Anyone know what Circut Bob Pease was going on about?

We have an SRS SC-cut ovenized oscillator, that we mounted in a rack box with a power supply. Ditto an ebay rubidium. We even have an old HP cesium standard, which is a big deal to fire up, so we seldom use it. All three typically agree to something like 30 ppb.

Cool: trigger a scope from the cesium and look at the rising edge of the rubidium, at 10 ns/cm. Ten minutes later, it's barely moved.

But still, a grand for a TCXO is insane. It probably costs them 20 bucks or so. So, no Agilent counter.

John

Reply to
John Larkin
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Spend you money on a GPS-based super-accurate 10MHz reference to use all around your lab.

Reply to
Winfield

We already have some good 10 MHz sources. But it's a nuisance to have to connect a small, portable counter to a big reference source.

Why a grand for a TCXO?

John

Reply to
John Larkin

It should not be. Run some dedicated cables, put on a particular color of heat shrink, leave them there like air hoses or electrical outlets.

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Reply to
Ecnerwal

Distributing 10 MHz all over two floors of a building would be a major project... just for the benefit of one Agilent counter. Ethernet was bad enough.

John

Reply to
John Larkin

we did that at the capacitor company I consulted at on the side.

GPS time base receiver (10 mhz output), into a distribution amplifier with isolated outputs (20 count). each rung went to a work station to be used as the reference for capacitor testers.

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Reply to
Jamie

I'm sort of surprised that you only have one thing (which you don't even have, if I understand correctly, since you don't want to buy it without the OXCO, and the OXCO is overpriced) that would benefit from easy access to a reference frequency, especially since you have already bothered to get in several reference frequency sources.

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Cats, coffee, chocolate...vices to live by
Reply to
Ecnerwal

So they can sell the 'stripped' version for a grand cheaper to the penny pinchers? Maybe something like that.

Reply to
Spehro Pefhany

The way I read it, I assumed John was talking about pulling all that cable.

Thanks, Rich

Reply to
Rich Grise

Yes, I got that. I just find it hard to justify not doing so as "it's only for this one meter I haven't bought, so why bother."

Obviously there _are_ other things which he does have that benefit from good references, or he would not have any of those, much less several.

Thus, a one-time painful cable-pull-fest would make all those applications, and any future ones (even if he never buys the particular counter in question) easy, rather than a hassle. It's sort of like "Why go to the bother of running all that pipe, when I can get water in a bucket?" Or "Why go to the bother of running all that pipe, when I can drag out a portable air compressor and a hose if I need compressed air?"

The way you use things, be they water, compressed air, or 10MHz reference frequencies, changes depending on how much of a pain it is to access them. I suspect that the price of one new counter without OXCO might cover a fleet of older ones from *B*y that will be just fine if they are fed a known-good reference. Some signal generators can also take an external reference for greater precision, if there's one coming to the bench anyway.

Enough, I'll stop here.

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Cats, coffee, chocolate...vices to live by
Reply to
Ecnerwal

We have a bunch of HP5370B's, which are 20 ps single-shot time interval counters, that also do frequency to 100 MHz. They all seem to stay within 30-50 ppb of the rubidium, so they don't really benefit from an external reference. But they're 4U rackmount beasts, not something I want in my office mini-lab. I'm in the market for a nice little "universal" counter, preferably new, and haven't found anything really suitable.

My Keithley 2100 DVM is a pretty good frequency counter, too, so maybe I'll just wheel over a 5370 when I need something serious.

Heck, my TDS2012 is a pretty good counter, too.

John

Reply to
John Larkin

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