[time-nuts] Re: SDR radios - Loran-C & WWV

[Jacob Bingham]

Hello, I recently joined this mailing list but I don't think I have said
anything yet :)

I don't know what kind of SDR you are referring to, but if your goal is
time synchronization (or even some coarse positioning), a cheap RTL-SDR
with a Bias tee is actually capable of receiving GPS(+QZSS), which in
theory is more accurate than LORAN and stations such as WWVB and WWV, since
meter-level precision fixes are on the order of nanosecond-precision.

The cheapest RTL-SDRs with Bias tees (and aren't clones or being resold or
anything) are the Nooelec NESDR SMArTee v2 and the RTL-SDR Blog V3 for the
same price as each other ($33.95), the Nooelec one allegedly has a 0.5 ppm
TCXO, while the RTL-SDR Blog one allegedly has a 1 ppm TCXO, however the
Nooelec one doesn't have direct HF sampling (if I understand their listing
correctly).

As for SMA active GPS patch antennas, there is no shortage of listings
online, however I personally have the "GNSS antenna square for
GPS/GLONASS/Beidou/Galileo" ("AN_GPS_A236") from "Suzhou Maswell
Communication Technology Co. Ltd" ("Maswell") which has
GPS+GLONASS+BeiDou+Galileo L1/E1 (and overlaps with some Iridium stuff if
you want to experiment with that too), allegedly IP67, and appears to be
selling right now for $28.