Articles
Technical information
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Elvis Mic fix
How'd it get that name? The photo pretty much says it all. .. One of mine had a problem - the guts could be heard rattling around loosely insdie. The "capsule" as it's called nowadays at least is held in position by three rubber "socks" that fit over metal tabs to provide acoustic isolation from the mounting provisions in the housings. No... READ MORE |
ranickels 01/13/2022 |
Technical |
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Where is the thing?
Looking for a tool? Important papers? Parts you just had your hands on minutes ago?  READ MORE
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ranickels 12/04/2021 |
Technical | |
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RANVerter Pi - SDR Upconverter
I became aware of a few hams playing with a thing designed to receive digital TV in Europe on your laptop - a little plug-in dongle that used an RTL-2832 IC and sold for $20 or so. Some clever fellows had determined that it could be put into "radio mode" in which it would generate an IQ stream over USB, and by writing to control registers in the tuner IC... READ MORE |
ranickels 06/13/2021 |
Technical |
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Restoring Aluminum Knobs
I've always thought that knurled aluminum knobs were a high-class option for radio gear, and while they are more durable than plastic they do accumulate tarnish, corrosion, and grunge from dirty fingers over the years and start to look poor. Fortunately it is easy to restore them to a new attractive appearance using a bead blaster. Mine is a Harbor Frei... READ MORE |
ranickels 04/29/2021 |
Technical |
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Replacing C-frame fans
It's not often that you can buy a replacement part for a vintage transmitter or amplifier off the shelf at the home improvement store, but this is one example. And since it's not a perfect drop-in replacement, here's now I adapted a new Broan-Nutone BP-27 bathroom-kitchen exhaust replacement fan to fit into a Johnson Desk Kilowatt. These small shaded-... READ MORE |
ranickels 04/23/2021 |
Technical |
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Restoring the B&W 850 Plate Inductor
The B&W 850 is a kilowatt-rated tank assembly that was used in the company's linear amplifiers and sold as a component for many years. Unfortunately most of the plastics available were not capable of surviving for 50-70 years and thus have deteriorated to the point they no longer support the coil turns properly and must be repaired. Here's a typical example fr... READ MORE |
ranickels 02/28/2021 |
Technical |
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AN/GRC-9 Bias Battery replacement
The Korean-war vintage AN/GRC-9 is one of the most useful and fun military field radios for ham use, as with AM and CW modes and 2-12 MHz coverage and a VFO it's all ready to go on several ham bands. The battery tube superhet receiver is also power-friendly and sensitive and stable enough to copy CW and SSB but has one annoying flaw - the 4 volt bias battery used by the aud... READ MORE |
ranickels 01/03/2021 |
Technical | |
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Beware of the LED Noisemaker!
Halogen type MR-16 lamps are commonly used in track lights and other spot lighting applications so what would be cooler than to drop in LED replacements! A lot, as it turns out. The LED replacements are HORRIBLE RFI emitters that totally trashed several ham bands when I unknowingly installed them. Halogen spot lights are 12 volt devices so it's lon... READ MORE |
ranickels 01/02/2021 |
Technical |
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why 50 ohms?
Why do we use 50 ohm cables? If you're like most hams the answer is: "I dunno!" In fact, it's a compromise (like most things in life) - between lowest loss when handling power and voltage breakdown, as Belden engineer Steve Lampen explains here A pdf copy can be found below as well. And now you know! ... READ MORE |
ranickels 09/06/2020 |
Technical |
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Bias control of Class E amplfiers
Micro SDR innovator Guido PE1NNZ has implemented polar modulation using an Arduino MCU and a class E PA. For more informartion on this fascinating project, join the discussion group at https://groups.io/g/ucx Initially, Guido's design implemented the polar or EER modulation scheme using modifications to the QCX CW transceiver hardware in the traditional way as described by... READ MORE |
ranickels 06/20/2020 |
Technical |
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