locked Curved Line in Waterfall


Brian Wilkins <bwilkins@...>
 

I was listening on 17m today. What causes this curved line in the waterfall?


 Link to picture

--
Brian Wilkins
KO4AQF


K8BL BOB LIDDY <k8bl@...>
 

Brian,

That was from a Space-X launch today.

Actually, it's a drifting carrier detected on the WSJTX Waterfall. You'll
see that often on various Bands. Also, you can often see a straight vertical
line from a solid carrier or an interrupted one from CW.

73,     Bob  K8BL

On Sunday, May 10, 2020, 12:17:53 PM EDT, Brian Wilkins <bwilkins@...> wrote:


I was listening on 17m today. What causes this curved line in the waterfall?


 Link to picture

--
Brian Wilkins
KO4AQF


 

Birdie drifting. 

On May 10, 2020, at 12:17, Brian Wilkins <bwilkins@...> wrote:


I was listening on 17m today. What causes this curved line in the waterfall?


 Link to picture

--
Brian Wilkins
KO4AQF


Brian Wilkins <bwilkins@...>
 


Bob

You had me at first. I live on the Space Coast and thought I missed one!

Thanks for the info


On Sun, May 10, 2020 at 12:29 PM K8BL BOB LIDDY <k8bl@...> wrote:
Brian,

That was from a Space-X launch today.

Actually, it's a drifting carrier detected on the WSJTX Waterfall. You'll
see that often on various Bands. Also, you can often see a straight vertical
line from a solid carrier or an interrupted one from CW.

73,     Bob  K8BL

On Sunday, May 10, 2020, 12:17:53 PM EDT, Brian Wilkins <bwilkins@...> wrote:


I was listening on 17m today. What causes this curved line in the waterfall?


 Link to picture

--
Brian Wilkins
KO4AQF

--
Brian Wilkins
KO4AQF


Dave (NK7Z)
 

Hi,

It looks like a carrier started at the bottom of your screen, (or you came upon it at that point), at around 1230 Hz, higher than your dial frequency, and over the period of one minute moved upwards in frequency. This assumes the graticule marks are 100 Hz apart, and 15 seconds apart on the vertical.

This could be pretty much anything, heater, thermostat, controller for stoves, etc... All you really know is some signal moved up in frequency across a one minute period.

73, and thanks,
Dave (NK7Z)
https://www.nk7z.net
ARRL Volunteer Examiner
ARRL Technical Specialist
ARRL Asst. Director, NW Division, Technical Resources

On 5/10/20 9:17 AM, Brian Wilkins wrote:
I was listening on 17m today. What causes this curved line in the waterfall?
 Link to picture
https://imgur.com/alQtCKV
--
Brian Wilkins
KO4AQF


Samuel W7STF
 

Has anyone else noticed some slight variation in received messages in WSJT-X well after warmup? I'm noting a little tilting, and I wonder if the radio is experiencing a little thermal drift. Is there a PC program to measure drift using  WWV as a calibrated source?Thx. Sam KJ4VPI


Bill Somerville
 

On 11/05/2020 12:58, Samuel KJ4VPI wrote:
Has anyone else noticed some slight variation in received messages in WSJT-X well after warmup? I'm noting a little tilting, and I wonder if the radio is experiencing a little thermal drift. Is there a PC program to measure drift using  WWV as a calibrated source?Thx. Sam KJ4VPI
Hi Sam,

you can use WSJT-X Frequency Calibration mode to measure your rig's frequency accuracy over time.

73
Bill
G4WJS.


Gary - AG0N
 

On May 11, 2020, at 05:58, Samuel KJ4VPI <sernstfortin@...> wrote:

Has anyone else noticed some slight variation in received messages in WSJT-X well after warmup? I'm noting a little tilting, and I wonder if the radio is experiencing a little thermal drift. Is there a PC program to measure drift using WWV as a calibrated source?
There’ll be those who say to use the Freq Cal mode, but you don’t even need that if you’re just looking for large drift. Take the VFO and shove it to your nearest friendly neighborhood WWV/CHU frequency, tune off center by 1000 or 1500 (whatever you want), and just leave it. If the radio is drifting, you should be able to see it right away. If it is a long term deal, park it for an hour, or hours, and see what it does over time. If you use the Freq Cal mode, it will read out the tone frequency in decimals of cycles so you can see precisely what it is doing.

Gary - AG0N


Gary - AG0N
 

On May 11, 2020, at 09:27, Gary - AG0N <mcduffie@...> wrote:



On May 11, 2020, at 05:58, Samuel KJ4VPI <sernstfortin@...> wrote:

Has anyone else noticed some slight variation in received messages in WSJT-X well after warmup? I'm noting a little tilting, and I wonder if the radio is experiencing a little thermal drift. Is there a PC program to measure drift using WWV as a calibrated source?
There’ll be those who say to use the Freq Cal mode, but you don’t even need that if you’re just looking for large drift. Take the VFO and shove it to your nearest friendly neighborhood WWV/CHU frequency, tune off center by 1000 or 1500 (whatever you want), and just leave it. If the radio is drifting, you should be able to see it right away. If it is a long term deal, park it for an hour, or hours, and see what it does over time. If you use the Freq Cal mode, it will read out the tone frequency in decimals of cycles so you can see precisely what it is doing.

By the way, drifting should not change anything WSJT-X presents to you in the form of a message. The only thing you should see WSJT-X do is show you a different DF each receive cycle for a given signal that is not really moving.

Gary


Dave (NK7Z)
 

Pretty much, if all the traces are tilted in the same direction, it is probably your radio drifting. If you have a few straight traces, and a pile of tilted traces, the radio is probably not drifting, but still a bit suspect...

Just watch things for a bit, if in the whole you are seeing all traces tilt, the radio is drifting.

I was seeing that now and then, I changed to a TXCO, and have not seen it again.

73, and thanks,
Dave (NK7Z)
https://www.nk7z.net
ARRL Volunteer Examiner
ARRL Technical Specialist
ARRL Asst. Director, NW Division, Technical Resources

On 5/11/20 8:27 AM, Gary - AG0N wrote:

On May 11, 2020, at 05:58, Samuel KJ4VPI <sernstfortin@...> wrote:

Has anyone else noticed some slight variation in received messages in WSJT-X well after warmup? I'm noting a little tilting, and I wonder if the radio is experiencing a little thermal drift. Is there a PC program to measure drift using WWV as a calibrated source?
There’ll be those who say to use the Freq Cal mode, but you don’t even need that if you’re just looking for large drift. Take the VFO and shove it to your nearest friendly neighborhood WWV/CHU frequency, tune off center by 1000 or 1500 (whatever you want), and just leave it. If the radio is drifting, you should be able to see it right away. If it is a long term deal, park it for an hour, or hours, and see what it does over time. If you use the Freq Cal mode, it will read out the tone frequency in decimals of cycles so you can see precisely what it is doing.
Gary - AG0N


Dave_G0WBX
 

Re:-

Is there a PC program to measure drift using WWV as a calibrated source?

Though WSJTx has some functionality, I've not seen anything in it to
calibrate for any sound card sample rate discrepancy.  (Unless I've just
not found it yet.)

However.  Fldigi has a frequency measuring and recording function.   It
also does allow you to correct for the sound card's "Actual" sample rate
against any of the usual broadcast Standard Frequency and Time stations.

73.

Dave G0WBX.


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