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Products => Test Equipment => Topic started by: ezalys on March 01, 2018, 05:45:29 am

Title: HP 5340A Sampler Voltages
Post by: ezalys on March 01, 2018, 05:45:29 am

Hey all!

Is there anyone out there with a 5340A frequency counter that can measure some voltages for me? There's a unit inside on the pre-amp assembly #1 and another on the pre-amp assembly #2 that takes +5 volts and -5 volts that generates the sampling pulses, called 5088-7005. I have one on my bench and I really don't want to blow it up, can't manage to open it, can't find any pictures on the web of how it's hooked up properly, and it has absolutely no labels on it. I'd really appreciate it if someone could figure out which terminal is the +5 and which is the -5 with a multimeter... or perhaps I've missed something in the manual. All I know from a bit of googling is that one wire is color coded red/white/black and can see what terminal it goes to, but there's no table (that I've found) that says what voltage this wire corresponds to. Maybe this is a standard HP color coding. Any ideas, folks? Thanks for checkin!

Title: Re: HP 5340A Sampler Voltages
Post by: rob.manderson on March 01, 2018, 12:43:21 pm

HP used the resistor color code for hookup wiring.  You read it as 1st digit -> body color,  2nd digit -> thicker stripe, 3rd digit -> thinner stripe.  (And if the hookup wire has no stripes then you read it as a single digit, one stripe as two digits etc). Each of those codes corresponds to the numbering on the circuit diagrams.  In your example, let's assume you've listed the colors as body/thick/thin.  That reads as 290.  So look for a connection (going to another module) labelled 290.  That's it.

Title: Re: HP 5340A Sampler Voltages
Post by: ezalys on March 01, 2018, 02:29:38 pm

The plus and minus five volt rails are only mentioned as such in the manual. There doesn’t seem to be any associated color coding or numbering. They mention the +5 rail as red/white but that might be a different five volt rail, as the wires going to the unit seem to be red black white and purple something something... maybe.

Title: Re: HP 5340A Sampler Voltages
Post by: Orange on March 01, 2018, 04:04:25 pm

I just opened one of mine, this is from an HP5340A (LED version)

Red/Black = + 5V

Purple/Gray = -5V

Title: Re: HP 5340A Sampler Voltages
Post by: Orange on March 02, 2018, 08:05:31 am

So whats up ezalys ?

Title: Re: HP 5340A Sampler Voltages
Post by: ezalys on March 02, 2018, 02:25:13 pm

Ahhh you're the best! Thank you so much. This is exactly what I was looking for.