Help me figure out the best frequency counter to keep.

[PoDuck]

It is time to start getting to all the projects I have long intended to get to, but haven't, because I'm starting to feel claustrophobic with all the junk encroaching. First thing I'm working on is frequency counters.

I seem to have a problem with acquiring frequency counters, and I am sitting here with four of them in various stages of usefulness. I have one that isn't on the chopping block that I am keeping, but I have three candidates for getting rid of.

I have an HP 5340a that has an OCXO that is spot on according to my recently calibrated main frequency counter, but it has issues with the digits not displaying correctly. I'm not sure how bad the problems are with it, since I can't tell if it is reading anything or not due to the display. I have an HP 5328A, also with an OCXO, that is about 300 - 500 Hz off frequency, and not terribly stable in that range, for some reason. And finally, I have a fluke 7220A that seems to be bang on frequency, and although it doesn't have an OCXO, it is as stable as my hands were before I had kids, but it won't read much of anything unless I amplify the signal first.

I want to pare these down to the best one of them to use as a backup, but I'm not sure which one would be most worth keeping, considering that I can fix them, of course. I've never used any of them other than to do some light testing of them to see what was wrong with them, so they have always had their issues since I've had them. Does anyone have any opinions on these? How would you rank these, if they were in working order?

 

[nomadradio]

Reminds me of a "Fabulous Furry Freak Brothers" cartoon from the 70s. They want to take a road trip. They have two cars, an MG and a rear-wheel drive Chrysler. But the MG has a bad transmission. Expensive parts from England are not an option. They have a Chrysler with a broken steering gear, but good power train. They drive the Chrysler up onto the back of the MG and tie them together with ropes. Steer with the MG and push with the Chrysler. I think I'll skip the punch line for now. Probably not PC.

A counter that's a steady as the Fluke with better input sensitivity sounds like what you want.

I would probably favor the Fluke, just because it's not so incredibly old. My favorite input preamp was the Tek 465 with the "Channel B output" jack. Loved that feature. Kept a counter jumpered to it until the last 465 took a bad dive. I could count any signal the 465 could see, with no more circuit loading than a 10-to-1 probe causes.

And a preamp should not be a terrible challenge to whip up.

Your mileage may vary.

73

 

[PoDuck]

I plan on fixing all of them. The 5328A I'm sure just needs an alignment. The fluke, for some reason has the most miserable sensitivity I've ever seen. I have a few of those little amplifier boards laying around that you can get cheap on ebay and Amazon. They work pretty good, but sometimes even those won't amplify signals enough for the fluke. I think there might be an easy fix for it though, because sometimes it works just fine.

The 5340A I like just for the cool factor of the nixie tubes alone, much less the 18 Ghz capability. I'm inclined to keep that one, since most of the parts are TTL chips that is still readily available.

The three counters have quite different frequency ranges as well. The 5328A only goes to 100Mhz, the fluke goes to 1.3 Ghz, and the 5340A goes to 18Ghz, which is even higher than my Agilent 53181A.