Search found 64 matches

by snn47
Mon Nov 27, 2017 8:57 pm
Forum: Troubleshooting Help
Topic: USB Isolator + RTL-SDR V3 "no device selected"
Replies: 6
Views: 257

Purpose of USB Isolator

PS.: What do you hope to gain by using a USB isolator? From my understanding USB isolator are intended to provide galvanic isolation for the USB Ports only, e.g. for medical purposes, but are also used by audiophiles. Optical Isolator are in my understanding not intended to necessarily eliminate noi...
by snn47
Mon Nov 27, 2017 8:31 pm
Forum: Troubleshooting Help
Topic: USB Isolator + RTL-SDR V3 "no device selected"
Replies: 6
Views: 257

Some USB 2.0 Isolator

I just did a quick check and found a cheaper one that is USB 2.0 only https://www.reichelt.de/?ARTICLE=179183&PROVID=2788&gclid=EAIaIQobChMI36aDtMjf1wIVi0AbCh1FtgY2EAQYAyABEgKdOPD_BwE for 249 €. Some are based on Analog Devices ADuM3160. The chip is only 7,30 €? https://www.reichelt.de/?ARTICLE=1135...
by snn47
Tue Nov 07, 2017 9:29 pm
Forum: RTL-SDR Discussion
Topic: Oscillator Frequency
Replies: 2
Views: 174

Re: Oscillator Frequency

by snn47
Sat Nov 04, 2017 8:50 pm
Forum: Off-Topic
Topic: Pinnacle Miro PCTV
Replies: 5
Views: 688

Re: Pinnacle Miro PCTV

To get an answer you have to provide more information. Which services/signals do you mean by "hear planes"? SW, VHF/UHF, L-Band or higher? Which product designation has your card? Is it for terrestrial or satellite TV use? While the other reply is correct, that RTL-SDR based software is not supporte...
by snn47
Sat Nov 04, 2017 8:30 pm
Forum: Signal Identification Help
Topic: 171MHz signal
Replies: 1
Views: 151

Re: 171MHz signal

Except for airborne and satellite operated transmitter, VHF is limite to Radio Line of sight. Since only you know which ITU-region, country and location you are located it, it will be hard to deduct the source. Are you shure it is a real signal and not some intermodulation product of other strong si...
by snn47
Sat Nov 04, 2017 8:20 pm
Forum: Antennas
Topic: Antenna for SW CHU time. 3.33, 7.850 & 14.67 Mhz
Replies: 7
Views: 1547

Re: Antenna for SW CHU time. 3.33, 7.850 & 14.67 Mhz

If you live in Europe there is e.g. DCF 77(.5 kHz), which is used by self synchonizing clocks. I assume that other regions have similar low frequency references and equipment that uses them, that you can use as basis for your trials.
by snn47
Sat Nov 04, 2017 8:16 pm
Forum: Antennas
Topic: Antenna for SW CHU time. 3.33, 7.850 & 14.67 Mhz
Replies: 7
Views: 1547

Re: Antenna for SW CHU time. 3.33, 7.850 & 14.67 Mhz

Rather than adding filter, for your purposes the antenna should tuneable to provide the selectivity instead in order to relieve the Rx from strong unwanted signals. While coils on ferrites, like the ones found in AM-Rx, would be smaller they most likely won't work above 2 MHz. That leaves Magnetic (...
by snn47
Wed Oct 25, 2017 5:28 am
Forum: User Projects
Topic: Pluto xmit used as LO for mixer ??
Replies: 6
Views: 614

Alternative to Re: Pluto xmit used as LO for mixer ??

Maybee an alternative "35-4400 MHz with a new ADF4351 board"

https://translate.google.de/translate?h ... 51_neu.htm

Like for the Pluto SDR I could not find information on suppression of spurious emissions
by snn47
Sat Oct 21, 2017 3:38 pm
Forum: Antennas
Topic: Is there a good general purpose ANTENNA
Replies: 5
Views: 4268

Re: Is there a good general purpose ANTENNA => NO!

NO! You can't beat physics since the receiver are much to wideband for a single passive antenna, if you want to receive also below 30 MHz than it's even more complicated. Most antennas are very frequency selective (at best a few percent of the frequency) Passive antennas are broader, but at best 1 t...
by snn47
Sat Oct 21, 2017 2:58 pm
Forum: RTL-SDR Discussion
Topic: How does the image rejection filter in the R820T(2) work?
Replies: 3
Views: 944

Re: How does the image rejection filter in the R820T(2) work

Suppose, for example, that I tune an RTL-SDR to 903.57MHz. The IF is 3.57MHz so the LO is tuned to 900MHz (assuming a low-side injection) If you assume a assuming a high-side injection (1.8 GHz to 3 GHz) the BP would not be required. https://www.rtl-sdr.com/using-the-rtl-sdr-as-a-transmitter/ Here ...