Hi Folks

Picked one of these HP 3465a meters up today at a garage sale, and was wondering if I should change the electrolytics....HP usually uses pretty high quality stuff, so it might not be necessary....

Steve

If I remember correctly, and depending on the power/battery options you have in your meter, there are probably only one or 2 conventional electrolytic capacitors present.
The remainder will be either high quality solid tantalum or film types. No shotgun capacitor replacement needed.

Thanks!

The unit looks clean, and fortunately the NiCads had only leaked inside their cases with no spread, so they are out.

I think it will likely serve me well...the LEDs look good with only a little but of "shine" in the center line (where the middle of the 3 is...)

Steve

BTW, does anyone try to replace those NiCAds? They appear to be AA size but solidly held in the 2 packs...

Steve

Unless the Nicads are the primary power source for the meter, I'd not replace them. I know in some of their meters the power source was selected by a switch either on the rear panel or under the top cover.

In some of those bench units, the batteries need to be there as part of the power supply. I've replaced them in some, and in others just replaced them with a resistor selected the old fashioned way ... trial and error. But if the unit is using the battery pack as a filter, then you'll also need a capacitor somewhere to smooth out ripple.

Try it without the batteries and see. IIRC, my HP bench DMM just had an onboard jumper for whether or not it had the optional rechargeable battery installed. It's a 3466A

This one is an "option 001", which runs on AC with optional batteries.

Interestingly, there is no description of how to remove the "optional" batteries in the manual, and the rear access door for the batteries has the usual "don't mess with me" warnings...and it was not obvious how to remove the door...

Unit runs fine without the batteries.

Thanks!

Steve

IIRC, and I may not lol .... I had to dig into the schematics to figure out the "no battery" jumper. It wasn't mentioned anywhere in the manual that I could find. Likely a factory only option ......

Glad it works, nice meter.

AS for your original question about replacing electrolytics, I would test the cap for leakage, if you want something to do, but my experience has been that with lab grade test equipment, there is VERY SELDOM any need to replace electrolytics.

Of the couple hundred pieces of test equipment I've repaired over the years, I replaced a filter cap in a Tek 7603(?), and a Boonton 260 "Q" meter. Now if it was a $15 table top AA5 from half a century ago, I'd replace everything I could. Has something to do with product build quality I think.

The battery packs may be the same as used in old HP calculators. Here's an example of of a clone pack currently offered on eBay.
The cost for a pair from that seller however, might be more then you paid for the meter.

You could probably make up similar packs yourself from individual cells that you can buy that have pre attached solder tabs.

That said, this meter is probably best delegated to bench use anyway. Depending on the case style on yours, it's not highly portable in the first place, and operating time on batteries will likely be short even with new batteries.

- Jim