SWLing Post Message Board

in practice it's invisible and. being a loop. it also helps taming the QRM https://www.kk5jy.net/porch-loop/ if one doesn' t feel comfortable in winding the voltage BalUn, the NooElec 9:1 v2 will fit, just ensure to use low loss coax (e.g. RG6, avoid the RG58 !) and add 10 or more snap on ferrite ri...

then one may add some filters https://gpio.com/collections/notch-filters between the antenna and the LNA in EU or at Least in Italy one may want this https://gpio.com/collections/notch-filters/products/fm-notch-filter-88-108mhz-excellent-rejection-85db to keep commercial FM from.saturating the LNA a...

13dka wrote: ↑Sun Apr 27, 2025 8:46 am Can't wait to make and try one of those! (Will take a while tho.)

tried it, works as described, less gain than the SULA but much easier to carry around and for permanent setups more resistant to winds

an example

https://gpio.com/collections/low-noise- ... -30db-gain

the LNA above should fit pretty well the SULA loop

Preamplifiers (LNAs), low/high/bandpass/notch filters, Bias-T units and other RF "building blocks"

https://gpio.com/

HTH

https://practicalantennas.com/designs/v ... s/5eights/

and the above deals with vertical antennas

Also applies to other horizontally polarized antennas

https://www.voacap.com/2023/antennas/sq ... of-dipole/

For the interested ones, here's another idea to build the compact loop, the attached image shows all the relevant details, the resistor may be a regular one (although a non inductive one would be better), the 9:1 can be the commercial NooElec BalUn or can be built using a #73 binocular core, the PVC...

I was wondering if it would be worthwhile to minimize losses within the antenna elements and if that's even possible? For example, I was using PE or PVC insulated stranded wire with a velocity factor of maybe 0.7 or something. Somewhere I picked up the idea that this slowdown in the dielectric come...

Maybe it's a crazy idea, but... let's start from this https://www.rtl-sdr.com/kiwisdr-tdoa-direction-finding-now-freely-available-for-public-use/ now, let's suppose to put together some code which, by leveraging the above and some map API, may feed an AI to gather further infos (e.g. using search en...