I haven’t had time to update the blog because I’ve been busy designing a new headphone amplifier. There’s been a lot of development when it comes to operational amplifiers and I was curious about how well I can get an amplifier to measure using the latest technology. The op amp I’m using still hasn’t got a development board, so I make one myself. The op amps are 5x5mm in PVQFN-20, so you need to use an SMD soldering gun or oven to be able to solder them. I simulated the circuit with both LTSpice and TINA90, but left biasing resistors and some other stuff in good old fashion though-hole components for easy testing.
I wanted to get a distribution amplifier for my 10 MHz lab reference signal from my GPSDO to feed my equipment, like my timer/frequency counter, signal generator and other stuff. I also needed a way of distribute a 1 PPS signal from my Trimble GPSDO to my NTP servers and other clocks and monitoring systems. The Trimble only got two 10 MHz outputs and one 1 PPS signal output, so I really needed to add more, especially for experimentation. I saw this video by Gerry Sweeney where he modifies an Extron 300MX video distributions amplifier, adding a rubidium reference standard and was intrigued. But I changed the modifications to fit my needs and here is the result.
Warning: as of yet, there is no official support for overclocking the Raspberry Pi 3, so you could damage your small computer. Just a reminder… The new version of Raspberry Pi 3 was released yesterday, so I naturally had to get two. I’m using two as Stratum-1 NTP servers and with the old Raspberry Pi 2 I […][Continue reading]
I have two Stratum-1 NTP servers using Raspberry Pi 2’s as servers. But the two setups are quite different. This is my main NTP Stratum-1 server. It is available at ntp.jacken.se but it is also in the .se pool of ntp.org. It’s a Raspberry Pi 2 I use a Raspberry Pi 3 that I have connected […][Continue reading]
The last couple of weeks I’ve been busy building a Raspberry Pi 2 Raspberry Pi 3 connected to my Trimble GPSDO using the 1 PPS output. The Trimble unit synchronises with the atomic clocks onboard the GPS satellites, and the precision is amazing! I bought the GPSDO to get a 10 MHz lab reference for my measure equipment, […][Continue reading]