| General > General Technical Chat |
| HP 33120A waveform is distorted. Video inside. What is going on? |
| << < (6/9) > >> |
| fran:
Even though I pulled them and they showed "ok" in a tester? Although I don't have the metal can transistors, I'm sure I'd have something I can substitute in to test at least.... I'll have a go and report back. |
| fran:
For info - the two output transistors are 2n5109 (npn) and 2n5583 (pnp) Long obsolete now in both cases - what would be recommended as a replacement - the signal generator goes to 15MHz. |
| fran:
OK, scrap that last post. I put in a pair of B139/BD140 that I had in the stash - the clipping is still there..... so I think its not the output transistors. |
| nctnico:
Get an oscilloscope and trace the signal path. That will be more fruitful than randomly replacing parts. Before anything else: check the power supply rail voltages. I assume there is a service manual available for this unit; start by going through the fault finding flowchart. |
| fran:
Good advice. The signal is OK all the way to the output amplifier - so this is where the fault lies but it is complicated, hence me scratching around looking for info and help. Voltages are all OK. |
| Navigation |
| Message Index |
| Next page |
| Previous page |