I found a possible replacement ammeter for my HP6237B power supply. Will it work?
Today we make some simple and cheap modifications in order to address the two biggest problems in the MHS5200A function generator: sine wave harmonic distortion, and square wave ringing/overshoot.
If you want to make the same modifications, here is the Digikey BOM. Note that the capacitors and inductors I used for the Bessel filter were 0402, while the pads on the PCB are 0603; either size fits, though 0402’s are obviously a bit harder to work with.
See the pictures below for more details.
It’s time for another analog IQ test, courtesy of Jim Williams! Can we identify and stop the source of oscillation in a simple voltage reference circuit?
I got a really good deal on an HP6237B power supply on eBay, but the front panel meters had taken a beating! Luckily, my cats were there to help me try to repair it.
Today we examine question #22 from Jim Williams’ Test Your Analog Design IQ: How to get -20V out of an LM741 op-amp running from a +-15V supply?
Today we revisit the MHS-5200A function generator distortion issues, this time examining the slew rate limitations of the AD812 output amplifier, as suggested by the viewers!
I’s and Q’s and negative frequencies, oh my! Today we discuss mixers and frequency conversion, in particular, quadrature mixers and Tayloe detectors: what they are, how they work, why you might want one, and what do we use all this I and Q stuff for anyhow?
|Introduction to RF mixers||Basics of RF Mixers in Radio Receivers, Alan Wolke (W2AEW)|
|Mixer theory and switching mixer operation||Downconversion Mixers, Gino Giusi, Ph.D|
|Introduction to IQ signals and phasor diagrams||Basics of IQ Signals and IQ modulation & demodulation – a tutorial, Alan Wolke (W2AEW)|
|IQ signal processing fundamentals, Euler’s identities||A Quadrature Signals Tutorial: Complex, But Not Complicated, Richard Lyons|
|IQ phase relationships at positive and negative frequencies||IQ Modulation, Keysight Technologies|
|The Tayloe quadrature detector||Ultra Low Noise, High Performance, Zero IF Quadrature Product Detector and Preamplifier, Dan Tayloe|
After seeing WD5GNR‘s excellent work on reverse engineering the serial protocol for the cheap ebay MHS-5200A arbitrary function generators, I decided to pick one up as a secondary function generator for the lab.
What started as a simple review and teardown video ended with me reverse engineering the entire analog front end to track down the source of some nasty harmonic distortion!