0014 HP 435A Power Meter Repair

Part 4 of the Power Meter / Sensor Series. Pete fixes a broken HP 435A Power meter.
Along the way he has to wait 1 month for UPS to make a delivery, then the meter develops a new fault mid repair.
Overall Peter replaces or repairs the knobs, the meter scale, the power supply; he adjusts all the amplifier stages, tests and replaces a lot of expensive tantalum capacitors and finally diagnoses the cause of the three uW ranges being out of specification.
Finally it works!!

Overall cost of repair £25, mainly for tantalum capacitors and about 15 hours spread across 2-months!

RF Power Meter Series Episodes
1. Power Meter Modification - https://youtu.be/PMsH562xroo
2. Sensor Chopper adjustment - https://youtu.be/YiRBuvGd0qM
3a. Calibrator Build (design) - https://youtu.be/VLkvqzXmRDA
3b. Calibrator Build (build and fault finding) - https://www.youtube.com/watch?v=BCZHe3YkCxk
4 - Meter Repair


Service Manuals and Links
8484A - https://www.keysight.com/gb/en/assets...
8480 Series - https://www.keysight.com/gb/en/assets...
Operating and service - https://www.keysight.com/gb/en/assets...
H01 Option - https://www.keysight.com/gb/en/assets...
435a service http://ftb.ko4bb.com/getsimple/index.... get the 70M version for schematics