I have a question for the shortwave listeners on the board: can you hear a very bad-sounding 120 Hz hum, that sounds like a defective power supply filtering capacitor on WWV at 5.0 MHz? Can you hear the splatter around 4.950 MHz? The other WWV frequencies aren't experiencing this problem.
http://en.wikipedia.org/wiki/Inter-range_instrumentation_group_time_codes
http://en.wikipedia.org/wiki/WWV_(radio_station)#BCD_time_code
You might be hearing the IRIG format-H time code WWV transmits in-band on its audio signal. It sounds like a low 100Hz humming noise in the background, sometimes not even that far in the background.
I too have noticed lately that it is louder on 5000 kHz than on the other WWV frequencies. I think if NIST is deliberately running it louder on 5000 for some odd reason, it might be to overcome the BPL and computer hash noise (wild guess.)
Haven't checked out 4950 yet.
Yesterday, it sounded like the 100 Hz tone and the beeps were beating with the 120 Hz power ripple. The other WWV frequencies that were receivable at the time sounded clean, with the 100 Hz tone being barely audible (the shortwave radio I was using at the time has a bass-cut in the audio section that cannot be defeated).
Very strange ! From what I am hearing, I think the problem transmitter is WWV-H, it will be interesting to see if it gets worse later, when WWV-H gains a little more strength. I really do not hear anything strange on 4.950.
I thought I had read somewhere that WWV-H had shut down.
Apparently not!
http://en.wikipedia.org/wiki/WWVH
Skybill9:
You're thinking of CHU. They were scheduled to shut down on December 31, 2008, however they were able to move frequencies:
It was kinda a big deal last summer and they sent a few surveys out to see how popular the station was...
CHU:
"7335 kHz was moved to 7850"
THANK YOU ! preset on Icom has been changed!
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