Search found 196 matches

by snn47
Tue Jan 14, 2020 5:51 pm
Forum: Antennas
Topic: Balum and Unun
Replies: 3
Views: 177

BALUN and Unun

Have you read the information provided here? https://www.rtl-sdr.com/forum/viewtopic.php?f=6&t=4649&p=10992&hilit=BALUN#p10948 antenna and cable can be symetrical e.g. dipole or parallel wire cable and asymetrical e.g groundplane and coax cable. A Balun adopts symetrical devices to a or unsymetrical...
by snn47
Tue Dec 31, 2019 2:38 am
Forum: Signal Identification Help
Topic: Schedules ?
Replies: 2
Views: 1144

Re: Schedules ?

It varies/depends on the weather services in your area, if, when and how often they launch weather ballons that transmitt weather data. Have you tried asking them politely and they may tell you (or choose not to)? Or you can do search and maybe find the information for your area Adelaide e.g. here h...
by snn47
Tue Dec 31, 2019 2:24 am
Forum: KerberosSDR
Topic: Locate Tetra radios/transmitters - help
Replies: 5
Views: 477

Direction finding vs. locating transmitters

Hello Jompa, How accurate dou you want to be? I'll try to explain the different options as I know them Direction finding (DF) requires at minimum 1 receiver and a (highly) rotateable directional Antenna, and provide the direction towards the transmitter from the antenna direction, but no distance, u...
by snn47
Mon Dec 23, 2019 6:52 am
Forum: Antennas
Topic: DIY suggestions for 120-130Mhz AM
Replies: 1
Views: 400

Re: DIY suggestions for 120-130Mhz AM

Are you on the top floor or do you have another balcony above you? If yes this will significantly influence antenna pattern and I would opt for a 1/4 wave ground plane with thick tubing to increase bandwidth. Any antenna with higher gain will limit the width of your antennas elevation lobe, since ga...
by snn47
Thu Dec 05, 2019 4:49 am
Forum: RTL-SDR Discussion
Topic: Newbie : listening 3Khz to 148 Khz with upconverter ?
Replies: 8
Views: 999

listening 3Khz to 148 Khz with upconverter ?

Yes, If the upconverter is not limited by a High-Pass and really passes all signals received to the mixer and provides an upconversion. You can verify receptions using one of themany strong time reference signals closest to you, e.g. DCF-77 on 77.5 kHz in Mainflingen Germany, which are used e.g. by ...
by snn47
Wed Dec 04, 2019 7:21 am
Forum: Other SDR Devices
Topic: SDRplay announces the RSPdx
Replies: 8
Views: 1377

Re: SDRplay announces the RSPdx

@radiolistener For example, here is comparison between SDRPlay and RTLSDR on short wave, both connected to the same antenna and working simultaneously. Do you see any advantage of SDRPlay against RTLSDR? I don't. ;) It is diffuicult comparing pictures, but looking at the sidebands and the two signal...
by snn47
Wed Dec 04, 2019 6:57 am
Forum: Other SDR Devices
Topic: SDRplay announces the RSPdx
Replies: 8
Views: 1377

Re: SDRplay announces the RSPdx

In this discussion receiver performance and the point where an antenna and/or cable are connected to the receiver need to be seen seperately. PS: These comments are no tintended to discourage anyone, but I am trying to point out that at such low frequencies, you can only try to find the best comprom...
by snn47
Sat Nov 30, 2019 10:53 am
Forum: RTL-SDR Discussion
Topic: maximum transmision range.
Replies: 3
Views: 509

Re: maximum transmision range.

1 NM = 1.852 km

179 NM ~330 km
by snn47
Fri Nov 29, 2019 11:32 pm
Forum: RTL-SDR Discussion
Topic: maximum transmision range.
Replies: 3
Views: 509

Re: maximum transmision range.

The theoretical Radio Line of sight (RLOS) is ~ 1.23 * (SQRT 2000ft +SQRT 10000ft) ~178 NM. No one will be able to give you a reliable estimate for the actual achieveable range since there are many factors to consider, e.g. antenna gain and variation of real lobed antenna pattern, the difference bet...
by snn47
Sat Nov 23, 2019 10:52 am
Forum: RTL-SDR Discussion
Topic: Direction Finding brainstorm- log spectrum via Doppler antenna system?
Replies: 1
Views: 274

Re: Direction Finding brainstorm- log spectrum via Doppler antenna system?

Is your Doppler antenna b asis really large enough to get an audible tone?