The transmitters are simple OOK, no modulation other than that.=20 Unfortunately, all the software based approaches would take time that I don= 't have to create a locked down front end.=20 The pulses make it hard to use any sort of counter based approach. Some beacons have diagnostic modes that will run continuous carrier, but no= t all. -- David VanHorn Lead Hardware Engineer Backcountry Access, Inc. 2820 Wilderness Pl, Unit H Boulder, CO =A080301 USA phone:=A0303-417-1345 =A0x110 email:=A0david.vanhorn@backcountryaccess.com=A0 -----Original Message----- From: piclist-bounces@mit.edu On Behalf Of Forres= t 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 apparently onl= y go down to 500kHz. But I agree, there are lots of SDR's out there for not a lot of money, and = most of them have open source spectrum analyzer tools 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 spectrum a= nalysis piece. If you're really bored you could probably include some data/protocol decode= rs 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=20 > just show what's required. I have one of the following, covers 1kHZ to=20 > 2GHz, basic accuracy 0.5ppm & trimmable, USD169:=20 > https://www.sdrplay.com/rsp2/ The RSP1A has fewer inputs but otherwise=20 > similar specs for USD109. > > Just for fun I tried it here, approx 456.9kHz signal with display=20 > centered on 457kHz. > Attached image, if small enough to be make it through. The minimum=20 > sampling BW is 1MHz, so zoomed to the max only shows divisions of=20 > 10Hz... perhaps not quite the resolution you are looking for. > > -- > 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 > -- - Forrest -- http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/chang= e your membership options at http://mailman.mit.edu/mailman/listinfo/piclis= t --=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 .