way I haven’s since I was about ten, what does everybody else know that I don’t. For example, something everybody knows: If a number ends in zero or five, it can be divided by five.
Something I only learned this year: If the sum of the digits in a number is divisible by three, then so is that number. For example for the number 2,931 the digits 2+9+3+1=15, which is divisible by three, but so is the number 2931/3=977. Maybe this is useful only if you are trying to figure out ropes for guying masts, but I still hadn’t heard about it.
How many of these little tricks are there?
Another one that I learned recently (off the Internet, so beware) is a way to find a starting point for an L C pair for resonance on an amateur band.
For any band, set L in microhenries equal to the nominal wavelength of that band. (For 40m, start with 40 uH, for 30m start with 30uH for example.)
Then C in picofarads is L/10 times 3 (or C=L*0.3 if you have a calculator, but I find it is easier to multiply than divide) For example to find a resonant pair on 30m, L=30 uH, C=30/103 =3*3 = 9 pF.
Using this method gets you close enough that a variable capacitor, or a few turns on a toroid will get you to resonance. The reactance of each component is around 1.8k, so if you need something higher, make the inductor bigger and the capacitor smaller, L=60uH C=4.5pF, for example.
You can also reverse the positions of L and C (make C=30pF, L=9uH for 30m) and get a reactance of around 550 ohms each.
Nifty. Anybody got any other tricks I haven’t heard of yet?
In other news…
I was able to take in Craig’s presentation on W1AW at the October meeting. Well worth seeing. Bug him to get the presentation on line if you missed it.
I gather there is some discussion about whether or not to bother with the in-person part of hybrid meetings, given that there aren’t many of us who attend that way. There will be fewer of us, I expect, once snow arrives in force. So far, the physical meeting has consisted mostly of a bunch of us sitting around watching a remote presentation on a big screen, as opposed to being present at a meeting in front of us while others passively watch the goings on on their screens at home without much engagement.
Can a club keep going without actual meetings, or does it become just another video channel to watch? Time will tell, I suppose. The in-person things the club does (Hamfest, Field Day, etc.) seem to do well, but can an outfit that only does those sort of things find anyone to be on an executive among a membership who otherwise passively sits around watching the ‘toob?
Eventually we will find ourselves without anyone to organize the things the membership does respond to.
Usually at this point someone will ask “So what do you plan to do about it?” The answer is that I don’t know. We can’t be the only group that has had this happen, so what do they do? Am I reading the situation wrong because I don’t spend my day staring at screens? Ideas? Feedback? Crickets?
73
mk
VE3FFK
… looking at cloudy skies.
Last Updated on 2024-12-23 by AdminOARC