Selected Diversions

Several diversions are listed below including popular primers Dr. McCorquodale has written on vacuum tube audio.

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Introduction to Vacuum Tube Audio Electronics and Simulation

[HTML] Introduction to Vacuum Tube Audio Electronics
The basic principles of vacuum tube device operation are presented including the functional properties of common device topologies. This background is leveraged to casually analyze gain stages that are typically found in vacuum tube audio equipment. The summary is intended to prepare the reader for basic design and analysis of amplifier stages.

[HTML] Vacuum Tube Preamplifier Analysis and SPICE Simulation
A common cathode vacuum tube preamplifier stage is analyzed and simulated. The concept of a linear small-signal AC model for the vacuum tube triode is presented and employed for circuit analysis. Analytical calculations for preamplifier gain and bandwidth are derived and compared to simulation results in the spice3f5 environment where good agreement between the two is shown.

Amateur Radio (KD9QZS—formerly KF6OYZ)

[HTML] The external link here is my current FCC/ULS registration. I used to be registered under KF6OYZ in CA, but that license expired and I renewed it recently in Chicago. I use a Yaesu FT-60R Dual Band Handheld 5W VHF/UHF Amateur Radio Transceiver in the South Loop of Chicago. There is a shitty multi-path effect from my high-rise and others, but such is urban living. It gets decent range for a handheld, but doesn't make it to Europe on ionospheric propagation in the HF band (which is disappointing and isn't supported anyway). Short wave definitely propagates further. Yet I like the PTT (push to talk) accessory—I highly recommend this. I normally listen to my local Chicago Police precinct, which is just a bunch of shootings and murders. That aside, you can reach me on FCC Licensed Technician channels including CW or Morse Code—which I still know. Otherwise I'm on VHF/UHF bands (10m and 2m bands).
I've been debating taking the next level FCC/ARRL test for a General License, but I don't see much of a purpose. I've also considered registering for ARES and RACES (these are the two primary volunteer and amateur orgs for emergency services). Any advice on this effort is appreciated.
Apart from that, I own Midland 50 Channel Waterproof GMRS Two-Way Radio which is a Long Range Walkie Talkie with 142 Privacy Codes, SOS Siren, and NOAA Weather Alerts and Weather Scanning. Obviously you cannot reach me there (unless you are with me or near me), but I use it for camping frequently. The range is about 2mi. It's nothing like the Yaesu.

PADI Diving

[HTML] The link here is just to the PADI site. They don't host a public database of certified divers, which is stupid. Diving is frankly scary as hell, at times. I've done wreck dives and shelf dives. The one I recall the most was in Turks and Caicos, You NEED to wear a dive watch. You can easily become disoriented and drop your depth quickly. For PADI certification, it's not and insiginficant effort and you need to understand your tank's O2 level and your depth which will dictate your need to for a underwater decompression stop to avoid decompression sickness (aka the benz). Actually the only dive that ever scared me was in Turks and Caicos, because it's about an 8,00ft shelf dive. You can become totally disoriented and you obviously need a decompression stop. That said, diving is awesome. The things you can see are unreal and beautiful.


[HTML] I was an elected District Councilman in the District of Southeast Detroit. This is another link were they don't record anything. Yet it was quite an experience. There are so many stories I can share about that.