LA2YUA – RF and related projects

The Apple Ethernet NB Card is high end a NuBus Ethernet card, with the A/ROSE 68k coprocessor system included to offload certain processing tasks from the main CPU. Unfortunately, the card is cursed with the spectre of libertarianism. The v1.0 ROM dump is here: 341-0246 ROM. The ROM is a 27C1024,…

Some info on the miroGraph Chroma v3.3a NuBus video adapter.

In this article I'll take a look at the Digidesign Quad Audio Interface, also known as the Four-By-Four.

I dug out the old Mac IIfx from storage and had some fun getting A/UX running on it. I had some issues, so I decided to document them and collect some links etc.

Some viewers may have noted some 7-segment clocks in the background of some pictures in prior entries. I decided to update this system for the 2020 holiday season, and built 10 new clocks to replace 3 old ones.

This article is about modifying the HP 3456A voltmeter for 50 Hz operation.

I bought a used Icron USB Ranger 2212, and took a look at how they implemented the Cat5 extender.

In this article I'll briefly talk about my newest Mini-Whip antenna project, designed primarily to cover the lower bands.

Around the same time that I bought the USB 2.0 extender featured previously I bought some cheap remote units for the 3022 USB 3.0 (5 Gbit⁄s) system.

My thought was that maybe these were identical like the USB 2.0 extender.

From the looks of it I was wrong there and will need to find a LEX to use it, but it was still interesting.

I bought an Icron USB fiber optic extender, and had a look inside.

A collection of various info and thoughts about the Orion radio system, also sold under GE and M/Acom brandings.

Quick post with some information on MX1000/2000 programming that I wasn't easily able to find myself.

I bought some more 58534A-H01 receivers and found that these receivers were of the older type I had seen low resolution pictures of before.

On a whim I bought some pole mount GPS receivers. 

Being unable to find any real details on what's inside I mostly bought them blind, so I took some photos of the insides to help others out.

I bought a chinese made 3-cavity bandpass filter and decided to measure it and compare it to some home-made modified duplexer filters.

Updated: VHF information below

The Spectracom Epsilon Clock EC2S and similar devices are fairly high end GPS clocks/timing receivers.

I've spent a few days with one and I wrote a utility to program the device that is available for download.

A Procom VHF cavity band-pass filter was donated to the shack, and some work was done to retune it to 145 MHz.

I bought some Ascom SE-140s and figured out how to program them without buying a 386 computer and floppy disks.

I picked up a 18 year MiniDisc recorder and restored it a bit, and added some optical I/O to it.

I bricked my DCX2496 while updating the firmware, but I got it back.

I modified my IC-775DSP with backlighting and thought you might want to as well.

I looked in to modifying the IC-V200T for use with modern repeaters with 2.5 kHz deviation.

I looked in to modifying the IC-H16T for use with modern repeaters with 2.5 kHz deviation.

In this article I desribe how you can upgrade your H16T to use the Super-150 custom firmware developed for Icom V200T LMR radios. Be warned that some hardware modding and EPROM programming is required.

I've designed a 3D printable solution for rack mounting Lucent RFTG-u receivers on cheap 2U shelves.