|
Posted by Gedas W8BYA on January 07, 2026 at 16:37:25.
In Reply to: Re: JJY CW ID, Jan 6, 2026 posted by Bruce WA1HGJ on January 07, 2026 at 14:05:25.
|
FB Ed and Bruce ! Like you I can remember the 1st time I had a reception of DCF77, it was very exciting. And truth be told I still get a kick every time I hear it. FYI, you know you have red hot propagation to DCF77 when you start seeing, along with their main carrier signal, is a much weaker phase modulated signal on both sides of the carrier but reduced in amplitude by at least 25-30 dB. At first I thought it was a "dirty" transmitter on their end but it turns out they purposely send out a phase modulated signal for increased time accuracy. So if you see a hump directly around the carrier you know you have hit pay-dirt. Also since you mentioned hunting for other time stations have a listen for RBU in Moscow on 66.666 kHz. Best time to see/hear their carrier is an hour before your local SS continuing for the next 3-4 hours. At least that is what I have been seeing here in Indiana. You will see their main carrier and then a pair of sidebands +/- 100 Hz on each side, and then just a little further out a pair of very weak sidebands that carry the actual "ticking" audio. For the longest time I could not figure out why when I tuned right to the carrier and had a nice signal and in a 100-150 Hz BW I was hearing no tick marks. Only recently did I learn I needed to open up the bandpass to about 400 Hz or so to be able to get the entire signal. If you like I can post some audio and images of the DCF77 phase noise and the RBY time ticks, just let me know if you are interested. 73 Gedas W8BYA
|
Follow Ups:
|