UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Oscilloscope question

MotorBikeLes · 27th May 2020, 8:23 pm

Chris, not sure if you are correct. I don't recall ever seeing a tunnel diode in a Scopex.
The two common models are the 4D10 and the 4D10A. The first one used static sensitive components in the front end (BFS28 MOS-Fets), so need treating with care. The -A version used less sensitive devices, ordinary FETs, E421. (Not sure what equivalents, but possibly selected BFW10 or BFW11).
Common failures are the high value resistors in parallel with the high voltage electrolytics in the EHT chain.
My complaint about gould (aka Advace) is transformer failures.
10MHz conventional Chinese scope, never hear of them. Details please?
Les.

27th May 2020, 8:23 pm	#25
MotorBikeLes Nonode Join Date: Dec 2012 Location: Kirk Michael, Isle of Man Posts: 2,350	Re: Oscilloscope question - not vintage Chris, not sure if you are correct. I don't recall ever seeing a tunnel diode in a Scopex. The two common models are the 4D10 and the 4D10A. The first one used static sensitive components in the front end (BFS28 MOS-Fets), so need treating with care. The -A version used less sensitive devices, ordinary FETs, E421. (Not sure what equivalents, but possibly selected BFW10 or BFW11). Common failures are the high value resistors in parallel with the high voltage electrolytics in the EHT chain. My complaint about gould (aka Advace) is transformer failures. 10MHz conventional Chinese scope, never hear of them. Details please? Les.