Frequency Counter Suggestions - Page 1
Forum section: electronics / general

author: paulpthcom
author_rank: Contributor
timestamp: January 18, 2011, 10:01:26 pm
content: Hi All,I'm looking for a frequency counter < $200. At least up to 100MHz and as accurate as possible given the budget. There's a number of cheap chinese models and also a number of used discontinued agilent/fluke/etc... devices for that price range.Can someone with experience in these provide some good models to look at or even bad models to avoid?

author: PeterG
author_rank: Frequent Contributor
timestamp: January 19, 2011, 02:00:48 am
content: I got myself one of these.http://www.dealexcel.com/new-precision-frequency-counter-vc3165-001hz-to-24ghz-sku590_p590.htmlIt seems good enough for what i need. For the price you cant really go wrong.My 2.2cents.

author: saturation
author_rank: Super Contributor
timestamp: January 19, 2011, 02:07:10 am
content: A basic FC is one that provides highly accurate counting with error all under 5 ppm, but has few control over sensitivity or can make other measurements beyond period, which is simply 1/f. The top $1000+ models from Agilent do pulse width, duty cycle etc., but you should do those better with a scope rather than pay extra for those functions on an FC.The Rigol 1052E comes with a decent FC built in, capable of measuring to the scope's bandwidth.Handheld models have most basic functions but are easier to transport like a DMM, and if you stick an antenna on them, can test radio output. The LT Lutron, or RSR are current models sold that were once a rebadged B&K ~4ppm accuracy, from 1Hz to 2.5GHz. They sell between $150-250. I have one of these. A good one out of production was a Global Specialties model 3005, that is still sold as a Tenma brand. There is one at eBay new for just $100, normally $270 new.A popular one on eBay is the Victor :If you can find someone who will offer replacement warranty for damage, this Victor works very well and often are sold by US eBay sellers, so it helps if you get a dud! Its a 2.5GHz counter that typically sells for under $90. It has decent rating among Ham radio guys, major complaint is quality control.http://www.eham.net/reviews/detail/7839Other than these, the usual brand names like B&K, Protek, Heathkit, Elenco etc., have old second hand benchtop models on eBay that will read to 100 MHz or nearby, for under $100. 100 MHz was typical for older circa FC, but the same amount of money or just slightly more will get you a new and more accurate one for >= 1 GHz, so I don't think old frequency counters are competitive today, considering many function generators throw in a multi-MHz frequency counter in for free.THe $100 Hantek DDS FG 3x25 I reviewed elsewhere on eevblog includes a 5 digit FC good to 100MHz.

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: January 19, 2011, 02:29:45 am
content: This is what I have , and I do not do RF stuff any more .It works with four batteries , and has an input for 6V DC.Five digits display.I used to adjust FM PLL synthesizers with it.If you have paypal , and you like it , send me PM ..

author: slburris
author_rank: Frequent Contributor
timestamp: January 19, 2011, 04:28:05 am
content: I have the Racal Dana 1998 counter I got off of Ebay for about $80.Nicely accurate 1.3Ghz counter. The service manual is available,and it provides for an external 10Mhz reference input, so if you havea GPS locked frequency reference like a Trimble Thunderbolt, you'll havean extremely accurate counter.Scott

author: Unknown
author_rank: Unknown
timestamp: January 19, 2011, 06:07:53 am
content: Accuracy is mainly determined by the reference clock (accuracy of the counter is often something like +/- 1 count without prescaler), so an external reference input is very useful if you want better accuracy in the future (assuming it has the resolution, not much point in 1ppm accuracy for a four digit display, might as well use a scope for that). Standard XO (crystal) is cheapest, TCXO (temperature compensated) is better, and OCXO (ovenized) is best. All can be disciplined with GPS for excellent long term accuracy. The expensive counters have a replaceable oscillator module than can be replaced by eg. an ovenized crystal. IMO frequency counter should offer better accuracy and resolution than a DSO, otherwise it's just a convenience item. There may also be some good deals on the used market, something like $250 sounds kinda steep to me.If it's not shipped with a calibration certificate (unlikely for $200) or used, try to find someone with an accurate reference clock (eg. GPS) nearby to verify/adjust your reference to.

author: Bored@Work
author_rank: Super Contributor
timestamp: January 19, 2011, 06:56:31 am
content: Quote from: alm on January 19, 2011, 06:07:53 amYou missed the rubidium standard. The rubidium standard does the short term stability while the GPS does the long term stability.You get rubidiums standards rather cheap on e-bay. They are used, and typically are at or beyond the manufacturer's guaranteed lifetime. That's whey they have been replaced. They are out of spec and would require adjustment, which you can't do without access to a very good reference. Here comes the GPS into play.There is a mailing list out there, called Timenuts. They know how to do it right.

author: Unknown
author_rank: Unknown
timestamp: January 19, 2011, 08:54:39 pm
content: Quote from: BoredAtWork on January 19, 2011, 06:56:31 amYou're right, and I also missed cesium (and I think there are even more exotic standards out there).Quote from: BoredAtWork on January 19, 2011, 06:56:31 amAbsolutely, although they might blow that $200 budget.

author: Bored@Work
author_rank: Super Contributor
timestamp: January 19, 2011, 10:22:47 pm
content: Quote from: alm on January 19, 2011, 08:54:39 pmOnly that rubidium standards are affordable. From $60 onwards on e-bay.

author: paulpthcom
author_rank: Contributor
timestamp: January 19, 2011, 10:48:53 pm
content: Thanks for the detailed reply, more below.Quote from: saturation on January 19, 2011, 02:07:10 amI have the 1052 but unless I'm missing some setting somewhere the FC doesn't have a very good resolution, off the top of my head I want to say 3 digits and it jumps around a lot. It's for sure useful but doing something like verifying that a 32k watch crystal + capacitors is working precisely is not something it can do.Quote from: saturation on January 19, 2011, 02:07:10 amThanks for the link to the reviews it was one of the ones I was looking for but as with most of this type of equipment its hard to know if its good or junk just from the manufacturer's description.Quote from: saturation on January 19, 2011, 02:07:10 amThis was one of the big questions I had whether the old stuff provided any compelling advantage over the newer equipment, sounds like not.

author: paulpthcom
author_rank: Contributor
timestamp: January 19, 2011, 10:54:51 pm
content: Quote from: Kiriakos-GR on January 19, 2011, 02:29:45 amThanks for the offer but just looking at the number of digits on the display doesn't seem like there's enough digits for what I'd want.

author: saturation
author_rank: Super Contributor
timestamp: January 20, 2011, 12:28:27 am
content: Quote from: paulpthcom on January 19, 2011, 10:48:53 pmwelcome, there are 3 counters in the 1052E, 2 on the 'Measure' Menu, when you choose TIME then scroll down, or Display All measurements, and the most accurate one is in the Utility Menu, its 6 digits. The Utility counter's first 5 digits are identical to my 8 digit B&K, and this counter works independent of any timebases or Voltage setting.Quote from: paulpthcom on January 19, 2011, 10:48:53 pmThe Victor 3165 either works or doesn't. If you buy it from a US dealer, you can return it like the ham radio group discusses. There are more reviews, elsewhere, just check google. The Global Specialties counter on eBay is $100 to 3 GHz, only one for sale. Its the same model as the Tenma sold for near $300.http://cgi.ebay.com/Global-Specialites-5003-Handheld-Frequency-Counter-NEW-/320634778367?pt=LH_DefaultDomain_0&hash=item4aa75272ffQuote from: paulpthcom on January 19, 2011, 10:48:53 pmMany of the ordinary old counters are XO and construction of counters is pretty generic, like DMMs. But if you can find top lab gear on eBay, like slburris' Racal Dana, that's best. You can recognize highe quality if they have external clock outputs, which is more desirable that ovenized, due to the availability today of GPS reference clocks. Decent counters are precise to some number of digits. The differences the drives costs up are accuracy against the NIST clock, and then more digits.For under $200 a GHz counter there is also the Mastech which is 1.3 GHz.http://www.amazon.com/Mastech-Multi-functional-Frenquency-Counter-MS6100/dp/B00066N8I4

author: paulpthcom
author_rank: Contributor
timestamp: January 20, 2011, 02:14:38 am
content: Quote from: saturation on January 20, 2011, 12:28:27 amDoh, I hadn't seen that one in the Utility menu. That makes the decision quite a bit harder since while its not as accurate as I'd like its basically free and I can probably work around the limitations.

author: saturation
author_rank: Super Contributor
timestamp: January 20, 2011, 01:27:45 pm
content: Great, then if you can wait, hunt on eBay for a top quality FC, as slburris, alm, B@W have specified, and slburris suggests can be found potentially for < $100. For best results:external clock input or ovenizedat least 8 digits or moreMy impression is you needed a 'good' one now to 100MHz.But if you can wait and have no pressing need right now, write down specifically your accuracy limits, say in ppm, frequency stability in ppm, and number of displayed digits. For a rubidium counter, accuracy or drift is in pptrillion.You can get near rubidium accuracy for ~ $200; basic externally clocked counter $100, Trimble GPS clock ~ $100, the trick is finding the counter!A patient hunter waits for good prey and an easy kill, so you'll have to watch ebay and wait until a deal comes through. Most of what's typically available are ordinary XO whether new manufacture or old used and working.FWIW, accuracy is needed for radio applications in order to make tuning frequencies spot on. Beyond that, relative accuracy works for non-radio designs, thus XO is adequate.Quote from: paulpthcom on January 20, 2011, 02:14:38 am