chapi
Member
Does anyone know where I can purchase a receiver like the one in this site:
Thanks.
Thanks.
Does anyone know where I can purchase a receiver like the one in this site:
The whole idea of a TRF is that there is no frequency changer in the receiver to modify the received signal frequency - trying to receive directly from a satellite would be very tricky - the low noise amplifier frequency changer box right up at the dish is there for a reason!
"trying to receive directly from a satellite would be very tricky"
Any one knows what is the trick?
I prefer satellite, but any receiver which once connected to a scope will display the carrier wave from a distanced transmitter will do.
Chapi,
If you end goal is as a calibration refernce then you'll not get great results due to doppler shift caused by ionoshperic propagaion effects. You'd be way better off picking up a realitively inexpensive GPSDO.
Hi Bill, I'm the designer of the WWV TRF receiver being discussed, and I would like to make a few comments. With a GPSDO you really have no idea if its output is accurate or not since firmware and hardware is involved to generate the GPSDO output from the received GPS signals and unless the specific model of GPSDO you are using has had its output validated against a NIST traceable standard you really don't know if the output signal of your GPSDO is accurate or not even if it is very stable (hopefully the manufacturers of each model of GPSDO do in fact validate the output of their GPSDO against a NIST traceable standard). The beauty of the WWV TRF receiver is that there is no firmware or hardware frequency conversion involved, so the output of the WWV TRF receiver is directly traceable to NIST but the accuracy is dependent on doppler shift as you mentioned. Due to doppler shift the WWV TRF receiver accuracy is typically +/- 0.2 Hz or better during the middle of the day when the ionosphere is most stable versus at sunrise or sunset. Therefore if you are looking for a frequency refererence directly traceable to NIST the WWV TRF receiver fits the bill and there is no need to have it periodically checked against a NIST traceable frequency reference to make sure it's still working properly, etc. In reality I think GPSDO receivers are a great tool (and very accurate), but you are indeed trusting that it's designed properly in the first place to produce accurate results, and you are also trusting that it continues to function properly. Bottom line is if you are looking for a frequency reference directly traceable to NIST that's accurate to within 1 Hz, the WWV TRF receiver is hard to beat. 73, Don (wd8dsb)Chapi,
If you end goal is as a calibration refernce then you'll not get great results due to doppler shift caused by ionoshperic propagaion effects. You'd be way better off picking up a realitively inexpensive GPSDO.
Bill (WA8WG)