DIY audio blog for projects, schematics, PCB's, designs, electronics, mods


Category: Measurements

Tektronix SG505 low-distortion audio oscillator

The Tektronix SG505 instrument is an ultra-low distortion and low-nose oscillator intended for testing of audio grade electronic products. This one came to my possession as a non-working unit and I set-out to fix it.

Front view. Tektronix SG505
Front view

The LPRO-101 DIY Rubidium Clock Generator

The DIY LPRO-101 ruibidioum clock generator. This box together with some additional electronics on a separate PCB will transform this LPRO unit into stand alone equipment. I’ve always wanted a good and affordable frequency standard for my home lab. Searching the eBay one might find quite a lot of solutions. The good thing is that nowadays we have plenty of options.

Low-noise Power Supply

Here is a quick article describing a low-noise power supply for low current applications. It’s simple, and easy to build. All parts are widely available and cheap. I’m using this power supply to power-up my RIAA preamplifier. It’s more that capable of delivering excellent results. Build one and try it for yourself.

First of all lets see the basic functional diagram of the regulator.

Positive voltage regulator:

Error Amplifier Low-Noise

Low Value Capacitance Meter

This circuit was originally designed to measure the volume of fluid inside a medical syringe.   As designed, it produces a zero to 5 volt output, corresponding to a capacitance change of about 10 picofarads.  With a digital voltmeter, at its output, it can resolve a capacitance change of 0.002 picofarads or 2 femtofarads.

Low Value Capacitance Meter – [[[LINK]]] 

Powered by WordPress & Theme by Anders Norén