Search found 127 matches
- Wed Aug 31, 2022 1:51 pm
- Forum: General Discussion
- Topic: The SULA antenna
- Replies: 63
- Views: 91650
Re: The SULA antenna
While more serious experiments and comparisons with other antennas are still due, I felt like just practically experiencing the SULA the last few times out at the dike, particularly when the condx were briefly recovering between flares. Just like Thursday last week, when the solar indices looked bet...
- Tue Aug 02, 2022 12:50 am
- Forum: General Discussion
- Topic: The small SWL beam (1...30 MHz)
- Replies: 117
- Views: 59718
Re: The small SWL beam (1...30 MHz)
check this one http://www.kk5jy.net/lla/ :D as for the fence, assuming it's iron or the like, given the length you should consider that it will already have quite some resistance; it would be interesting to try turning it into a beverage antenna, that would require a resistor termination and quite ...
- Mon Aug 01, 2022 12:26 pm
- Forum: General Discussion
- Topic: The small SWL beam (1...30 MHz)
- Replies: 117
- Views: 59718
Re: The small SWL beam (1...30 MHz)
as for NEC inductance, I don't have NEC at the moment, but if you want, here's how to add it [...] it's a matter of adding an LD tag line similar to the one used for the resistor, a starting value of 1uH (1.00e-06) could be ok for testing, then the NEC optimizer will help optimizing the value to ac...
- Sat Jul 30, 2022 1:20 pm
- Forum: General Discussion
- Topic: The small SWL beam (1...30 MHz)
- Replies: 117
- Views: 59718
Re: The small SWL beam (1...30 MHz)
The point is that going down in frequency the SDL gain drops with a quite steep curve, now the first workaround which came to my mind was a higher gain preamp, but I'm not convinced it may solve the problem The practical behavior reflects the simulation to the i-dot in this regards and I'm entirely...
- Sat Jul 30, 2022 8:22 am
- Forum: General Discussion
- Topic: The small SWL beam (1...30 MHz)
- Replies: 117
- Views: 59718
Re: The small SWL beam (1...30 MHz)
That's shortwave for ya: Conditions started out disturbed but OK-ish yesterday night until local midnight (UTC+2) and then went downhill so much that even the FT8 signals almost disappeared on 17m (rarely seen that happening) and the entire US slowly faded out on 20 towards sunrise, instead of the W...
- Fri Jul 29, 2022 10:14 pm
- Forum: General Discussion
- Topic: The small SWL beam (1...30 MHz)
- Replies: 117
- Views: 59718
Re: The small SWL beam (1...30 MHz)
At the dike, finally getting to compare antennas I just had the 2nd LANA HF dying on me on the SDL grrr. Now running only the one I bought that has less gain and the comparison with the amplified Youloop is over. It was a bit pointless anyway because the YL (as a stand-in for an active SML) compared...
- Thu Jul 28, 2022 10:52 am
- Forum: General Discussion
- Topic: The small SWL beam (1...30 MHz)
- Replies: 117
- Views: 59718
Re: The small SWL beam (1...30 MHz)
Well, I had to clearly state that the SDL is "open" then nothing forbids one from turning the design into a commercial product an selling it, all in all, someone did that with the LoG :lol: and then maybe someone in China will decide to copy the design, screw it badly and sell some kind o...
- Wed Jul 27, 2022 9:56 pm
- Forum: General Discussion
- Topic: The small SWL beam (1...30 MHz)
- Replies: 117
- Views: 59718
Re: The small SWL beam (1...30 MHz)
it's easy to see that w/o the resistor in place, the resistive part of impedance becomes very low while the reactive one raises, this in turn causes losses and may probably cause problems if using the SDL with an external preamp or with a receiver which doesn't "like" too much impedance m...
- Wed Jul 27, 2022 2:51 pm
- Forum: General Discussion
- Topic: The small SWL beam (1...30 MHz)
- Replies: 117
- Views: 59718
Re: The small SWL beam (1...30 MHz)
Hmm... I see, now here's an idea (no masterpiece of art :D !) SDL_setup.png not sure it will solve the fiberglass pole issues, but at least may allow to better distribute the load thanks to the additional supporting rope; I wonder if, by using some PVC pipes inserted over the larger section of the ...
- Wed Jul 27, 2022 7:00 am
- Forum: General Discussion
- Topic: The small SWL beam (1...30 MHz)
- Replies: 117
- Views: 59718
Re: The small SWL beam (1...30 MHz)
As for support, maybe it's a crazy and too complex idea, but just to play some "brain storming", check the pic below Thanks for the effort, Andrew! But the problem isn't so much the dangling coax (which is ~1m, neither much to dangle nor much weight), it's the weight distribution on a rat...