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Parallax USB Scope (Not Prop Scope) Leads? — Parallax Forums

Parallax USB Scope (Not Prop Scope) Leads?

rwgast_logicdesignrwgast_logicdesign Posts: 1,464
edited 2013-05-26 00:51 in General Discussion
The other day I got one of the older Parallax USB Scopes, these scopes have been discontinued for a long time. Anyways it is second hand with no leads, I was wondering if anyone knew where leads can be purchased? The scope doesn't use standard coax probes, it uses what look like barrel connectors found on power adapters. I could make my own but that is kind of shoddy, I could also convert the thing to BNC probes but i'm not sure if this scope is set up for standard impedance value found in common BNC probes.

Comments

  • PublisonPublison Posts: 12,366
    edited 2013-05-24 16:49
    rwgast_logicdesign wrote: »
    The other day I got one of the older Parallax USB Scopes, these scopes have been discontinued for a long time. Anyways it is second hand with no leads, I was wondering if anyone knew where leads can be purchased? The scope doesn't use standard coax probes, it uses what look like barrel connectors found on power adapters. I could make my own but that is kind of shoddy, I could also convert the thing to BNC probes but i'm not sure if this scope is set up for standard impedance value found in common BNC probes.

    Guess you could get some brand new ones...and a backup O'scope.

    http://www.ebay.com/itm/ws/eBayISAPI.dll?ViewItem&item=111037065061

    Or wait till Tuesday and call Parallax.
  • RDL2004RDL2004 Posts: 2,554
    edited 2013-05-24 18:59
    I'd just make some. I have one of those scopes, the leads are just regular DC power connectors with "mini-grabber" clips on the other end. Each "probe" does have some kind of braided cover over most of the length, but basically it's just some wire with a plug at one end and some clips at the other.
  • rwgast_logicdesignrwgast_logicdesign Posts: 1,464
    edited 2013-05-25 15:25
    RDL could you measure the resistance between the + on the barrel connector and the + grabber?
  • RDL2004RDL2004 Posts: 2,554
    edited 2013-05-26 00:51
    They're definitely just straight through wires. All three measure around 0.3 - 0.5 ohms on both positive and negative (Fluke 87-III). Probably some contact resistance is being measured there, I wasn't using my best probes. They're all wired up with center positive.

    The barrel connectors are about 4.0 mm o.d. x 8.0 mm long. I don't think 4 mm dia. is a common size. I couldn't get a good measurement on the center pin. It's pretty small, not the usual 2.1 mm. The meter probes I was using are about 1.95 mm dia. and they wouldn't fit inside the barrel connector, so probably 1.5 or 1.8 mm.
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