locked Vertical spikes every 1000 hz prevent decoding
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Alan G4ZFQ
I was unable to measure the noise floor on my calibrated ANAN 7000DKE MKII -- it runs around -143dB and that's just too small to register on the ADC. I can increase the gain but that is a bogus measurement. Increasing the gain the lowest level SpectrumLab shows is around -130dB.Mike, Seems to me there are unknowns. Soundcards have different ADCs, gains, input noise. Essentially standards are required. I'm no expert but I'd attempt to test the SNR of a weakish standard. It may be necessary to play with gains. Then the resulting dynamic range is important. SpectrumLab is as good a tool to do this as any other but I don't think a single check on different cards without a standard will prove anything. 73 Alan G4ZFQ.
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Michael Black
I was unable to measure the noise floor on my calibrated ANAN 7000DKE MKII -- it runs around -143dB and that's just too small to register on the ADC. I can increase the gain but that is a bogus measurement. Increasing the gain the lowest level SpectrumLab shows is around -130dB. So it would appear to me that SpectrumLab is unable to measure the real noise floor. Mike W9MDB
On Friday, July 16, 2021, 05:56:10 AM CDT, bobo7493 via groups.io <bobo7493@...> wrote:
Hi Jan, i had also found a good program for testing the noise Level on USB Soundcards , there also some noise tests from some cheap usb soundcards on this side : https://dl1gkk.com/sound-card-check/ Hans / DB5ZP
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Michael Black
You can't measure noise floor this way. You have no idea what level those sound devices are representing as none of them are calibrated except your rig which is still doubtful. You need a reference signal so you can calibrate each device to a known source before you measure noise floor. So say a -70dB signal shows -70dB on the spectrum (assuming high resolution spectrum -- if it's a curve the power is integrated under the peak curve). You need at least two reference points to ensure linearity too. So measure -70dB then check below that and above it to see if it's linear. I can do that here with a 2 Signalinks and a couple of rigs and a signal generator. I'll do that and post the results using the same Spectrum Lab settings. Mike W9MDB
On Friday, July 16, 2021, 06:23:45 AM CDT, bobo7493 via groups.io <bobo7493@...> wrote:
[Edited Message Follows] Hi Jan,i had also found a good program for testing the noise Level on USB Soundcards "DL4YHF Audio Spectrum Analyzer" https://www.qsl.net/dl4yhf/spectra1.html There also some noise tests from some cheap usb soundcards on this side - tested with this program and how to use it for that...
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Hi Jan,
i had also found a good program for testing the noise Level on USB Soundcards "DL4YHF Audio Spectrum Analyzer" https://www.qsl.net/dl4yhf/spectra1.html There also some noise tests from some cheap usb soundcards on this side - tested with this program and how to use it for that... https://dl1gkk.com/sound-card-check/ Hans / DB5ZP
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USB has a synchronising pattern of bits every 1 ms. Also every 125 us for higher speed USB. I had this problem with one USB cable and I replaced it with a shorter shielded cable.
73 Phil GM3ZZA.
Sent from Mail for Windows 10
From: pa3abk
Sent: 15 July 2021 17:13 To: main@WSJTX.groups.io Subject: Re: [WSJTX] Vertical spikes every 1000 hz prevent decoding
Thanks OP for starting this... I was struggling with this problem with a cheap USB soundcard from Ali Express. Type 5HV2 it has a ferrite in it's lead and this should be a warning when buying... it has an interference issue. In AUDACITY you can make a frequency analyse which confirms this product is completely useless for our use. (For gaming it will work.)
-- 73 Phil GM3ZZA
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pa3abk
Thanks OP for starting this... I was struggling with this problem with a cheap USB soundcard from Ali Express. Type 5HV2 it has a ferrite in it's lead and this should be a warning when buying... it has an interference issue. In AUDACITY you can make a frequency analyse which confirms this product is completely useless for our use. (For gaming it will work.)
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bobo7493@...
I forgot..
I prefer to set the RC-Filter values on the 5 Volt USB Power to 10 Ohms and 100uF which will give you a cut-off Frequency at 159 hz and a maximum attenuation at 1 khz from around -90 db ! There are exist serveral "entry" USB soundcard Chips / sticks from CMEDIA on the market. The most chipsets are CM108, CM119, HS-100B. Also i prefer to take a cheap USB Stick which have the HS-100B inside. The HS-100B has the newest design - the CM chips are mouch older... Here is a good Youtube Video about Test with some cheap USB soundcards (sorry its in german), but you can maybe take a try on the pictures. 3D USB SOUNDCARD has the CM108 inside ... SABRENT USB SOUNDCARD has the HS-100B inside.. https://youtu.be/7hBjq6hZBrg 73 , Hans DB5ZP
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bobo7493@...
The problem is the poor 5V USB Power. Cheap USB soundcards missing filtering for that.
A lot from these chips comes from https://www.cmedia.com.tw also use google search for : usb noise 1khz you will find a lot about that. For a workaround - refer to this FAQ : https://www.cmedia.com.tw/support/faq Point 10 : Why does the Mic Record file with 1kHz Noise?
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The high speed and full speed modes have a sync pulse every 125us. Phil.
On 10 Oct 2020 19:40, Andy TALBOT <andy.g4jnt@...> wrote:
--
73 Phil GM3ZZA
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JP Tucson, AZ
Hmmm... If they are 50-70 dB down... you shouldn't see them at all if you have it setup right. Mine barely shows anything at all @ the bottom -25dB limit. Besides that, those images posted earlier showed very strong; i.e. red marks. 73 - John - N7GHZ
On Sat, Oct 10, 2020, 11:40 AM Andy TALBOT <andy.g4jnt@...> wrote:
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Andy Talbot
I see weak 1kHz spikes on every USB soundcard I've used (admittedly, most based around PCM2900 chips) Never really thought much of it, as they're typical 50 - 70dB below full scale. Interesting to know it may be USB sync, Andy
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On 09/10/2020 22:22, Joe KN5Y via groups.io wrote:
Seen in v2.2.2.Hi Joe, one thing you should always do when the waterfall looks wrong, uncheck the "Flatten" option. Flatten can produce strange artefacts when the audio source has very low amplitude, or a different bandwidth from what the waterfall is set for. It may become obvious what is wrong when you see the un-flattened waterfall and spectrum. 73 Bill G4WJS.
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I know it’s a bit after the event, but that looks like the sync pulse (1 or 2 data-bits wide every 1 ms) on one of modes of USB (low-speed, I think – mice, keyboards etc.). It’s too spot on 1 kHz spacing to be an SMPS.
73 Phil GM3ZZA
Sent from Mail for Windows 10
From: Joe KN5Y via groups.io
Sent: 10 October 2020 00:59 To: main@wsjtx.groups.io Subject: Re: [WSJTX] Vertical spikes every 1000 hz prevent decoding
Thanks to all the responses. I reset the sound control in the Windows 10 PC. Deselected the Audio options in WSJT-X 2,2,0-fc1, and got rid of the spikes. The Ft-991A is decoding up a storm. See ya down the log... 73, Joe Kn5y
-- 73 Phil GM3ZZA
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Joe KN5Y
Thanks to all the responses. I reset the sound control in the Windows 10 PC. Deselected the Audio options in WSJT-X 2,2,0-fc1, and got rid of the spikes. The Ft-991A is decoding up a storm.
toggle quoted messageShow quoted text
See ya down the log... 73, Joe Kn5y
On Oct 9, 2020, at 17:29, Istvan Nyul <inyul@...> wrote:
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I agree with John, this is what I see with the antenna switched to ground. No signals or band noise present, so the AGC increases the receiver gain to high and you start seeing phantom traces like this.
Check your connectors, and then try tuning up and down the band for CW & SSB signals. Are you hearing what you'd expect? 73 de Tim WA5MD, Dallas
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Istvan Nyul
I have seen the same kind of spikes when my RSPDuo was turned on, next to my rig and computer. 73, Steve - VE3USP
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M0PWX
i get signals like that with my work
laptop and monitors on
it is interference (fairly certain from
a pooly shielded switched mode PSU in the monitor)
on 40mtr tonight loads of traffic,
switch to 15mtr and i get similar lines and no decodes, as there
is no traffic being recieved on 15mtr at my location (i do get
decodes on 15mtr's at other times so i know the antenna works on
that band)
do you get decodes on other bands?, if
yes then you have the correct settings, if no check youre audio
input settings (line out from rig, correct audio card selected and
microphone levels high enough)
peter
 On Fri, 09/10/2020 23:06, Joe KN5Y via
groups.io wrote:
Wondering where the spikes come from? How to remove them?
This email has been scanned by iomartcloud. http://www.iomartcloud.com
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JP Tucson, AZ
The power supply most likely, especially if you use a switching supply. 73 - John - N7GHZ
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Joe WB9SBD
myself I would not even worry
about them, They are taking up less than 1% of the band, not
hurting anything at all.
toggle quoted messageShow quoted text
Joe WB9SBD On 10/9/2020 5:06 PM, Joe KN5Y via
groups.io wrote:
Wondering where the spikes come from? How to remove them?
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Joe KN5Y
Wondering where the spikes come from? How to remove them?
toggle quoted messageShow quoted text
They are high amplitude and periodic (every 1000 Hz) Regards, Joe KN5Y
On Oct 9, 2020, at 16:54, JP Tucson, AZ <samcat88az@...> wrote:
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