Hitachi V-212 scope, Simpson 420A function generator, and advice on probes. - Page 1
Forum section: electronics / testgear

author: bsg
author_rank: Newbie
timestamp: March 25, 2025, 03:08:04 pm
content: Greetings everyone.I am about to spring for the test gear pair mentioned in the title; €150 for them (inc. shipping), they work (but have been shelved for a a while), but have no probes or cables.I was only looking for a scope -- where I'm at, second-hand stuff is always €100 or more -- but managed to deal for the pair as they were clearing out inventory. It's a basic 20MHz Hitachi V-212 with 2 channelshttps://www.radiomuseum.org/r/hitachi_dual_channel_oscilloscop.html, and a 1MHz Simpson 420A function generatorhttps://www.radiomuseum.org/r/simpson_function_generator_420a_420d.html.For a beginner who plans building projects on the Pico or Arduino platforms (at least for quite a while), I reckon this is all I need to get started. I may well need to do some maintenance on them (I already know the Simpson's transformer needs to be resoldered for the 220V pin, and its BNC connectors look mangy on the pictures, so I may replace them). As good a place as any to get started with electronics (I know to stay extremely away from the CRT section in the scope, in case I need to go in and fiddle with the trimmers; that is what this forum is for). Any thoughts on my choices?As the gear comes without probes, I need to source them myself; I found these:https://www.amazon.es/-/en/dp/B08XMGGJ11; I reckon that those probes are all I need, and that BNC-to-BNC will let me connect the generator to the oscilloscope, and the BNC-to-clips will let me connect it to any project. More thoughts?Thanks!

author: egonotto
author_rank: Super Contributor
timestamp: March 25, 2025, 03:37:43 pm
content: Hello,a 20 MHz analog oscilloscope and a 1 MHz generator are useful for working with analog circuits.But not so well suited for working with Pico or Arduino.In my opinion, a used Analog Discovery, for example, would be much more useful.Best regardsegonotto

author: bdunham7
author_rank: Super Contributor
timestamp: March 25, 2025, 04:06:35 pm
content: The probes are fine for that scope. Are you selecting this scope because you want an analog CRO or because you have a low budget? Those Hitachi V-xxx scopes are fairly decent for what they are, but a basic analog scope might not be as useful as you think.

author: bsg
author_rank: Newbie
timestamp: March 25, 2025, 04:18:37 pm
content: Quote from: egonotto on March 25, 2025, 03:37:43 pmI won't be probing the Arduino or Pico proper (I think), it's more for all the sensors, actuators, and so on that would connect to them.Quote from: bdunham7 on March 25, 2025, 04:06:35 pmThanks for the tip. Budget-wise, I'd rather not jump directly onto a Keysight or something like that straight away. And yes, I'd like to have a knob-laden CRO on my bench.Quote from: bdunham7 on March 25, 2025, 04:06:35 pmI have to start from somewhere, and while I've been told I should have a scope with digital storage, even if analogue, there are none on the Portuguese 2nd-hand market, and sourcing something like that from eBay with the associated shipping costs (even from the EU), would start to make sense to just buy a new, modern Siglent.Thanks to you both.

author: TimFox
author_rank: Super Contributor
timestamp: March 25, 2025, 04:34:07 pm
content: For ‘scopes in that frequency range, the important spec for a probe is the range of ‘scope input capacitance for which the probe compensation can be adjusted, compared with the actual input capacitance of the ‘scope. This is rarely a problem for that range. The probe compensation is usually a screwdriver adjustment near the connector to the ‘scope front panel.

author: bsg
author_rank: Newbie
timestamp: March 25, 2025, 04:40:36 pm
content: Quote from: TimFox on March 25, 2025, 04:34:07 pmThe scopes list the following (for what it's worth):max input voltage: X1: <200 V DC Peak AC; X10: <600 V DC Peak ACinput capacitance: 10X:13-17pF; 1X: 70-120 pFcompensation range: 10 - 35 pFThe scope itself has one trimmer next to each channel input, labelled "DC BAL"; is this balance adjustment it?Thanks

author: TimFox
author_rank: Super Contributor
timestamp: March 25, 2025, 04:51:52 pm
content: Quote from: bsg on March 25, 2025, 04:40:36 pmThose are probe specs. You need to compare “compensation 10 - 35 pF” with the input capacitance spec of the ‘scope.“DC balance” is a ‘scope control: you adjust it so that the zero level (vertical position with no input) remains constant as you change the “volts per division” switch through its range. The compensation adjustment is part of the probe assembly.

author: bsg
author_rank: Newbie
timestamp: March 25, 2025, 05:07:18 pm
content: QuoteFor the "Vertical Deflection System" for either channel, it has an input impedance of approximately 1MR in parallel with 25pF; the same for "External trigger input impedance".Apologies for not being quicker on this, but I'm learning, and the scanned manuals available are not OCR'ed.

author: TimFox
author_rank: Super Contributor
timestamp: March 25, 2025, 05:13:26 pm
content: That is a typical ‘scope input capacitance, well within the probe’s range of 10 to 35 pF.The manuals for the probe and ‘scope should tell how to use the ‘scope’s calibration output and probe’s compensation trimmer to get optimum results.