Hitachi V-152F questions

Thread Starter


Joined Oct 26, 2019
I recently got this Hitachi V-152F from a thrift store, and I have some questions.

1. Does anybody know about a SPEAKER being in one of these? This is really bizzare for me. It's in the back corner underneath the transformer and it will sometimes wail at different volumes when I am looking at waveforms at different settings. I have never heard anything about an oscilloscope having a speaker and I don't see it on the schematic, although it's easy to overlook something on it. The manual does not mention it.

2. On this shoddily repaired PCB next to the CRT, these heatsinked components run about 100+ F on my IR thermometer. I don't smell burning, but I can smell the heat, if that makes sense. (The effect may be enhanced by the fact it's kinda dirty inside) Is that normal?

3. The knobs cause those jittery traces typical of (abused) analog scopes. What's a good contact cleaner safe for the plastics used to make the wafers, pots, and knobs?


Thank you