Aliexpress frequency counters - Page 1
Forum section: electronics / projects

author: Terry Bites
author_rank: Super Contributor
timestamp: May 27, 2025, 04:13:44 pm
content: Am I going mad?Well, madder.I run a small community repair shed on Saturdays and we were looking for a cheap counter.Here's what I dont get; many Aliexpress frequency counters have a 13MHz reference output. Not 10MHz. WTFSo, does anyone know why this is and what use is there for 13MHz?Not that I'd use it as a reference anyway.

author: rvalente
author_rank: Frequent Contributor
timestamp: May 27, 2025, 04:39:15 pm
content: Old HPs 53xxx piles up on Ebay, they're just great! 75 to $100, Worth considering!

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: May 27, 2025, 05:22:15 pm
content: Surplus ex-cellular oscillators maybe

author: Terry Bites
author_rank: Super Contributor
timestamp: May 27, 2025, 07:22:44 pm
content: Cheapskates!I've decided not to mod all my old gear to use 13MHz.us South London geezers are far too stubborn for all that old malarkey.

author: PCB.Wiz
author_rank: Super Contributor
timestamp: May 27, 2025, 07:38:17 pm
content: Quote from: Terry Bites on May 27, 2025, 04:13:44 pm26MHz TCXO and VCTCXO are cheap and easily available to 0.5ppm.This will be /2 to give 50% duty cycle.You should try to find a Reciprocal Frequency Counter, but I’m not sure what Ali names those.

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: May 27, 2025, 08:24:14 pm
content: An HP5334B can usually be had for cheap. If it doesn't already have one, you can install an ovenized oscillator. They're 100 MHz, so if you need more you probably need a different model, probably not a reciprocal. At one time Optoelectronics and Startek made tons of inexpensive counters for hams, but those days are gone. Now Opto only has a couple fairly expensive ones and I think Startek is gone entirely. Should still be many on eBay.Then, of course, you need a GPS oscillator like Leo Bodnar to calibrate it!

author: mawyatt
author_rank: Super Contributor
timestamp: May 27, 2025, 08:40:38 pm
content: Agree, 13MHz makes no sense at all!!Stay away from that (and a lot of other similar AliX) stuff!!Next thing you know, they'll start with things that display in dBwtf unitsWe should all know that 2 awe-shits = -6dBwtfBest

author: amyk
author_rank: Super Contributor
timestamp: May 28, 2025, 04:00:49 am
content: Quote from: mikeselectricstuff on May 27, 2025, 05:22:15 pmBingo.https://en.wikipedia.org/wiki/Crystal_oscillator_frequenciesQuote

author: Haenk
author_rank: Super Contributor
timestamp: May 28, 2025, 04:42:33 am
content: On the other hand, that would suggest these might be not that bad as a frequency counter.

author: PCB.Wiz
author_rank: Super Contributor
timestamp: May 28, 2025, 05:49:09 am
content: Quote from: mawyatt on May 27, 2025, 08:40:38 pmAliExpress is ok, when used with care.An example is this 8 digit Frequency counter module,https://www.aliexpress.com/item/1005008284489840.htmlbased on this workhttps://www.zl2pd.com/files/PLJ-8LED_Manual_Translation_EN.pdfIt uses a PIC16F648A+2.4GHz prescaler + 2.5 ppm VC-TCXO.It gives one price/performance point.The little PIC has no capture modes in async counting modes, so it uses a simple gate-time counter, but the 1Hz LSB may be fine for many uses.

author: Datman
author_rank: Regular Contributor
timestamp: May 28, 2025, 12:14:53 pm
content: https://www.eevblog.com/forum/projects/ten-dollar-pic-100khz-2-4ghz-frequency-counter/msg2265540/#msg2265540They are very good for the price. If you want more, search for a used Racal-Dana 1992 or similar.https://www.ebay.it/itm/326603416586

author: PCB.Wiz
author_rank: Super Contributor
timestamp: May 29, 2025, 01:14:37 am
content: Quote from: Datman on May 28, 2025, 12:14:53 pmYes, a good price/performance point.Further up from Alixpress are the 'big-box counters'https://www.aliexpress.com/item/1005008463767841.htmlbut the shipping is expensive, and it is not clear if they have reciprocal resolution ?but you may get more for less, if you go more modern with a DDS Generator/Frequency Counter, as the included counter has quite good resolution.https://www.aliexpress.com/item/33042950680.htmlCharacter LCD 0.01Hz resolutionhttps://www.aliexpress.com/item/1005009065662711.htmlTFT LCDOr, you can go the project way, and this RP2040 one is well documented.https://www.eevblog.com/forum/projects/pico-frequency-counter-using-rp2040/A RP2350 version of that should give better performance. I've not seen one yet ?

author: alex843
author_rank: Contributor
timestamp: August 26, 2025, 08:15:42 am
content: Quote from: mikeselectricstuff on May 27, 2025, 05:22:15 pm13 MHz is used in GSM base stations which makes sense in that application:* 13 MHz/48 = 270.83 kHz which is the GSM Air Interface bit rate/symbol rate.* 13 MHz/65 = 200 kHz, the GSM radio channel spacing.

author: 5U4GB
author_rank: Super Contributor
timestamp: August 26, 2025, 09:16:31 am
content: Quote from: PCB.Wiz on May 28, 2025, 05:49:09 amAlso a great source of stuff that's good-enough and where you don't fuss too much about the loss if someone uses it to, for example, check whether the mains frequency is exactly 50Hz.

author: mino-fm
author_rank: Regular Contributor
timestamp: August 26, 2025, 11:32:31 am
content: Quote from: Terry Bites on May 27, 2025, 04:13:44 pmThis one uses Vref = 12 MHzhttps://www.eevblog.com/forum/projects/pico-frequency-counter-using-rp2040/msg4151122/#msg4151122:-)

author: bingo600
author_rank: Super Contributor
timestamp: August 27, 2025, 02:04:36 pm
content: I have one of those Ali 2.7GHz counters that uses 13MHz - It has an Atmega inside.I had a few Pletronics 26MHz OCXO's in the drawer , and an AC74 .....Runs quite stable now.

author: dobsonr741
author_rank: Frequent Contributor
timestamp: August 30, 2025, 02:59:42 pm
content: Why 13 MHz?Because 26 MHz TCXOs are everywhere—thanks to cellphones. GSM, LTE, GPS… all tick to 26 MHz. And when Chinese makers whip up gadgets from bargain-bin parts, guess what crystal fell off the truck? Yep. Divide by two, call it 13 MHz.

author: Haenk
author_rank: Super Contributor
timestamp: August 30, 2025, 03:28:26 pm
content: Quote from: dobsonr741 on August 30, 2025, 02:59:42 pmAn that's bad, because?On the one hand suggesting to buy decade old gear, on the other hand refusing the re-use of precision parts. OK, they crystals certainly or most likely *are* reused and not declared as such. But I would guess these cheap chinese instruments are as precise as those old HP units, even with ovenized crystals.