Sources for calibration
I haven't seen them mentioned in the discussion about calibration, but there are three excellent time and frequency standard stations in the East Europe, namely the RWM stations.
They are at 4.996 MHz, 9.996 MHz and 14.996 MHz
Depending on the time of the day, one or another is easily receivable, at least here in Europe.
They use Caesium standards, so are accurate beyond any normal SWL or Ham needs.
They alternate periods of 1 pps, 10 pps, continuous carrier and silence.
I use them since many years for any calibration, when not willing to fire up the Rubidium standard.
73 Alberto I2PHD
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