Author Topic: WXtoImg, funky lines  (Read 821 times)

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Offline Psynosaur

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WXtoImg, funky lines
« on: February 01, 2017, 01:04:11 PM »
Hi

I've searched through the forum but I cannot find a solution to the slight banding issue I am having with WXtoImg.

I'm using an Airspy and SDR-Console V3 to record passes and I pipe the audio to WXtoImg.

I am very happy with the images, I am just wondering if there is a common fix to this particular issue?

Sampling rates are 48KHz from SDR-Console to VB-AudioCable and out 48KHz to WXtoImg.

BW is 35KHz.

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Thanks in advance

Offline DanS

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Re: WXtoImg, funky lines
« Reply #1 on: February 01, 2017, 02:45:48 PM »
What kind of antenna are you using? Cable type and length makes a difference too.

Offline Psynosaur

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Re: WXtoImg, funky lines
« Reply #2 on: February 01, 2017, 02:51:52 PM »
Homemade copper pipe QFH 0.44 ratio -> LNA4ALL -> 12m of RG6 dual shielded cable ->  fm trap -> airspy

Thanks

[Edit] mounted outside on a mast about 8m form the ground
« Last Edit: February 01, 2017, 02:54:49 PM by Psynosaur »

Offline DanS

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Re: WXtoImg, funky lines
« Reply #3 on: February 01, 2017, 03:06:51 PM »
Maybe the LNA's power supply has noise?

Offline Psynosaur

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Re: WXtoImg, funky lines
« Reply #4 on: February 01, 2017, 03:26:37 PM »
Its powered via the airspy bias tee. I will remove the LNA tomorrow from my chain and see if that makes a difference.

Thanks Dan

Offline DanS

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Re: WXtoImg, funky lines
« Reply #5 on: February 01, 2017, 05:28:08 PM »
 ... or maybe a PC grounding (or lack of) issue?

Offline Psynosaur

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Re: WXtoImg, funky lines
« Reply #6 on: February 02, 2017, 06:37:01 AM »
Good morning

I removed the LNA and the problem persists.

I will now check for ground on my PC by using my laptop in the roof with a NOAA 19 pass.

This would cut out the patch cable I have running to my computer.

Offline Psynosaur

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Re: WXtoImg, funky lines
« Reply #7 on: February 02, 2017, 10:36:33 AM »
argh...

the culprit is my gaming monitor... It generates these moving noise columns :(

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Pretty terrible, the solution is to put the brightness down pass 80 cd/m2 then it completely solves the issue.

NOAA 15 pass next  \:D/

Offline DanS

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Re: WXtoImg, funky lines
« Reply #8 on: February 02, 2017, 04:46:28 PM »
wow, who would of thought. The PC's monitor generates noise spikes that are induced into the recording going to WxtoImg. Hmmm, have to keep that in mind.

Offline W3DRM

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Re: WXtoImg, funky lines
« Reply #9 on: February 03, 2017, 12:32:33 AM »
You might try some clamp-on ferrite filters to the power line and/or the video cable going to the monitor. They may help to block or reduce the interference.
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Offline Josiah

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Re: WXtoImg, funky lines
« Reply #10 on: February 07, 2017, 12:28:38 PM »
You might try some clamp-on ferrite filters to the power line and/or the video cable going to the monitor. They may help to block or reduce the interference.

You might also want to consider electrically bonding your equipment.

 

anything