Search found 243 matches

by snn47
Sun Feb 14, 2021 12:06 pm
Forum: Antennas
Topic: Best antenna for HF
Replies: 8
Views: 1525

Re: Best antenna for HF

Unless you use direct sampling, yes.
by snn47
Sun Feb 14, 2021 5:45 am
Forum: Antennas
Topic: Best antenna for HF
Replies: 8
Views: 1525

Re: Best antenna for HF

In short: There is no antenna that provides you good reception, especially at HF with this dimensions, because you can't beat physics! You can receive with everything, starting from a wet noodel cooked in salt water, a 1 ft nail for VHF and a few meter of wire for HF. If it conducts it will receive....
by snn47
Sat Feb 13, 2021 10:43 am
Forum: Antennas
Topic: Log-periodic antenna for UHF
Replies: 4
Views: 913

Re: Log-periodic antenna for UHF

Depends on the type of feed line. If you have a symetrical feed line like a chicken wire (two parallel wires spearated by some form of plastic), you don't a Balaun at the antenna but at the end when you convert to a coax system, this is why early TV had the Balaun inside the TV-receiver at the symet...
by snn47
Sat Feb 13, 2021 10:34 am
Forum: Antennas
Topic: Can anyone recccomend an antenna ?
Replies: 1
Views: 258

Re: Can anyone recccomend an antenna ?

No one can answer your question if you do not provide the bare minimum of information e.g. specify your "small antenna" in relation to the frequency range you want to receive, is it (omni-) directional, where did you place it indoor, which floor, are the walls steel reinforced or outdoor, on ground ...
by snn47
Fri Dec 25, 2020 8:38 pm
Forum: RTL-SDR Discussion
Topic: RTL-SDR up to 6 GHz via a Harmonic Mixing- can frontend modifications improve sensitivity?
Replies: 0
Views: 536

RTL-SDR up to 6 GHz via a Harmonic Mixing- can frontend modifications improve sensitivity?

Tuning an R820T2 RTL-SDR up to 6 GHz via a Harmonic Mixing Driver Hack provides information about an softwarehack that allows to to use the 5th harmonic on R820T2 RTL-SDRs to receive frequencies above the normal 1.766 GHz limit https://www.rtl-sdr.com/tuning-an-r820t2-rtl-sdr-up-to-6-ghz-via-a-harmo...
by snn47
Tue Dec 22, 2020 6:44 pm
Forum: Antennas
Topic: Self-building my first dipole antenna
Replies: 1
Views: 484

Re: Self-building my first dipole antenna

Have you looked at "antenna related information and guidance for asking questions to improve chances for an answer"? In addition coaxcable- Balauns and Ferrite-Baluns there are other versions to achive balanced to unbalanced feedin, just check amateur radio websites for building a 10 m dipole and in...
by snn47
Tue Dec 15, 2020 8:48 pm
Forum: Antennas
Topic: NanoVNA versions and clones - what are the differences and drawbacks
Replies: 2
Views: 655

NanoVNA versions and clones - usefull addons

If you look through the links provided at the page from DG8SAQ "VNWA3" I found a Automatic SMA Calibrator for DG8SAQ VNWA 3 Series onn the https://www.sdr-kits.net page I found an Automatic SMA Calibrator for DG8SAQ VNWA 3 Series https://www.sdr-kits.net/Magi-Cal-Automated_SMA_Calibrator_for_VNWA. A...
by snn47
Tue Dec 15, 2020 8:12 pm
Forum: Antennas
Topic: NanoVNA versions and clones - what are the differences and drawbacks
Replies: 2
Views: 655

NanoVNA versions and clones - links to documentation and guidance

Here is a collection of links or webpages providing links The concept used for the NanoVNO DG8SAQ VNWA2.x / VNWA3 Information with lots of links and relevant information http://www.dg8saq.darc.de/VNWA21/index.html NanoVNA versions NanoVNA https://nanorfe.com/nanovna-versions.html#versions BH5HNU's 3...
by snn47
Tue Dec 15, 2020 8:02 pm
Forum: Antennas
Topic: NanoVNA versions and clones - what are the differences and drawbacks
Replies: 2
Views: 655

NanoVNA versions and clones - what are the differences and drawbacks

I want to order NanoVNA and would like to know what are the hardware differences between the original designs and clones. Does anyone know of a site that compared the differences between the original and the clone designs similar to the different RTL-SDR designs and clones? From what I read all desi...
by snn47
Tue Dec 15, 2020 6:33 pm
Forum: Off-Topic
Topic: Is it my old age?
Replies: 9
Views: 2259

Re: Is it my old age?

Maybee you could change the topic to something like "137 MHz NOAA preamp" to make this thread easier to find I just checked, there are a number of 137 MHz preamps with bandpath filter available, e.g. https://www.wraase.de/de/shop/#aa-137 http://www.hf-berg.de/HFC/vorverstaerker_weissblech.htm look f...