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Previously we looked at the inputs, what they look like inside the amplifier, and the differences between ideal and real behaviour. This time we look at what comes out the front end of the amplifier. When hooking up a source (power supply / battery / amplifier) to a load (appliance […]

Cooking with Op-Amps, part 3: Output Impedance.



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. 12
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