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This series of posts explores¬† fundamental op-amp design issues; why in some projects tough problems never turn up, yet in others they create insurmountable obstacles. The simplest op-amp circuits or design requirements can keep a designer away from the non-ideal features of op-amps, but sooner or later, all those tables […]

Cooking with Op-Amps, part 1: Introduction & Basics.


208mm of RG-6/U makes a nice 4:1 Balun. 10
This post comes under the Sidetracks category because it isn’t strictly part of J-Tech’s business (we don’t sell antennas) but it is related to wireless design. There were two objectives to this exercise: 1) learn about the Yagi/Uda antenna from a practical standpoint; 2) get something for nothing. The “something” […]

Building a Yagi Antenna for UHF




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We recently had a little fun working with a Raspberry Pi module while developing a line of sensors. Like all things open-source, documentation can be a little sparse, out of sync, inconsistent, and difficult to follow; it’s often organized as a reference as opposed to a lesson. Learning which documentation […]

Raspberry Pi – Python V3 I2C Support


An error message is emanating from our beloved Racal Dana 1992 Frequency Counter. It’s a classic but useful piece of test equipment, and we’d hate to see it go. Poring over the service manual, the timing error correction hybrid (TEC) is supposed to have a stop count of 800 +/-220; […]

Racal Dana 1992 Repair



how much eye candy can a post about putting dos on a usb stick require?
There’s a lot of old hardware operating out there, and many a test/interface suite still exists in old-school DOS. Moving these antique applications into a modern computing environment with all the extensibility and reusability we’ve come to know and love requires being able to at least see the old application […]

FreeDOS on a Stick