is this LW reception?

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illllm
Posts: 57
Joined: Wed Jan 23, 2019 10:26 pm

is this LW reception?

Post by illllm » Mon Feb 11, 2019 11:46 am

Am I receiving LW or is this an image?

https://www.youtube.com/watch?v=RLTUxC94LVA

Thanks !

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Mike2459
Posts: 318
Joined: Mon Jul 24, 2017 8:24 pm

Re: is this LW reception?

Post by Mike2459 » Tue Feb 12, 2019 2:10 am

The signal on 191khz sounds like an AM signal, there are no LW broadcasters currently on that freq, the BBC is on 198khz along with an NDB in Dixon NC. The signals that I heard from your recording below 191khz sounds like hams, heard 2 or 3 sending morse code and another sending 45.5 baud RTTY between 150 and 180khz. A good low pass filter that attenuates signals above 500khz would block these. Without my low pass filter connected I can hear hams and AM broadcast stations operating on MW and higher frequencies at 150 to 500 khz. Your MW/FM Notch filter should be attenuating those bands but they have no impact above 1700khz. I always use the Hi-Z port on frequencies below 30 Mhz, although it is susceptible to overloading, occasionally it is necessary to insert a 10db attenuator. I am getting the impression that your incoming RF is simply too strong and your RSP2 is being overloaded.

..more to folllow

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Mike2459
Posts: 318
Joined: Mon Jul 24, 2017 8:24 pm

Re: is this LW reception?

Post by Mike2459 » Tue Feb 12, 2019 3:24 am

As a test, I have my antenna connected to the A port. It's raining here so noise levels are higher. Here are 2 screenshots, the first is with Port A the second is HiZ. I can hear DIW in Dixon NC on both ports. For comparison, on A it is at -116.6 dbm with an SNR of 22 On the Hi-Z it is at -91.7dbm with a 24 SNR. I've made no other changes in settings to make this comparison. AGC was on manual at this time set to 30db, RF gain at maximum. The receiver was tuned to 198khz, DIW's carrier frequency. You can see the morse ID at about 1 khz above and below the carrier frequency in the screenshots.
Port A.JPG
Port A.JPG (224.68 KiB) Viewed 26886 times


Port Hi-Z.JPG
Port Hi-Z.JPG (235.69 KiB) Viewed 26886 times

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ON5HB
Posts: 140
Joined: Sat Dec 29, 2018 1:07 pm

Re: is this LW reception?

Post by ON5HB » Tue Feb 12, 2019 6:40 pm

Are you using Zero-IF mode? If not, that could solve the mixing problem.
Also, do not set RF-gain to maximum with SDR devices, if they overload ghost-signals appear.
Best is to stick at about 50%.

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illllm
Posts: 57
Joined: Wed Jan 23, 2019 10:26 pm

Re: is this LW reception?

Post by illllm » Wed Feb 13, 2019 9:40 pm

Yes I changed it to ZIF.

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ON5HB
Posts: 140
Joined: Sat Dec 29, 2018 1:07 pm

Re: is this LW reception?

Post by ON5HB » Wed Feb 13, 2019 9:42 pm

Does it help?

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illllm
Posts: 57
Joined: Wed Jan 23, 2019 10:26 pm

Re: is this LW reception?

Post by illllm » Thu Feb 14, 2019 1:52 pm

I does something, but I am not sure. i will capture a video and upload.

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ON5HB
Posts: 140
Joined: Sat Dec 29, 2018 1:07 pm

Re: is this LW reception?

Post by ON5HB » Thu Feb 14, 2019 6:51 pm

Also lower the RF-gain to about 50%.

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Mike2459
Posts: 318
Joined: Mon Jul 24, 2017 8:24 pm

Re: is this LW reception?

Post by Mike2459 » Mon Feb 18, 2019 11:29 pm

HGA22 Lakihegy, Hungary - 2325Z (1825 local time)
HGA22.JPG
HGA22.JPG (58.76 KiB) Viewed 26468 times

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ON5HB
Posts: 140
Joined: Sat Dec 29, 2018 1:07 pm

Re: is this LW reception?

Post by ON5HB » Tue Feb 19, 2019 12:55 pm

You are missing something.
Schermafdruk op 2019-02-19 13-53-54.png
Schermafdruk op 2019-02-19 13-53-54.png (85.95 KiB) Viewed 26410 times
I have a signal 135.6

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