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is this LW reception?

Posted: Mon Feb 11, 2019 11:46 am
by illllm
Am I receiving LW or is this an image?

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

Thanks !

Re: is this LW reception?

Posted: Tue Feb 12, 2019 2:10 am
by Mike2459
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

Re: is this LW reception?

Posted: Tue Feb 12, 2019 3:24 am
by Mike2459
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 3115 times


Port Hi-Z.JPG
Port Hi-Z.JPG (235.69 KiB) Viewed 3115 times

Re: is this LW reception?

Posted: Tue Feb 12, 2019 6:40 pm
by ON5HB
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%.

Re: is this LW reception?

Posted: Wed Feb 13, 2019 9:40 pm
by illllm
Yes I changed it to ZIF.

Re: is this LW reception?

Posted: Wed Feb 13, 2019 9:42 pm
by ON5HB
Does it help?

Re: is this LW reception?

Posted: Thu Feb 14, 2019 1:52 pm
by illllm
I does something, but I am not sure. i will capture a video and upload.

Re: is this LW reception?

Posted: Thu Feb 14, 2019 6:51 pm
by ON5HB
Also lower the RF-gain to about 50%.

Re: is this LW reception?

Posted: Mon Feb 18, 2019 11:29 pm
by Mike2459
HGA22 Lakihegy, Hungary - 2325Z (1825 local time)
HGA22.JPG
HGA22.JPG (58.76 KiB) Viewed 2697 times

Re: is this LW reception?

Posted: Tue Feb 19, 2019 12:55 pm
by ON5HB
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 2639 times
I have a signal 135.6