Search found 299 matches

by Andrew (grayhat)
Sat Nov 15, 2025 7:02 pm
Forum: Questions & Advice
Topic: Generate your personal azimuthal map
Replies: 10
Views: 326679

Re: Generate your personal azimuthal map

Another idea, first generate the map, then use this

https://rasterbator.net/

to turn it into a wall size poster :)

useful if your shack has an empty wall :D
by Andrew (grayhat)
Sat Nov 15, 2025 7:01 pm
Forum: Questions & Advice
Topic: Generate your personal azimuthal map
Replies: 10
Views: 326679

Re: Generate your personal azimuthal map

Another idea, first generate the map, then use this

https://rasterbator.net/

to turn it into a wall size poster :)
by Andrew (grayhat)
Tue Oct 28, 2025 3:15 pm
Forum: General Discussion
Topic: The T2FD antenna
Replies: 2
Views: 200710

Re: The T2FD antenna

totally agreed !!
by Andrew (grayhat)
Tue Oct 28, 2025 2:49 pm
Forum: Questions & Advice
Topic: Saveitforparts: Listening in on Russian Soldiers Hijacking US Military Satellites
Replies: 5
Views: 298903

Re: Saveitforparts: Listening in on Russian Soldiers Hijacking US Military Satellites

this simple antenna https://www.youtube.com/watch?v=Nyttl277ehs can easily be recalculated for the satellites and will offer about 9dB gain at 11° so it may fit start by calculating the wavelenght (Lambda) then multiply it by (about) 1.138 done so you'll have the loop perimeter, the short side will ...
by Andrew (grayhat)
Mon Oct 27, 2025 2:59 pm
Forum: General Discussion
Topic: The T2FD antenna
Replies: 2
Views: 200710

The T2FD antenna

the T2FD "all band" antenna was a military secret till around 1950 when informations about this aperiodic "all band" antenna started to spread https://en.wikipedia.org/wiki/T2FD_antenna yet, the data about calculation behind this antenna arem't clear, so after some ferreting on t...
by Andrew (grayhat)
Mon Oct 27, 2025 2:32 pm
Forum: Questions & Advice
Topic: Saveitforparts: Listening in on Russian Soldiers Hijacking US Military Satellites
Replies: 5
Views: 298903

Re: Saveitforparts: Listening in on Russian Soldiers Hijacking US Military Satellites

old military satellites are currently being actively used by some unintended entities I've received FLTSAT transponders with all external antennas I've ever used, including regular 60ft wire dipoles, big loops, small active loops or a huge vertical. With a small log-periodic for UHF/VHF pointed SW ...
by Andrew (grayhat)
Thu Oct 23, 2025 4:50 pm
Forum: Questions & Advice
Topic: Saveitforparts: Listening in on Russian Soldiers Hijacking US Military Satellites
Replies: 5
Views: 298903

Re: Saveitforparts: Listening in on Russian Soldiers Hijacking US Military Satellites

As a note, I've been playing with SDRAngel lately https://www.sdrangel.org/ and amongst other features https://github.com/f4exb/sdrangel/wiki/Quick-start the program offers a nice satellite tracker which eases aiming the antenna at a given "bird" :) oh and also see https://github.com/f4exb...
by Andrew (grayhat)
Tue Oct 21, 2025 3:33 pm
Forum: Questions & Advice
Topic: Saveitforparts: Listening in on Russian Soldiers Hijacking US Military Satellites
Replies: 5
Views: 298903

Saveitforparts: Listening in on Russian Soldiers Hijacking US Military Satellites

Sounds like somed old military satellites are currently being actively used by some unintended entities, including some truckers and fishermen from Brazil and Russian soldiers in Ukraine, I found the infos here https://www.rtl-sdr.com/saveitforparts-listening-in-on-russian-soldiers-hijacking-us-mili...
by Andrew (grayhat)
Thu Sep 25, 2025 10:31 am
Forum: General Discussion
Topic: Antenna gain explained
Replies: 0
Views: 101230

Antenna gain explained

a rather interesting piece written by Tom Rauch W8JI

https://w8ji.com/quad_cubical_quad.htm

which clears prettty well the concept of gain, plus some links regarding noise and more stuff worth some attention imVHo

HTH
by Andrew (grayhat)
Sun Jul 13, 2025 8:54 pm
Forum: Questions & Advice
Topic: WSPRSONDE
Replies: 1
Views: 574812

WSPRSONDE

Wanna help with WSPR and propagation research ? If so, please, have a look here https://turnislandsystems.com/host-a-hamsci-wsprsonde-also-turn-island-systems-in-qst/ "The HamSCI package will include the WSPRSONDE, a 9-Band Filter-Combiner, a Bodnar GPSDO, an 80-10 meter end-fed halfwave antenn...