Is a dedicated frequency counter a must in a decent lab? - Page 1
Forum section: electronics / testgear

author: hansibull
author_rank: Regular Contributor
timestamp: November 12, 2016, 07:50:59 pm
content: Hi!I'm slowly building up my own lab at home, and got already a hacked Rigol DS1054Z oscilloscope, and a few Fluke multimeters.I'm able to get my hands on a Fluke/Philips PM6662 frequency counter with the extra channel B (up to 1.3 GHz) installed. The price is about 150$ shipped. I already have a ~100 MHz frequency counter in my scope. Is a dedicated frequency counter something every EE with respect for him self should own? Is this a no-brainer, or is it even a useful tool when I have a digital oscilloscope?

author: nctnico
author_rank: Super Contributor
timestamp: November 12, 2016, 08:39:54 pm
content: I think I use a dedicated frequency counter once ever 5 years or so. I have a HP5334 but I have no idea if it even works if I need it. The frequencies showed on my oscilloscopes are good enough for 99.9% of my R&D work.

author: retrolefty
author_rank: Super Contributor
timestamp: November 12, 2016, 10:24:01 pm
content: Yea, I'm taking a minimalist route for a freq counter:http://www.ebay.com/itm/361726006929?_trksid=p2057872.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

author: karoru
author_rank: Regular Contributor
timestamp: November 12, 2016, 10:31:33 pm
content: Quote from: hansibull on November 12, 2016, 07:50:59 pmUnless you need to tune a radio (i.e. transmitter for bands that requires you to transmit at particular channel, as for receiver a little misalign doesn't matter) you won't ever need one. If you want to rationalize spending some pocket money or a nice toy of course go for it, it's a nice piece of hardware to get yourself as a treat for birthday/christmas/whatever day you prefer to utilize for that, but nothing more:)

author: 2N3055
author_rank: Super Contributor
timestamp: November 12, 2016, 10:46:02 pm
content: I made a few products that needed precise timing, and to be calibrated to same frequency... So I bought a counter for that...But you don't need it very often..If and when you do you'll know..

author: David Hess
author_rank: Super Contributor
timestamp: November 12, 2016, 11:04:12 pm
content: The Fluke/Philips PM6662 is a pretty basic frequency counter but apparently so is the frequency counter built into the Rigol DS1054Z which I guess only reads out frequency to 6 digits. I would not bother with such a minor upgrade in capability unless I had a specific application in mind like measurements to 1.3 GHz.My favorite not quite low end frequency counters are the old HP5315 and HP5316 which are universal reciprocal counters so they can do much more than the Fluke/Philips PM6662 or Rigol DS1054Z. They can be had on Ebay for less than $100 but of course you run the risk of a non-working instrument.

author: G0HZU
author_rank: Super Contributor
timestamp: November 12, 2016, 11:18:39 pm
content: I think the 6662 is a 9 digit reciprocal counter so in this sense it may have extra appeal for some applications. I've got an old 1.3GHz Philips 6669 counter here which is probably the same inside but has extra features on the front panel.There are a few downsides with this counter model though.The LCD display is very gloomy and difficult to read at certain angles unless you have favourable lighting on the counter, the standard timebase oscillator has a fairly poor spec for accuracy especially over temperature and the filtered rear mains power connector is one of the Schaffner types that is known to have exploding caps inside that cause the black plastic goo inside the connector to melt and spew out smoke.$150 seems a lot for a 6662 model today. I paid £85 for my PM6669 back in the early/mid 1990s.

author: David Hess
author_rank: Super Contributor
timestamp: November 12, 2016, 11:48:04 pm
content: Ah, so it is a reciprocal counter which I guess produces 7 digits per second. That makes it nicer but I agree $150 is high considering what other used instruments are available for less.

author: lmester
author_rank: Regular Contributor
timestamp: November 13, 2016, 01:11:48 am
content: I have an HP 5335A. It's on the far end of my equipment shelf. It's one of my lesser used instruments. I sometimes work with microcontroller circuits that deal with precise timing. I also have a GPSDO reference. If you need to accurately measure quartz crystal derived frequencies you'll need not just a counter but a good reference clock for it.99% of the time I just use the counter built into my scope.

author: coppice
author_rank: Super Contributor
timestamp: November 13, 2016, 05:17:13 am
content: Most labs don't have any frequency counters these days. If you work at customer sites, and need a counter for what you are doing, you'd better check in advance if they have one. If not, take your own.

author: tggzzz
author_rank: Super Contributor
timestamp: November 13, 2016, 07:59:12 am
content: Rule of thumb: if you can't articulatewhyyou need something, then you don't need it.Without further information about what you would be measuring, if I had a choice between a frequency counter and a spectrum analyser, I'd choose the latter.

author: PA4TIM
author_rank: Super Contributor
timestamp: November 13, 2016, 09:10:39 am
content: If you have to ask, you do not need one.Moderns DSO's also measure frequency related parameters.I have a few VNA's and SA's, all klind of bridges, several calibrators and standards, a high resistance meter (up to peta-Ohm), 6,5 and 7,5 benchmeters, noise analyser, a slotted line etc, that does not mean every lab needs those too.I have several counters and I use them, but not often. How often depends on the type of gear I get here for repair. I never had a HV diff probe but I often missed one so I bought one. And not just because every lab should have one.Buy things you need.

author: Ginettag20
author_rank: Regular Contributor
timestamp: November 13, 2016, 08:06:18 pm
content: I bought one to keep my bench DVM company.Chris

author: hopski
author_rank: Regular Contributor
timestamp: November 13, 2016, 08:20:14 pm
content: Ha ha. Me too, they do get lonely.

author: David Hess
author_rank: Super Contributor
timestamp: November 13, 2016, 08:31:42 pm
content: Quote from: PA4TIM on November 13, 2016, 09:10:39 amThey do but they are low performance compared to a dedicated frequency counter although I am not sure why this is. Maybe high end DSOs do better?

author: 2N3055
author_rank: Super Contributor
timestamp: November 13, 2016, 08:53:07 pm
content: Quote from: David Hess on November 13, 2016, 08:31:42 pmNot really... no 10-12 digits resolution and base timebase accuracy and stability of a good counter..But most scopes (even likes of Rigol) have counter that's good enough for generic work...And cheap counters are not much better than those on scopes...Cheapest counter I found that made sense was TTi 930/960.. It is basic 10digit counter, but good for what it is.. If you need better, you need to go name brands..Also , surprisingly, Rigol DG1032Z AWG (and its 1000Z brothers) has very decent counter channel, not fast, but it has basic analysis functions... Not bad for free....