DJ9KW's HP repair chronicles

 

 

Repairing HP (and other gear) for years, I decided why not share some of my adventures on this page as gathering information is one of the hardest parts in repairing and maintaining this kind of stuff which is becoming more than 40 years old by now.

Enjoy reading along while I dive from one rabbit hole into the next :-)

Repairs
HP 856x / 859x related:

 

2025 / 07 : HP 5085-7744 LO distribution amplifier (LODA) replacement
2025 / 07 : HP 5085-7906 Yig Tuned Oscillator bonanza
Others:

 

2025 / 07 : HP 5342A power supply issues
2025 / 07 : A HP 10544A compatible TCXO replacement
2025 / 09 : HP 8660C output issues
Development, Tinkering, Reverse Engineering
  2025 / 07 : ... just another YIG: MicroLambda MLMY-1071-1 2..10 GHz YTO
2025 / 07 : Oh no! Another YTO, this time a Philips / Sivers Lab PM7020 2.1 - 8.3 GHz
2025 / 07 : One more YTO, this time an Avantek ASF-8368M 2.0 - 4.1 GHz