Hi there, Dave. I'm not sure if this might help, but I purchased some extremely=20 inexpensive hand-held frequency counters several years back. These=20 are from China and offer two different modes of operation: continuous=20 carrier **OR** OOK reception. The menu calls that mode "Digital" and=20 it is intended to measure the frequency of OOK transmitters such as=20 car door unlock key fobs. I don't often use that mode but it does=20 seem to work. I can dig up one of those units and try to find a current listing if you ne= ed. Just a thought. dwayne At 06:37 AM 9/18/2019, David Van Horn wrote: >The transmitters are simple OOK, no modulation other than that. > >Unfortunately, all the software based approaches would take time=20 >that I don't have to create a locked down front end. >The pulses make it hard to use any sort of counter based approach. >Some beacons have diagnostic modes that will run continuous carrier,=20 >but not all. > >-- >David VanHorn >Lead Hardware Engineer > >Backcountry Access, Inc. >2820 Wilderness Pl, Unit H >Boulder, CO 80301 USA >phone: 303-417-1345 x110 >email: david.vanhorn@backcountryaccess.com > >-----Original Message----- >From: piclist-bounces@mit.edu On Behalf Of=20 >Forrest Christian (List Account) >Sent: Wednesday, September 18, 2019 1:43 AM >To: Microcontroller discussion list - Public. >Subject: Re: [EE] Simple spectrum analyzer > >I was also going to suggest the rtl-sdr based ones, but they=20 >apparently only go down to 500kHz. > >But I agree, there are lots of SDR's out there for not a lot of=20 >money, and most of them have open source spectrum analyzer tools=20 >which one could >modify to fit the 'ease of use' needs. You could conceivably provide a >USB dongle and a bundled piece of PC software which would do the=20 >spectrum analysis piece. > >If you're really bored you could probably include some data/protocol=20 >decoders as well if this is a data radio you're looking at..... > > > >On Tue, Sep 17, 2019 at 6:39 PM Brent Brown wrote: > > > David Van Horn wrote: > > > I need a recommendation for a simple SA, to be used by non-engineers. > > > Resolution of about 1Hz, and accuracy of 1ppM or less. > > > The frequency of interest is a 200 Hz slice around 457kHz > > > > Perhaps an SDR? PC can use preset config to hide all/most controls and > > just show what's required. I have one of the following, covers 1kHZ to > > 2GHz, basic accuracy 0.5ppm & trimmable, USD169: > > https://www.sdrplay.com/rsp2/ The RSP1A has fewer inputs but otherwise > > similar specs for USD109. > > > > Just for fun I tried it here, approx 456.9kHz signal with display > > centered on 457kHz. > > Attached image, if small enough to be make it through. The minimum > > sampling BW is 1MHz, so zoomed to the max only shows divisions of > > 10Hz... perhaps not quite the resolution you are looking for. > > > > -- > > http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive > > View/change your membership options at > > http://mailman.mit.edu/mailman/listinfo/piclist > > > > >-- >- Forrest >-- >http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive=20 >View/change your membership options at=20 >http://mailman.mit.edu/mailman/listinfo/piclist > >-- >http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive >View/change your membership options at >http://mailman.mit.edu/mailman/listinfo/piclist --=20 Dwayne Reid Trinity Electronics Systems Ltd Edmonton, AB, CANADA 780-489-3199 voice 780-487-6397 fax 888-489-3199 Toll Free www.trinity-electronics.com Custom Electronics Design and Manufacturing --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .