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Not very successfull with SDR - Advice

Posted: Sat Jun 03, 2017 7:01 am
by darrenyorston
I have an SDR dongle from NooElec with their "HAM It Up? Upconverter. My antenna is a roof mounted Diamond D-130.

I have tried using the dongle with and without the upconverter.

I have not been successful listening to much and would appreciate some advice. I have been able to find the commercial FM and AM radio stations the same as I can listen to in my vehicle. However, I have not been able to listen to anything else. I have the frequency for my local airport, approach, ground, departure and such, but SDR# doesnt show me any traffic on those frequencies. Also I have been unable to pick up any VHF Marine or UHF 466/477 traffic around me either.

I can get ADSB traffic via RTL1090 just no radio traffic.

Any advice would be much appreciated.

Re: Not very successfull with SDR - Advice

Posted: Sun Jun 04, 2017 3:40 pm
by Username
What kind of Antenna do you use?

Re: Not very successfull with SDR - Advice

Posted: Sun Jun 04, 2017 10:09 pm
by darrenyorston
Username wrote:What kind of Antenna do you use?
Diamond d-130 discone. The receiving range is 25 to 1300MHz

The oscilator offset on the ham it up is 120 000.

I have a held UHF, 476/477MHz, so i utilised that to check that my system is working. When i press the PTT the frequency showing on SDR# is incorrect. So i adjusted the oscillator offset so that the freq in SDR# matched the known UHF freq. This was 38 000. I dont know if this is correct, but it would seem logical that if i have a known signal output to use that as a calibration.

Re: Not very successfull with SDR - Advice

Posted: Sun Jun 04, 2017 10:13 pm
by Username
a ofset antenna have gain of quite 0db so you also need an LNA.
Do you set the frequency correction right in the SDR Dongle Menue?

Re: Not very successfull with SDR - Advice

Posted: Sun Jun 04, 2017 10:45 pm
by darrenyorston
Username wrote:a ofset antenna have gain of quite 0db so you also need an LNA.
Do you set the frequency correction right in the SDR Dongle Menue?
I don't know what you mean by "a offset antenna have gain of quite 0db so you also need an LNA."

The shift on the radio is set to 120 000, that is the offset printed on the Ham It Up, however as I mentioned the frequency is off when I use a known UHF source to transmit.

Re: Not very successfull with SDR - Advice

Posted: Sun Jun 04, 2017 11:31 pm
by rtlsdrblog
Are you remembering to set the RF gain manually?

Re: Not very successfull with SDR - Advice

Posted: Mon Jun 05, 2017 12:36 am
by darrenyorston
rtlsdrblog wrote:Are you remembering to set the RF gain manually?
I have RF Gain set at 22.9 dB. I have tried adjusting up and down but it doesn't appear to have much affect on what comms I can detect.

I have tried monitoring the UHF 476/477MHz and VHF Marine 156/157MHz frequencies but I don't hear any traffic.

FM and AM commercial radio channels are crystal clear. Yesterday I was also able to hear a 118MHz station broadcasting from New Zealand, I am in Australia, so I know the device is working.

It's likely a setup issue and use. I don't know if I have things set up correctly and am also utilising it correctly. I am only new to this. I have watched numerous videos on YouTube and thought I had everything set up correctly. I live nearby two quaries and am also under the civl aviation flight path so I am pretty confident there is radio traffic around me. Even when I have the comemrical aviation approach/departure freq for my local airport set and can observe an aircraft on departure I am not hearing any comms.

My antenna is on the roof of my house on a standard aerial J pole. I am on a slight hill so my house is above others nearby. My house is wooden framed with a terra cotta roof tile.

I have a Baofeng BF-F8HP handheld. When I connect it up to the discone through a Surecom SW-102 SWR meter and transmit I get an VSWR of 1.7.

Re: Not very successfull with SDR - Advice

Posted: Mon Jun 05, 2017 8:02 am
by Username
sorry I was to tiered.
I mean a Discone Antenna have mostly 0db Gain.
I use an cheap Ebay Discone to. In comparison with my cheap and crapy 400Mhz Antenna from Ebay the Discone is deb. :o
On my cheap 400mhz Antenna I receive 50% to 100% more!
I have a Baofeng BF-F8HP handheld.
knowen to have not the best receiving quality.

Re: Not very successfull with SDR - Advice

Posted: Mon Jun 05, 2017 8:38 am
by darrenyorston
Username wrote:sorry I was to tiered.
I mean a Discone Antenna have mostly 0db Gain.
I use an cheap Ebay Discone to. In comparison with my cheap and crapy 400Mhz Antenna from Ebay the Discone is deb. :o
On my cheap 400mhz Antenna I receive 50% to 100% more!
I have a Baofeng BF-F8HP handheld.
knowen to have not the best receiving quality.
Sure, but the Baofeng was simply used to test SWR.

I am more interested in whether it is an SDR# configuration issue. I input the 120 000 local oscilator shift as per what I have seen on a number of guides. When I utilise my handheld UHF to transmit on 477.100MHz SDR# shows the transmission on 477.182.256MHz. I am presuming this means that the offset I have set in the Radio tab is incorrect.

Re: Not very successfull with SDR - Advice

Posted: Mon Jun 05, 2017 8:48 am
by Username
sorry i dont understand what you do...

1) put everythink on default settings
2) search on google for your local weather channel from the next Airport.
for example Depature/ Arrival Information the transmit 24/7 an Automatic Audio Broadcast.
If you not have any try an Amateur Radio Repeater.

3) klick on the gear and a popo up with "rtl-sdr controller" show
un the bottom you see frecency correction.

4) if you have 2) enter the freq. of the channel and with up or down from the freq cor. callibrate your donge.
when you power it up wait 5 - 10 minutes until your dongle get worm.