Re: SoftRock + WSPR
- Thanks Graham for the explanation. Given that second level time sync is only required, the likes of Dimension-4 or many other simple time sync applications should be fine. No need for NTPD IMHO. I need to learn more about WSPR and other small signal protocols/techniques.
--- In email@example.com, "grahamg3zod" <grahamg3zod@...> wrote:
> WSPR transmissions take place on even numbered UTC minutes and last for around 1 minute 51 seconds. That's why PC clocks need to be set reasonably accurately to UTC. However, around +/- half a second is more than adequate as the software will synchronize itself to incoming signals to within a few seconds.
> Windows XP/Vista don't actually need any external software for clock synchronization; the registry can be modified to change the default synchronization period to whatever is appropriate for the particular computer's clock creep. However, on XP the firewall needs to be set up to allow access to the NTP port and additionally not everyone may feel comfortable changing the registry.
> I'm happy just to let XP get on with it, but the Windows time synchronization is pretty minimalistic and many users will find it easier to install third party software. I'd rather not introduce more software / services than necessary though.
> 73 de Graham G3ZOD FISTS #8385
> --- In firstname.lastname@example.org, "drmail377" <drmail377@> wrote:
> > Why is the PC's clock an issue with WSPR? Is it accuracy or stability or both that is a problem?
> > Why install Dimension 4 (link http://www.thinkman.com/dimension4/)? I would think NTPD would work much better; it is the "gold" standard. NTPD is free, Dimension 4 is not. NTPD is typically installed by default by most Linux/Unix distributions (with the exception of OpenBSD, see below). A Precompiled Windows NTPD binary installer is freely available here:
> > http://www.meinberg.de/english/sw/ntp.htm
> > When I speak of NTPD I'm referring to the "real" NTPD from Dr. David Mills of the University of Delaware, not OpenNTPD which is part of the OpenBSD project. I find NTPD to be superior to OpenNTPD, but it is my opinion only.
> > NTPD is quite sophisticated and therefore a bit harder to set-up though. But it is worth it if disciplining the PC's clock is truly necessary for WSPR operation - which I question. I've never used WSPR though, so I'm certainly no expert.
> > With NTPD, if you have a GPS receiver with NMEA serial output and 1-PPS output, you can GPS discipline your PC via the an RS-232 serial port...
(Graham, not wishing to tread on your toes !)
I had a problem the other day when I was only RX’ing half of the stations I could “hear” correctly, then I realised that I had not updated my PC clock prior to WSPR use. What I think may have happened is that some stations were transmitting slightly out of time sync and my station was wrong in the opposite direction, time wise, thus not being able to decode them within the WSPR tolerance. The problem vanished as soon as I updated the PC clock. Being new to WSPR I was puzzled for a while, still, the wonderful thing about radio is you learn something new every day. I now have dimension 4 running.
While I am posting: I would like to add my thanks to Tony KB9YIG for the great job in providing kits. I have an RX 9 and am waiting for the RXTX special situation: Tony, take your time, we all appreciate your efforts.
73 de Roger G7RUH
PS, I am looking forward to a torroid time doing all that winding !