This is an Icom IC-746 Pro. It uses a ccfl backlight for the LCD display. The regulator for the inverter circuit is a small surface mount PNP transistor, runs very hot, and has minimal heat sink area. This one failed, making the display nearly impossible to see. I replaced it with a much more robust part, and fitted it to the inside of the inverter enclosure for heat sinking. Here's a few pics, and a final test video is below...
I've been in Amateur Radio since 1974, and still find new and interesting things to do. I like to build, restore, and operate on the air. This blog has been running for many years, so be sure to check out "Jump to Posts on Specific Topics" in the RH column to drill down and find lots of stuff. Visit www.WB4IUY.net, email to wb4iuy@gmail.com, or leave comments here directly on my blogs.
Saturday, July 13, 2024
Midland 13-882C 23ch CB restoration...
Midland 13-882C. Here's another 23 Channel CB radio I saved from the land fill. :-) It looked, and was, rough. Dirty, non-functional, rusty from a damp basement, erratic controls, oxidized plastic chrome, etc. I love these projects!
VCO wouldn't lock, no matter what. I found the old wax poured on the VCO to be contaminated with moisture, much like the problem Kenwood had with some of their HF rigs in the past. I melted the wax out and all was well!
New lamps, cleaned controls, alignment, sanding, paint, and it turned out pretty good. While I was at it, I rewired the delta tune control to add a few channels to the PLL matrix. Here's a few pics...
NAF Headphones, WW2
A bit of WW2 history... Here's a few pictures of a NAF headphone assy from the Naval Aircraft Facility during WW2. Mfg by Best Mfg Co. with Shure Bro Anb-h-1 elements. They look uncomfortable. They've probably experienced a few things, too!
Kenwood TS-850S Backlight Repairs
6 Position HF Switchbox....
I had a need for a switchbox, to select between a number of low power radios... mostly boatanchors. Digging through the junkbox, I found a metal enclosure that was originally built as a multi-load t/r switch. I gutted it, made some changes, and whipped this up for $0. It now uses a non-grounding ceramic switch, and can select between 6 rigs, and has about 50dB of isolation on HF.



























































