Log antenna comparison Loop on the ground
Вставка
- Опубліковано 14 жов 2024
- Here is a comparison of a high dipole versus a (Loop on the ground) LOG antenna. For my QTH with my dipole located close to the noisy solar power system, the improvement is dramatic.
Impressive demonstration of the LOG, Paul. Keep up the great work on these videos. 73 Ken -- WBØOCV
Thank you Ken appreciate you watching and commenting. Sorry again about the audio W1VLF
Nice results there! What a difference. SNR usually improves even more when you stack them. I wasn’t so lucky though. Nothing but the regular noise when I connected to the logs stacked against the shed. Fine pine…. Might try oak next time.
Thank you! I'm considering making that type of an antenna to work with my RSPDx. I'd really love to see comparison between good broadband amplified loop (like Wellbrook, CrossCountry Wireless or Lz1aq) placed closed to the house and compared to LoG (close to house or away from the house). Small magnetic loops should have low sensitivity to the near field noise (within 1/8 or 1/4 of the wavelength between noise source and the loop).
Excellent video Paul, tnx for sharing. I made one but twice the dimensions to go lower in frequency and was pleasantly surprised. Remember, one cannot have enough/different receive antennas when trying to pick up different signals. 73
Hi Gedas I may try putting another large unit out farther into the woods myself. W1VLF
@@W1VLF What is also neat is our current ability to half-way accurately model these types of antennas, even when on the ground. I got some neat results as far as radiation patterns and feedpoint impedances. GL es good DX ! 73
Highly impressed. For HF reception, a LOG seems the go-to antenna at yours.
Of course, in the woods, be careful which logs you connect to.
Hi Paul.... LOL Maybe I should connect a coax to tree and see what happens!! Yes this antenna seems to work quite well especially since it is so far away from the noise sources... W1VLF
Wow, this is amazing, thanks! I've been wanting to set up a LOG for a while now, but I think this clinches it. The difference in S/N ratio is phenomenal. Cheers!
Thank you for watching !! W1VLF
Your results were the exact opposite of mine. The LOG was deaf, where S9+20 signals decreased to S4.
Hi Bob... without the preamp, the signals are very weak as you say. But with the preamp things are much different. The preamp has about 20 db of gain. The preamp is needed since the antena is on the ground!! W1VLF
Thanks!
Hello Sam, Thank you so much for your kind donation to the channel It is really appreciated!! W1VLF
Have you tried to determine if the noise on the dipole is common mode noise on the feedline traveling up to the dipole? Too many times this is what I've found to be the reason, and in some cases I had to apply common mode filtering at both ends of the feedline. For my current active loop (pun not intended) I had to install common mode filtering on both the feedline and the rotor cable, at both ends.
Hello.. That's is indeed a very good question.. Yes I have used common mode chokes extensively on this an other bands. This is actually radiated noise on the DC side of the line tie inverter. The common mode chokes have had no impact on this problem. Excellent question. BTW I have a number of videos on the topic of CMC W1VLF
BTW, what preamp do you have between LoG and RSPDuo?
Hi Sam.. Hope that correct. I am using an ARR Advanced receiver research preamp. There is nothing special about,. It has 20 dB gain and a relatively low noise figure throughout HF. 50 Ohm input and output impedance of course. The other things you might see in the video is a patch panel that allows me to use different SDDR and antenna combinations
Glad I don't have solar.
Hi Richard... This is a Solar Edge System which is very noisy. Typically the Enphase systems are much much quieter!!