Good morning Luis, i agree and i had success just with my FT-857 as receiver which is not GPS stabilized (just a TCXO-9 installed). The only challenge was to find out the exact frequency offset. Easily I compared a couple of OP32 decodes with the result of the Grabber from Markus, DF6NM. So setup is Miniwhip, G0MRF LF preamp, FT857 feeding soundcard EMU-0202 where the right channel get 1pps signal from my 10MHz ref. Not a very sensitive receiving setup, but good enough to decode several stations in EBnaut up to VO1NA. Which you all a nice Christmas time and hny vy73 Marco DD7PC Von: owner-rsgb_lf_group@blacksheep.org [mailto:owner-rsgb_lf_group@blacksheep.org] Im Auftrag von VIGILANT Luis Fernández
Gesendet: Mittwoch, 19. Dezember 2018 07:39
An: rsgb_lf_group@blacksheep.org
Betreff: Re: LF: Ebnaut receiver frequency stability qustion I think that using expensive receivers is NOT the way to go. I'm using a simple mixer as downconverter. The LO is 120KHz generated from a uBlox GPS. So the 137KHz outputs as 17KHz and can be feeded to PC soundcard. The second channel of GPS provides 1pps to discipline the soundcard using Spectrum lab Not using filters at all and no amplifier stages. So there is room for improvement, but it works EA5DOM El 19 dic. 2018 1:33, Markus Vester <markusvester@aol.com> escribió: Hi Chris,
Kiwi-SDR: Last year I asked the same question to John Seamons, and he explained that the GPS frequency correction is done in software, and won't actually lock the LO phase to GPS.
RSP2: It seems possible to replace the TXCO by an external 24 MHz reference. But the difficulty with the digital output is that you need to be sure that buffer over/underruns never occur in the subsequent audio processing. With an analog receiver, SpecLab can correct glitches when you feed a 1pps time reference to the other soundcard channel. Unfortunately you can't do that with an all-digital audio path.
73, Markus
-----Ursprüngliche Mitteilung-----
Von: Chris Wilson <dead.fets@gmail.com>
An: rsgb_lf_group@blacksheep.org <rsgb_lf_group@blacksheep.org>; rsgb-lf-group@groups.io <rsgb-lf-group@groups.io>; Discussion of the Lowfer (US, European, & UK) and MedFer bands <lowfer@mailman.qth.net>
Verschickt: Di, 18. Dez 2018 23:54
Betreff: LF: Ebnaut receiver frequency stability qustion Would a KiwiSDR (which I do not own but was thinking of buying) have adequate LF frequency stability for Ebnaut reception given it uses 1PPS from a GPS receiver to stabilize the frequency? Or do I need a receiver with a true GPS trained reference input? I see only one cheaper price end RX with such a port, the SDRPlay RSP2, but that expects a 24 MHz reference input rather than the common 10 MHz. I have a Trimble Thunderbolt for a 10 MHz reference, but nothing that What commercial SDR's could I look to for suitable stability please, that are good on LF and below, and a reasonable cost? Thanks 2E0ILY
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