A Crummy Commercial

I saw this Youtube thumbnail and was "forced" to click because I had to know what the target was in Northeast Wisconsin / Upper Michigan: the orange blast above the E in NUKE and the T in TARGET was the one So I sat through 18+ minutes of somewhat lame content and of course it was never revealed what that orange fireball was targeting. I am such an idiot - of course they don't know how to pronounce: Minot - AI don't care, folks, can't get AI to care :) Best Regards, Chuck, WB9KZY http://wb9kzy.com/ham.htm

After learning that Bob Hamel had died: https://wb9kzy.blogspot.com/2025/01/another-one-of-my-elmers-has-died.html I started thinking about ham radio and Field Day which I associate with Bob and the rest of the Glen Gates Gang ( Mr. Gates was our physics teacher at Nicolet High School): http://wb9kzy.com/ggg.htm One thing about the way the Glen Gates Gang operated on Field Day was that we were expected to spend the whole event on site which was well over 24 hours.  So normally I'd bring a sleeping bag, a tent, lots of beverages and all the other stuff that might be needed on a mini-camping trip.  I usually ate sandwiches and always would get what we called:  egg bread but today is referred to as challah or maybe brioche ?  As I recall we used to get Heinemann's egg bread, good stuff.   Anyway, thinking of egg bread made me want some - I've never seen it for sale at Mann's here on the island.  So I decided to make some using this recipe by a friend's Dad: ht...

Somewhere I had a spreadsheet to de-compile and design active bandpass filters.  I can't find it right now so took a look on the internet for online filter calculators, the first two in the search results were: for de-compiling an existing filter design:  http://sim.okawa-denshi.jp/en/OPttool.php for designing a new filter:  https://www.ee-diary.com/2021/11/how-to-design-multiple-feedback-band.html So I took a look at the 4 stages of bandpass filters mentioned in the low-IF blog post: https://wb9kzy.blogspot.com/2025/01/low-if.html W6IOJ mentions in the article that there are four identical stages which are tuned in pairs to two different frequencies.  But the gains will also vary as there are 3 different values for R1 (the resistor at the input) 47k ohms (twice), 33k ohms and 22k ohms.  Using the first site here are the results: W6IOJ says that there is unity gain between the audio input and output so those three different R1 values change the gain so that the ...

Using the "right side" of this circuit: https://wb9kzy.blogspot.com/2025/01/a-two-transistor-sine-wave-oscillator.html  I tried a single section bandpass filter: The values are from a design I had used previously with a four section opamp filter.  I had raised the cap values and lowered the resistor values to minimize noise.  The gain and Q are both low as that's the standard rule of thumb in ham radio.  I did notice a lot of interaction between the filter and the oscillator (600 Hz was the lowest frequency with the filter while before it would oscillate as low as 482 Hz).  A higher impedance buffer is called for here ?  But the circuit does seem to filter, the waveform looks less bumpy :) top: 2 transistor oscillator, bottom: single section filter - the filter circuit does invert it *looks* like a sin function to me :) This was a quick try of a single section on a solderless breadboard - I may try a 4 section filter (the usual configuration for this type ...

I received this in an email today: I just had purchased 10 of these BF256B JFETs recently, in fact I haven't gotten them yet, hopefully they will arrive this week.  This part is one of the last RF JFETs available in the TO-92 through hole package.  The J310 was always the preferred JFET but those have not been available from distributors in maybe a decade or more.  A surface mount version of the J310 is available but a lot of folks are skittish about soldering an SOT-23 three legged part. So time to fool with the BF256B and see if maybe there is a kit that might use them - if so, I will have to get on the stick and do a last time buy, End of Life is less than 1 year away !  Probably should expedite this before the tariff increases beyond the current 10 percent, too ! Best Regards, Chuck, WB9KZY http://wb9kzy.com/ham.htm

A couple of shots of Bob Hamel W9MO and before that, WB9AMC on Field Day: Bob operating phone on Field Day Bob operating the natural power station on Field Day (a hand cranked generator on the wall of the Evan's barn was to the left, out of frame) obits: https://www.jsonline.com/obituaries/pwix1053199 https://www.feerickfuneralhome.com/obituary/robert-hamel I remember the next summer after the Novice Quartet had been licensed: https://wb9kzy.blogspot.com/2022/05/the-novice-quartet.html Bob Hamel and Morrie Hornik (WB9JHW) had another set of weekly classes to get us up to speed for a General class license: code, theory and regulations.  The Hamel family was nice enough to allow us to inhabit their basement (where Bob and his Dad had their radio shack) those summer evenings.  And eventually that fall I went down to the Federal Building in Milwaukee and got my General.  If only they had followed with an Extra class ! (I was never a self directed learner  :) It all remin...

From yesterdays blog: https://wb9kzy.blogspot.com/2025/01/a-two-transistor-sine-wave-oscillator.html I retried keying the oscillator using the same trick I used before for the Wien Bridge oscillator: https://wb9kzy.blogspot.com/2022/02/wien-bridge-audio-oscillator-keying_27.html I shorted out the back-to-back diodes using a normally ON 2n7000 MOSFET: With the key up the gate of the 2n7000 is pulled high by the 4.7k ohm resistor to the positive power supply which turns the MOSFET ON and the oscillator OFF.  Key down then shorts the gate to ground turning the 2n7000 OFF and turning the 2 transistor oscillator ON.  It sounds pretty good ! roughly 7 mS ramp up/down times The CPO circuit uses about 1 mA key up and 3 mA key down at a 9 volt supply, 628 Hz. The circuit can be varied from 482 Hz (1250 mV p-p): to 1092 Hz (600 mV p-p): but I usually go with 600 Hz (1200 mV p-p): Very pleased with the result, was going to report it on the EDN site but it insists that my password is inco...