Search found 253 matches

by snn47
Tue Jun 08, 2021 7:40 pm
Forum: RTL-SDR Discussion
Topic: up-/down-converter, what is the best IF frequency to use?
Replies: 2
Views: 298

Re: up-/down-converter, what is the best IF frequency to use?

Thank you, I am obstructed by slopes in all directions and since all analogue terrestrial TV is replaced by DVB-T2 I should be able to find some free spectrum :).
by snn47
Sat May 29, 2021 9:24 pm
Forum: RTL-SDR Discussion
Topic: up-/down-converter, what is the best IF frequency to use?
Replies: 2
Views: 298

up-/down-converter, what is the best IF frequency to use?

I am looking for some information on the frequencies that the orange curve in simplified picture for the RTL-SDR is valid for? _#RTL-SDR spurs.png For shortwave reception I already have several up-converter, which provide the up-converted output at an IF (Intermediate Frequency) between 144 to 146 M...
by snn47
Fri May 28, 2021 7:49 pm
Forum: RTL-SDR Discussion
Topic: Tracking/Triangulating pulsed RF Signals
Replies: 8
Views: 797

Re: Tracking/Triangulating pulsed RF Signals

From the occurances you mentioned only the first fall into the the possibly electronic caused category Is the Door Entry Phone a wireless device or connected via cable, battery powerd or AC.powered. The other ones are obviously cable connected to the AC power lines. - Printer restarts with no obviou...
by snn47
Fri May 28, 2021 6:36 pm
Forum: Antennas
Topic: Which is the best BALUN design and core material for DIY Möbius antenna design?
Replies: 0
Views: 98

Which is the best BALUN design and core material for DIY Möbius antenna design?

corrections made on 2021.5.29 Since the Airspy Loop was sold, there have been multiple discussions on the Möbius and shielded type loop antennas, which both are fore receive only. Can anyone provide details on the ferrite BALUN used in the Airspy Loop, e.g. the number of windings, how many windings...
by snn47
Thu May 27, 2021 9:49 pm
Forum: RTL-SDR Discussion
Topic: Tracking/Triangulating pulsed RF Signals
Replies: 8
Views: 797

Re: Tracking/Triangulating pulsed RF Signals

The most obvious question to me, have you contact BAKOM (that should be the Swiss PTT authorithy in my knowledge) and asked them to identify the RFI source and to close it down? From the legal point for any PTT authority to act is to ask the question is it really an interference or is the design of ...
by snn47
Thu May 27, 2021 8:56 pm
Forum: Other SDR Devices
Topic: Spectrum Analysis for Beginners
Replies: 2
Views: 477

Re: Spectrum Analysis for Beginners

Why would you want to looke into 5 GHz WLAN, when Bluetooth is in the ISM bands, from 2.402 GHz to 2.48 GHz. Since you wrote intermittent, it could be also other devices besides Bluetooth or WLAN, e.g. microwave oven that also work in this ISM-band at ~2.4 GHz. If you read a few post down https://ww...
by snn47
Sun May 09, 2021 8:03 pm
Forum: Antennas
Topic: Connecting RTL-SDR V3 on master antenna system in the building
Replies: 5
Views: 821

Re: Connecting RTL-SDR V3 on master antenna system in the building

Even though you will not meassure a voltage when you meassure it with a DVM, you should consider also damage by an Electrostatic Static Discharge, (ESD), when you connect your receiver to the house antenna ports. Only if the receiver is powered by a notebook which is solely operated by it's batterie...
by snn47
Sat Mar 27, 2021 9:09 pm
Forum: Antennas
Topic: UHF (SO-239) antenna bases?
Replies: 6
Views: 1363

Re: UHF (SO-239) antenna bases?

Any mismatch between the receiver, the transmission line and associated components (e.g. connect-or, switches) and the antenna will have some impact on how much the signal from the antenna is attenuated, before it is at the receiver antenna input., but it does not determine if a antenna is providing...
by snn47
Fri Mar 26, 2021 9:49 pm
Forum: Antennas
Topic: Question regarding loop designs
Replies: 10
Views: 7291

Re: Question regarding loop designs

You asked for advice, but choose to not answer questions and ignore facts. As Bruce asked what is the frequency range you want to use it and what frequencies did you do your test on? What loop design did you use, e.g. <1/4 wavelength and tuned, a Moebius based antenn design, or just a coil type ante...
by snn47
Fri Mar 26, 2021 9:23 pm
Forum: Antennas
Topic: UHF (SO-239) antenna bases?
Replies: 6
Views: 1363

Re: UHF (SO-239) antenna bases?

There are a lot of incorrect statements in this reply, the most important is A dipole antenna has 3db gain in free space over a narrow frequency range. Outside of this frequency range the impedance mismatch makes the antenna inefficient. Antenna efficiency meaning how much power of a signal is recei...