LA2YUA – RF and related projects

After some hard drive failures I decided to up my backup game, and ended up buying two LTO-5 tape drives.

Radio over Fiber is a well established concept by now, this is a look at a wide band multi-antenna receiver system with radio over fiber distribution.

This is a collection of what is required to put a HP Z420 and (probably) Z620 motherboard in a new case.

The Symmetricom X72 is a very compact high quality Rb oscillator, I bought a broken one hoping the physics package wasn't broken.

The C-MAC STP 2373LF is a 2x2x1" OCXO used in e.g. the Epsilon EC2S GPS clocks. Since a number of these clocks were broken in obvious or subtle ways, I decided to reuse the OCXO's and other useful components from these.

Continuing even further along the military radio thread, I previously discussed military handsets here.

In this post I will show how I built a basic interface-box/intercom for interfacing a generic military handset to mobile radios such as the Motorola GM360 and the Hytera MD785.

The Furuno GT-88 is a GNSS timing receiver intended for precision timekeeping. These are my impressions after some testing, but before I've tried to build a full reference clock system based on it.

The Meinberg PZF180PEX is a fairly uncommon sight in northern Europe. It is a PCIe radio clock receiver for the German DCF77 long wave time signal, made by German company Meinberg.

This is a cute little clock intended for OEM precision timing, let's look at how it's built.

After some time with my modified Comtac-a-like Sporttac setup, I found a good deal on a few proper noise reducing 150 Ω dynamic microphones. In order to use them, I had to modify my setup a bit.

This post details how to modify the band split for a Motorola GP2000 UHF portable radio.

The D-LI90 battery is a fairly standard DSLR battery used by Pentax/Ricoh for most of their medium to high end DSLRs from the last 10 years or so, including the K-7, 5, 3, and 1. Since I started using my 300 mm F/4 lens I've noticed that performance across my…

One of the issues with building an RF Over Fiber system is the lack of affordable transmitter solutions. While detectors are extremely cheap, the transmitters can cost hundreds of dollars on the used marked.

The (3M) Peltor SportTac is a common low cost hunting/general purpose medium protection (~26 dB) ear protector headset with hear-through amplifiers.

Token Ring is dead? Long live Token Ring!

I had bought an AAUI 10BASE2 transceiver, mainly to get the AAUI cable for use with another device.

Inside were no major surprises, but still hopefully interesting.

The Pro Logic Audio Card, sometimes known as the 442 Audio Card, is the default computer interface card to drive the previously discussed Pro Tools Audio Interface unit.

Some notes about the HyperDisk 40 pin IDE DOM SSD The Hyperdisk SSD is a solid state storage drive, intended for industrial uses. It's a very compact module that normally plugs directly onto the motherboards 40 pin IDE header (44 pin variants also exist). The module uses a small connector…

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.