[time-nuts] WWVB: measuring local 60 KHz noise

On 5/6/2018 6:39 AM, Charles Steinmetz wrote: So, yes, a sound card designed for signals up to ~22kHz should handle SAQ at ~17kHz, but sound cards that can digitize signals above 22kHz are rare. Some "professional" sound cards handle signal frequencies up to ~40kHz, but very, very few handle

Re: [time-nuts] WWVB: measuring local 60 KHz noise

Long ago I did some WWVB signal-to-noise measurements with an HP 3586C selective voltmeter (commonly used by the FMT-nuts).  I measured the signal power at 60.0 kHz with 20 Hz bandwidth.  Then I measured the power a small offset plus and minus  (100 Hz?  I don't recall), and took the mean of

Re: [time-nuts] WWVB: measuring local 60 KHz noise

Hi First off, I don’t think there *is* an ideal antenna that “just works”. Maybe a proper set of EMAG probes that come with calibration sheets come close. For a home built this or that …. there are a lot of variables. First up is very much part of receiving WWVB in the first place. Coax to

Re: [time-nuts] WWVB: measuring local 60 KHz noise

Hi Hal: You might want to check the orientation and location of the antenna before digging into more technical areas. It's been my experience there's a lot of AC mains conducted noise at 60 kHz. http://www.prc68.com/I/LF-Ant.shtml#Noise http://www.prc68.com/I/Spec_0002.shtml - 0 to 200 kHz

Re: [time-nuts] WWVB: measuring local 60 KHz noise

Hal wrote: I assume the problem is noise. Is there any simple way to measure the noise around 60 KHz? How about not so simple? Extra credit for a way that others nuts can reproduce so we can compare the noise at my location with other locations. For any location near a city, the noise

Re: [time-nuts] WWVB: measuring local 60 KHz noise

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Re: [time-nuts] WWVB: measuring local 60 KHz noise

Alberto wrote: If you have a sound card capable of sampling at 192 kS/s, you don't need an SDR to receive a signal at 60 kHz... just connect the output of an active antenna, like e.g. the mini-whip, directly to the Line-In of the sound card * * * I used this method in the past to

Re: [time-nuts] WWVB: measuring local 60 KHz noise

Hi The sample rate on a sound card is not always a good indication of it’s performance. Some 192 KS/s cards have cutoff’s below 50 KHz. Others have a noise spectrum that rises quite a bit past 30 or 40 KHz. Lots to dig into …. Bob > On May 5, 2018, at 5:42 PM, Alberto di Bene

Re: [time-nuts] WWVB: measuring local 60 KHz noise

If you have a sound card capable of sampling at 192 kS/s, you don't need an SDR to receive a signal at 60 kHz... just connect the output of an active antenna, like e.g. the mini-whip, directly to the Line-In of the sound card, then use, for example, HDSDR as software, setting the sampling

Re: [time-nuts] WWVB: measuring local 60 KHz noise

Alex- how many turns on that loop? Dana On Sat, May 5, 2018 at 2:35 PM, Alexander Pummer wrote: > tuned,[ fine-tuning with vari-caps remotely] large size frame antenna 1 > meter dia provides mV size 60kHz in the Livermore area in California from > the Colorado WWVB TX > 73 >

Re: [time-nuts] WWVB: measuring local 60 KHz noise

tuned,[ fine-tuning with vari-caps remotely] large size frame antenna 1 meter dia provides mV size 60kHz in the Livermore area in California from the Colorado WWVB TX 73 KJ6UHN Alex On 5/5/2018 6:17 AM, Ulrich Rohde via time-nuts wrote: I am trying to use the 60 KHz for synchronization of a

[time-nuts] WWVB: measuring local 60 KHz noise

I have found the proximity of my home computer has kept a bedroom projection clock from locking to WWVB. Apparently the noise radiation from the computer effectively jams the 60 kHz signal. By setting the clock out on a deck about 30 feet further away from the computer, the clock locks up

[time-nuts] WWVB: measuring local 60 KHz noise

I have found the proximity of my home computer has kept a bedroom projection clock from locking to WWVB. Apparently the noise radiation from the computer effectively jams the 60 kHz signal. By setting the clock out on a deck about 30 feet further away from the computer, the clock locks up

Re: [time-nuts] WWVB: measuring local 60 KHz noise

Hi If you want delay ( hardware delay and not propagation), calibrating a SDR should not be to nutty. Some boards ( the Lime SDR comes to mind) will generate a signal as well as receive one. That could be piped into a scope to make the measurement fairly easy. Once you know what is going into

[time-nuts] WWVB: measuring local 60 KHz noise

Although it does not measure propagation delays, Lady Heather can now estimate propagation delays. You can enter the lat/lon/alt of the station or specify the station name. You can enter the ionosphere height, or Heather will estimate it depending upon the month. --- >

Re: [time-nuts] WWVB: measuring local 60 KHz noise

Hal, Some SDRs can tune that low and should provide a means to determine if noise is really the problem as well as give some clues as to the character of said noise. But they are much less likely to help with delay determination, unless you can figure out a practical way to ascertain the latency

Re: [time-nuts] WWVB: measuring local 60 KHz noise

Hi Even if you get the 60 KHz process working, a $20 GPS module ( or maybe $50) will do a much better job. That’s not saying *don’t* do the WWVB stuff. Just realize it’s limitations. A second limitation is that the new phase modulation process makes comparison a bit more complex. 60 KHz

Re: [time-nuts] WWVB: measuring local 60 KHz noise

contact me off list I have a couple   Bert Kehren   In a message dated 5/5/2018 9:17:45 AM Eastern Standard Time, time-nuts@febo.com writes:     I am trying to use the 60 KHz for synchronization of a Rb receiver. The local NJ noise and the signal in dBuV are about the same with an active

Re: [time-nuts] WWVB: measuring local 60 KHz noise

  I am trying to use the 60 KHz for synchronization of a Rb receiver. The local NJ noise and the signal in dBuV are about the same with an active antenna, electric field.  A better solution might be a ferrite selective antenna, H field , if I find one.   73 de N1UL      In a message dated

[time-nuts] WWVB: measuring local 60 KHz noise

Review/background: I have an UltraLink 333 WWVB receiver. It didn't work. Several weeks ago. a discussion here mentioned that the phone cable between the main box and antenna needs to be straight through rather than the typical reversed. That was my problem. With the correct cable, the