R&S EB200 Miniport Receiver Dial Knob
I was lucky enough to get a Rohde & Schwarz EB200 Miniport receiver in working but less than mint condition. Apart from cleaning and fixing some bumps on the covers, the dial knob was very broken. This knob is a custom part designed by R&S that proved impossible to get in 2023. Repairing the original […]
Elecraft K3 “ERR 12V” Fix
The Elecraft K3 is a very well known HF transceiver with a great reputation and it follows quite a different philosophy from what (mainly japanese) competitors were offering at its time. This particular unit, from my good friend Angel EA4XT started giving “ERR 12V” and the output power dropped to a few watts each time. […]
Rohde & Schwarz FSIQ IF-Filter Module Repair
The result of buying a “defekt” FSIQ unit from eBay Germany was that I ended up with a huge instrument lying around for months, with little hopes of ever getting it repaired. The RF CONVERTER module had a (unrepairable for me) YIG unit and I managed to get a used, but working, RF CONVERTER module. […]
KORG MS2000 synthesizer repairs & restoration
This is a legendary synthesizer with many knobs that allow for direct-access to many functions. It sounds great, looks great, and it is a great tool to learn about analog sound synthesis, but there are better synths now and it is difficult to justify the usual price. I came across a beaten unit, non working […]
Tektronix MDO3014 50 Ohm inputs repair
My MDO3014 oscilloscope seemed to work fine with the high impedance probes but when I checked the inputs at 50 ohm with the fast risetime pulse generator from Leo Bodnar (link) the traces did not look right… three of them clearly showed ringing: Checking the input impedances The first thing […]
Emcomat 7 Cross-slide nut
My Emcomat 7 lathe was suffering severe backlash problems in the crosslide. Taking it appart I found the crosslide nut had given up, the anti-backlash adjustment had gone too far and the threads were worn. I was not able to find a replacement so I took measurements of the old nut and machined a new […]
Lecroy LT342 Repairs
I managed to get a cheap “for parts” oscilloscope that arrived with a dark screen, damaged CH1 BNC connector and broken ground terminal. One knob was missing and the floppy drive did not work. The encoders where hard to use, very erratic. You turned them fast and nothing moved and you turned them slowly and […]
Mitutoyo Indicator Battery Cap
I managed to get a very cheap Mitutoyo digital indicator, the reason being the battery cap was missing, and it required one ugly and very unreliable piece of tape to hold the battery in place. It seemed like a good excuse to do something useful with the CNC. I carefully measured the dimensions and thought […]
IC-R8500 Low Sensitivity
I was happy with the IC-R8500 until one day I used a splitter to connect another receiver along this one to the same antenna at the same time, and I found it was performing a worse than the other. Moderate signals were readable on both but I could hear clear voices on the other than […]
HP 70004A Repair
I bought this cheap 70004A color display as faulty. I was happy to find it actually worked… or so it did for a few months. One day, it refused to turn on. I could see the power LED flash briefly upon turn-on and then… silence (pretty easy to tell with your eyes closed if this […]