B+K (Dynascan) Model 430 Signal Meter

[Cyberdragon]

More auction junk, YAY!

The old battery pack will still hold some charge, enough for it to work a little while. But the needle won't stop twitching everywhere when you try to tune it, along with static noises coming from the speaker. This happens even connected to the calibration output with a short piece of F connector coaxial. I've tried cleaning some of the controls and tightening the internal F connectors. The attenuator switches might be dirty but they are sealed in a shield box that would horrible to get apart (looks like solder and bent metal tabs). Tried spraying cleaner from the top of the switches with no affect. Anything else that could cause this? I've also noted that it can't be operated while charging because it makes the problem worse and causes buzzing and crackling from the speaker. Is this also a problem or is this normal?

As always, any (free) manuals or schematics are appreciated.

[PA0PBZ]

If it is tuned by one of these old-fashioned air variable capacitors it could be that the rotating contact needs a good cleaning:

[Cyberdragon]

Nope, Just a tiny VR on a big clear knob. Along with another tiny pot on some sort of pull switch labeled "Fine Tuning". It has two exposed circuit boards and four shield cans connected together with coaxial cables on F connectors and some pin header connectors.

[PA0PBZ]

Try to clean the pots.