Unfamiliar signals in waterfall #FT8 #Waterfall


Kenneth Williams
 

I was wondering if anyone had a comment on what I might be looking at or what might be happening to result in this waterfall display.
Also, if you look at the graph at the bottom, it also looks strange, but consistent with the waterfall in terms of cumulative power vs fq.

This is from v2.4.0-rc1 on a 64-bit windows 7 machine operating FT8.

I don't think I've ever seen anything like this.

Thanks in advance for any comments or thoughts.

Ken
KC6PUQ





JP Tucson, AZ <samcat88az@...>
 

Hi Ken,

You mean the obviously over-powered transmission; splattering & spewing harmonics like a busted jet engine spitting parts numbers out with the exhaust?


Caption for attached image below: "well hell, there's your problem right there, you're missing a bunch of part numbers!"  

73 - John - N7GHZ


On Thu, Feb 11, 2021, 11:08 PM Kenneth Williams <ken.williams@...> wrote:
I was wondering if anyone had a comment on what I might be looking at or what might be happening to result in this waterfall display.
Also, if you look at the graph at the bottom, it also looks strange, but consistent with the waterfall in terms of cumulative power vs fq.

This is from v2.4.0-rc1 on a 64-bit windows 7 machine operating FT8.

I don't think I've ever seen anything like this.

Thanks in advance for any comments or thoughts.

Ken
KC6PUQ








Mike Lavelle K6ML
 

looks like a the signal at 400 Hz has a lot of harmonic distortion.  Each harmonic is wider aith more distinctly spaced tones.   Maybe one very strong signal from the hosue next door :)

Sent from Xfinity Connect App



------ Original Message ------

From: Kenneth Williams
To: main@WSJTX.groups.io
Sent: February 11, 2021 at 10:08 PM
Subject: [WSJTX] Unfamiliar signals in waterfall #FT8 #Waterfall

I was wondering if anyone had a comment on what I might be looking at or what might be happening to result in this waterfall display.
Also, if you look at the graph at the bottom, it also looks strange, but consistent with the waterfall in terms of cumulative power vs fq.

This is from v2.4.0-rc1 on a 64-bit windows 7 machine operating FT8.

I don't think I've ever seen anything like this.

Thanks in advance for any comments or thoughts.

Ken
KC6PUQ





Reino Talarmo
 

>I was wondering if anyone had a comment on what I might be looking at or what might be happening to result in this waterfall display.
Also, if you look at the graph at the bottom, it also looks strange, but consistent with the waterfall in terms of cumulative power vs fq.

This is from v2.4.0-rc1 on a 64-bit windows 7 machine operating FT8.

I don't think I've ever seen anything like this.

Thanks in advance for any comments or thoughts.

Ken
KC6PUQ

Hi Ken,

 

Thanks for an excellent example what WSJT-X operator should not do!
The operator has select TX (audio) frequency about 420 Hz and is heavily over-driving audio path, including modulator of his rig. Those fences are just multiples of 420 Hz!

This is the reason why Split should be used whenever supported by the rig.

 

73, Reino OH3mA


 

Ken,

 

It looks like the signal at ~370 Hz is well overdriving the audio stage, and generating AF harmonics. Each successive harmonic has the eight tones further apart.

 

73 Phil GM3ZZA.

 

Sent from Mail for Windows 10

 

From: Kenneth Williams
Sent: 12 February 2021 06:08
To: main@WSJTX.groups.io
Subject: [WSJTX] Unfamiliar signals in waterfall #FT8 #Waterfall

 

I was wondering if anyone had a comment on what I might be looking at or what might be happening to result in this waterfall display.
Also, if you look at the graph at the bottom, it also looks strange, but consistent with the waterfall in terms of cumulative power vs fq.

This is from v2.4.0-rc1 on a 64-bit windows 7 machine operating FT8.

I don't think I've ever seen anything like this.

Thanks in advance for any comments or thoughts.

Ken
KC6PUQ




 


--
73 Phil GM3ZZA


Keith Onishi
 

Those are children signal of the strong signal near the low edge.
Too much audio input to TRX at a sender may cause this.

Kiichiro (Keith) Onishi
Sent from iPad

2021/02/12 15:08、Kenneth Williams <ken.williams@gmail.com>のメール:

I was wondering if anyone had a comment on what I might be looking at or what might be happening to result in this waterfall display.
Also, if you look at the graph at the bottom, it also looks strange, but consistent with the waterfall in terms of cumulative power vs fq.

This is from v2.4.0-rc1 on a 64-bit windows 7 machine operating FT8.

I don't think I've ever seen anything like this.

Thanks in advance for any comments or thoughts.

Ken
KC6PUQ




<dummyfile.0.part>



Bill Somerville
 

On 12/02/2021 05:51, Kenneth Williams wrote:
I was wondering if anyone had a comment on what I might be looking at or what might be happening to result in this waterfall display.
Also, if you look at the graph at the bottom, it also looks strange, but consistent with the waterfall in terms of cumulative power vs fq.

This is from v2.4.0-rc1 on a 64-bit windows 7 machine operating FT8.

I don't think I've ever seen anything like this.

Thanks in advance for any comments or thoughts.

Ken
KC6PUQ
Hi Ken,

at first glance those look like typical audio harmonics generated by stations over-driving their transmitters modulator audio input. There are two particularly bad examples there. Note they could be generated at your end, and in this case I think that may be the case as every signal above a certain strength seems to be distorted. Make sure you do not have excess RF GAIN, e.g. if you have the AGC off then reduce the RF GAIN until your Rx audio is linear again. Also make sure your NB is disabled, they can cause distortion when there are strong signals in the Rx passband.

You can easily verify if the problem is at your end, simply tune your rig's Rx off by 500 Hz and see if the harmonic relationships change or just shift in frequency by the amount you shift frequency. A shift implies the problem is at the transmitting station, whereas if the harmonic spacings remain relative to your base frequency (signal offset times 2, times 3, time 4 etc.) then the problem is at your end.

73
Bill
G4WJS.


Bill Pence
 

The signal at the top that gets wider appears to be artifacts from the super strong signal at 400 hz.
Note they are at 800, 1200, 1600, 2000, & 2400 and are wider at each step.

I've seen the small signals showing near the bottom, but I do not know what those might be.


Kenneth Williams
 

Thanks for all of the responses.  I suppose that I should have known what this was but I did not and now I do.
I am going to pay particular interest to the comments from Bill S. because my first order of business is to keep my own house in order. I do have a neighbor that regularly gives me a +40 on my S meter and +26 in the band activity window and all I get on the waterfall is an extra-wide splotch of red without the extra stuff I see in this picture but we have had some rain here recently and I suppose that this could change the conductivity of the ground so nearby strong signals are having a different effect.

I will then take a look at my ALL.TXT file (finally, a use for that file) and see if I can identify the transmitter and go from there.  Don't tell me that none of you have ever had an 'oops' moment and set something incorrectly :).

Regards

Ken
KC6PUQ


Hasan Schiers N0AN
 

It looks like a Q65 mode , someone transmitted it by mistake
73, N0AN
Hasan


On Fri, Feb 12, 2021 at 12:08 AM Kenneth Williams <ken.williams@...> wrote:
I was wondering if anyone had a comment on what I might be looking at or what might be happening to result in this waterfall display.
Also, if you look at the graph at the bottom, it also looks strange, but consistent with the waterfall in terms of cumulative power vs fq.

This is from v2.4.0-rc1 on a 64-bit windows 7 machine operating FT8.

I don't think I've ever seen anything like this.

Thanks in advance for any comments or thoughts.

Ken
KC6PUQ