Posted	Category
	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 audio...  READ MORE	ranickels 01/03/2021	Technical
	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 long been common prac...  READ MORE	ranickels 01/02/2021	Technical
	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 hereA pdf copy can be found below as well.   And now you know!...  READ MORE	ranickels 09/06/2020	Technical
	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/ucxInitially, 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 Leonard K...  READ MORE	ranickels 06/20/2020	Technical
	Class E Notes  There is a lot of misunderstanding about how a Class E amplifier works.     As the result of studying the literature and experimenting, I thought I'd share what I have learned over the past several years.   Below is an example of a test amplifier I used to optimize my 2 watt wspr transmitter boards.   It can be visualized as two circuits - the...  READ MORE	ranickels 06/06/2020	Technical
	Communications Associates Inc. SSB-125 marine radiotelephone What can I say, I like oddball radios!    There was already a different version of this CAI SSB-125 on my shelf but it had the remote control head, and this one was cheap, well under $100 including shipping, and I'm easily amused.   VIDEO DEMO HERECommunications Associates Inc. was a supplier of commercial, military, and marine radios based in Huntington Station, ...  READ MORE	ranickels 05/14/2020	Technical
	"B" Bench update  Like most of those reading this, I've upgraded and added to my test equipment inventory over the years, starting with the Heathkit VTVM I built when I was 15 or so.   There's no "right" piece of equipment, just personal preferences, and while I'd be the first to say my work habits are anything but "right" they are what they are, and I'm old enoug...  READ MORE	ranickels 02/03/2020	Technical
	The best cleaner/degreaser on the planet! I have no interest or affiliation with the company and discovered this product when I was looking for a good degreaser to clean my jukebox.   IT IS THE BEST!I like data, so I put confidence in the test results that can be viewed in the infographic below.I also like RESULTS and this stuff delivers.   Greasy dirt and grime are instantly dissolved and wipe away.   You ca...  READ MORE	ranickels 12/09/2019	Technical
	My experience with the Nouveau 75 Mini-review of the Nouveau 75 by W9RANI like it, warts and all!OK, maybe not quite that "mini"...here's a few of my impressions of this innovative kit from the 4 State QRP Group.I've been interested in amplitude modulation of a class E PA for some time and after Dave Cripe said to stay tuned for the next 4SQRP offering, I wasn't too surprised to see what it was, and bought on...  READ MORE	ranickels 11/12/2019	Technical
	Phasing SSB transmitter alignment - the easy way! Equipment manuals and handbooks of the 1950s and 60s were filled with complex oscilloscope screens and discussion of ripple and as a result proper alignment of a phasing rig eluded most hams.    But a clever New Zealand ham, Fred Johnson ZL2AMJ was able to see what everyone else had missed, and published a short note in the NZ ham magazine in 1972 that makes the process simple and r...  READ MORE	ranickels 07/20/2019	Technical