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

[Scott Newell]

At 02:07 AM 3/13/2024, Wilko Bulte wrote:

>So, I would stay away from the Atom boards, the i3 and probably the 
>Xeons (are those server mainboards). Pick the i7 boards and try.

Good advice, it turns out!

The RX888 arrived Monday, but I didn't get to play with it until 
Tuesday. 64 MHz sample rate on the Xeon E5-1620 brought it to its 
knees. The i7-4790 seems ok at a 64 MHz sample rate (load avg 0.30, 
top shows 46% CPU) with a locally generated fftw wisdom file (but I 
do wonder if I should re-run it for 2 or 4 threads). Then again, I 
could be dropping samples left and right and I'm not sure I'd even know...

I ran a 50' wire from the window to the corner fencepost and now that 
the sun is down I'm getting decent reception on the WWV and CHU time 
stations. The ka9q-web app is a lot of fun!

Now I'm wondering how to GPS lock it. I understand there's a 
connector (U.FL?) on board for an external 27 MHz reference. If the 
Si5351 clocks the ADC and the software can program it, maybe it can 
be tricked into using a 10 MHz reference instead?


-- 
newell  N5TNL