Magnetofunky - Transcripts

Clearing Brush

Episode Transcript. Length - 42:54

Image: A few of the parts for the Transistor Astable Multivibrator...

Magnetofunky No. 137. It's Sunday, September 1st, 2019.

[intro theme]

Hey. Larry here. This week I spent time clearing out the weeds to pick the best oscillator for the existing circuit without winding another inductor. The music - since I didn't spend any time curating - is more or less clearing out the pending pile of submissions, so no theme, just sounds...

[song] - 00:51

Ok, that was Nite Rite - Ash Code, an Italian Dark Wave band formed in 2014 in Napoli, from the 2016 album Posthuman, sent in by Metropolis Records.

This is a laid back (and often explicit - you bet your ass) weekly international podzine of extremely eclectic music and progressive politics, with a focus on energy independence for the 99%. My podpages are 1223studios.com/mfunky.h and facebook.com/1223Studios.

[Grid Theory] - 05:27

Tank Driver

In Grid Theory,

Picking up once again, right after I finished the show I went into oscillators, starting with the history...

The earliest of these types is the Armstrong oscillator (patented 1912) that used a small tickler coil to trigger the bigger inductor coil, meaning that while Sr. Benitez was developing his power plant system using a Model T Ford ignition coil and relay switch as the tank circuit and oscillator, over a dozen other engineers around the planet between 1912 and the mid-1920's were playing with LC tank circuits trying different ways to trigger oscillations, including the newly invented vacuum tubes. that's Hartley and Colpitt, most referenced online.

Anyway, I saw that going that way means having to use a tuned sine wave instead of a square wave to generate a spark gap. Luckily, I found the solution by going back to an analog version of the previous thing I tried - the 555 astable multivibrator, instead the original recipe invented in the 30's (probably post Benitez). This analog circuit became even more practical when transistors were invented in the 40's. Nowadays this astable uses transistors, resistors and capacitors and generates square waves, and that allows me to work out the duty cycle, which Nikola Tesla more or less said was more important than frequency when trying to create a disruptive discharge for a spark gap.

Also, as I was looking around for a simulation of the Colpitts oscillator on LTSpice or TINA-TI to see how it performs, I stumbled across a javascript applet created by a cat named Paul Falstad a few years ago. This browser-based applet is full of basic analog circuits pre-made and very low learning curve for editing and building. And yeah, both Hartley and Colpitt circuits are included. The cool thing is that it shows the positive and negative flow of current - there are surges, stalls and backflows. There's also an oscilloscope function. In less than a minute I could see how in the weeds I actually was on the oscillator circuits - and I could imagine a few engineers out there greatly enjoying my stumbling...

The browser applet is strictly for online use, but there's an earlier straight Java version for offline use, with manual, then I found a variation of Falstad's simulator caled CircuitMod that has new component models like logic circuits added, and playing with these two simulators for only a few minutes beat the hell out of both LTSpice and TINA-TI...

And you know, thinking of Benitez and whether he was still around in the 30's, I did a short search for biographical data on the Sr. and nothing's come up so far. When did he die, and was it natural causes? It doesn't help that 1910 - 1920 is when the Mexican Revolution happened, and I checked period yearbooks from the American Society of Civil Engineers, but I couldn't find him on the alphabetical or international membership lists for 1919, but not every yearbook is archived online, and so far nothing from Guadalajara either.

So anyway, for the past few days I concentrated on the analog astable, includingreading and watching videos like the 3 part series by a cat with the handle radiofun232, and going over and over, and over the math on how to pick the right transistors, resistors and capacitors to get the right 36KHz frequency to drive my 36KHz resonant coupled tank circuits. It took a day with the Win10 calculator in 'Scientific' mode and quite a few tutorials, but I worked out exactly the parts I needed for another shopping list-- [bell]

Ok, coming back with the store run results...

[Back To The Stage] - 11:37

Ok, Back to The Stage, continuing the straight set grab bag with There You Go, another effort by Atlanta-area artist K Gizzle, followed by Trouble - Art, a Chicago collective headed by Nick Swanson + Mitch Canning, then it's ROM, another tune by Oakland psychedelic folk outfit Saidtheanimals, AKA Zach Williams, and we wrap up with fear song - Kenny Hwang, an electronic rock singer songwriter producer from san francisco

[songs] - 12:17; 15:42; 20:04; 24:13





["Geeknotes"] - 28:04

Geeknotes: 09/04 - Writers for Migrant Justice, Green Apple Books on the Park, SF, 09/07 - Trans March Oakland, 09/07 - 20/20 Play at SF Fringe Festival, EXIT Theatre, SF...

Hey, Geeknotes!

It's Sunday afternoon, Labor Day weekend, big BBQ and beer weekend, unless you're in the path of Hurricane Dorian, like maybe Mar A Lago that some people are praying for - not me, cause he'll surely steal more Title X or military pension funds to rebuild his putrid ponderosa...

Anyway, as expected, after the G6+1 meetup the leader of the free world now is pretty much Emmanuel Macron, and meanwhile as Orange Queenie makes royal decrees to steal citizenship from children born abroad to military parents and lies about the domestic pain of his China trade war, we have another dickless red hat snowflake drive-by mass shooter in Texas; why is it that these neo-Nazi pussies never go to shoot up the headquarters of the Crips, the Bloods or the Latin Kings? They only go at innocent unarmed bystanders, knowing that when the cops come it'll be with happy meals drawn (and what you wanna bet how often one of the cops knows the asshole by name...)

Anyway I'm burning holiday time here, so let's run a few dates...

09/02 - Labor Day

09/04 - World Sexual Health Day

09/04 - Writers for Migrant Justice, 7:30 PM – 10 PM, Green Apple Books on the Park, 1231 9th Ave, SF

Hosted by Bay Area Writers Resist

Part of a nationwide campaign organized by writers Javier Zamora, Jan-Henry Gray, Anni Liu, and Christopher Soto, Writers for Migrant Justice is hosting a San Francisco reading featuring:

Chris Feliciano Arnold
Marcelo Hernandez Castillo
Ingrid Rojas Contreras
Tongo Eisen-Martin
Juliana Delgado Lopera
Maw Shein Win

09/05 - Int'l Day of Charity

09/07 - Trans March Oakland, 11:30 AM – 1:30 PM, Frank H Ogawa Plz, Oakland

Oakland is home to hundreds of transgender people specifically of color however, the city is overshadowed by San Francisco and its popularity around LGBT community based events.

This year Oakland will host its own trans march to create visibility and bring the community together in an attempt to have our own transgender movement and celebration.

We ask that you join us in marching from Oscar Grant Plaza to the lake area where we will join community on stage for a mini rally for Black Trans Lives and the Pride in the Park Ball.

09/07 - 20/20 Play at SF Fringe Festival, 6:30 PM – 7:30 PM, EXIT Theatre, 156 Eddy St, SF

It's 2020. The President has been re-elected, the climate is heating up, the economy in meltdown. In this satirical participatory performance, audience members choose the scenarios to stage: impeachment? a coup? a revolution? "20/20" asks what people power looks like in a time of vast uncertainty when even choosing to do nothing has consequences.

If you have promos, pluggers, gig info, an art opening, etc, send me an email. The address is mfunkyzine@gmail.com. And bands, artists and poets - download links, no attachments, please, and no promises...

[Grid Practice] - 33:22

Driver Parts

Ok, In Grid Practice,

My shopping list was geared to what I'm calling the deluxe version of the analog astable (or tank driver), that includes extra resistors from the voltage supply to the transistor collectors (in order to deliver a sharp square wave instead of a rounded leading edge), a pair of diodes to better channel the crossover flow to the transistor bases, a pair of resistors from the transistor emitter to ground to stop the base-emitter voltage from going too high, and finally adding a potentiometer from the supply voltage to the timing resistors to adjust the duty cycle of the frequency. For example, 36KHz frequency equals roughly 28 microseconds (according to my doing the math and confirming with a frequency period chart), so a 50% duty cycle is 14us on/14us off, and 25% duty cycle is 7us on/21us off, but using only the timing resistor and capacitor gives me a locked in 67% duty cycle, and the duty cycle research isn't defiitive; some engineers say you have to have a on cycle over 80% for good results, but Tesla and others in the 'free energy' world say an on cycle of 5, 10, 15% is better. I don't know, so a potentiometer will let me test that out, if what's on paper bears out in the actual circuit.

Anyway, on Thur. I visited Al Lasher's and picked up a few parts: for the timing set 9.1K Ohm resistors and 2.2nF caps and another mini-breadboard. I already have 1K Ohm collector resistors and 1.2K Ohm emitter resistors and a 1K potentiometer, plus my designated transistor, the 2N3904. I drew up a diagram of the tank driver circuit, but while I build it I'm using the Java circuit simulator to see what that looks like first, because if the emitter resistors don't work I might need to reduce the 12V input using a voltage divider, and it might be possible to get a stronger output by adding a 2N3055 power transistor in a Darlington setup. That would make an extra deluxe tank driver, but whatever it looks like it's gotta work through the simulator and the scientific calculator first...

[One More Tune] - 37:05

Ok, for this week's One More Tune, we close out with Perspektive, the title cut from the 2018 album by Italian Dark Wave band Ash Code, and BTW, they're on a mini-tour of the US playing today in Brooklyn @ Brooklyn Bazaar, and on Friday the 6th here in SF @ The Uptown...

[song] - 37:34

Well, OK.

[Closing] - 41:15

Hey, this show is a 1223studios joint.

I'm on Spotify, Tunein, Google Play, Stitcher, iTunes, Internet Archive, PlayerFM, Listen Notes, Podknife and Mixcloud. Show notes are on the podpages. Send email to mfunkyzine@gmail.com.

If you like the show, tell your friends, and, here's a nice fantasy - I'd love to see the Beltway corporate media refuse to report or repeat anything spewing from P-Grabby's mouth (or Twitter finger) unless he has the receipts to back it up. Yeah I know the last thing we'd ever see is a helicopter presser boycott, not while executive bullshit is so profitable. Meanwhile, I'm still waiting for Marxist economist Richard Wolff to answer my simple question: if all taxation is theft, why ISN'T all profit robbery?

Show themes "Rocket Power" & "Spy Glass" by NY musician and composer Kevin MacLeod. Some additional audio from freesound.org.

Next episode is set for Friday, Sept. 6th.

I'm Larry, trying hard to stay chill at my garrett in the Mission, and this is Magnetofunky, from San Francisco, where we go through, not into, the darkness.




© 1997 - 2018 Larry Winfield. Some Rights Reserved.
All other trademarks and copyrights are the property of their respective holders and authors.
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