Reduce RFI with a Common Mode Choke | Page 5 | QRZ Forums
Sep 29, 2021 · I tried snap-on beads and an air choke wound around a coke bottle (both helped but did not fix the problem), and this morning I added a common-mode choke. This one is 12 turns of RG-8x wound around a circular ferrite core (mix 31) and received some interesting results.
Reduce RFI with a Common Mode Choke - QRZ Forums
Sep 29, 2021 · Common Mode Current on your coax can really mess up causing RFI and interference in the shack. In addition, you could also be receiving unwanted interference on the coax outer shield. In this video I show how I built myself an easy CMC choke using a …
Reduce RFI with a Common Mode Choke | Page 6 | QRZ Forums
Sep 29, 2021 · Huge, the one in the video is comprised of two ~100 Ohms transmission lines in parallel to produce 50 Ohms while at the same time reduces the total of common-mode rejection in half. The same number with coax will be twice better as well as will heath the ferrite less compared to chokes wound with two wires.
Reduce RFI with a Common Mode Choke | Page 7 | QRZ Forums
Sep 29, 2021 · I have made Peter’s 1:1 common mode choke and his 4:1 and 9:1 baluns testing as he does in the videos. They certainly test out ok. I have also wound coax common mode chokes which have tested out. Frankly I have not noticed any difference between the two common mode chokes. As to the coax wound chokes, I have to say that I have seen two designs.
Reduce RFI with a Common Mode Choke | Page 8 | QRZ Forums
Nov 9, 2021 · Common Mode Current on your coax can really mess up causing RFI and interference in the shack. In addition, you could also be receiving unwanted interference on the coax outer shield. In this video I show how I built myself an easy CMC choke using a …
Reduce RFI with a Common Mode Choke | Page 3 | QRZ Forums
Sep 29, 2021 · But (a) RG58 is pretty poor coax, even at HF. RG8-X and similar are much better quality, for much the same ballpark price. (b) I would never wind a toroid with coax. The additional 'connector losses' mentioned are absolutely miniscule at HF. If you want to eliminate common mode without cutting/interrupting the coax, just use a series of split ...
Reduce RFI with a Common Mode Choke | Page 2 | QRZ Forums
Sep 29, 2021 · The choke can be wound onto the existing cable -- no connectors needed. ...otherwise should yield the same results in choking. One advantage of the wire vs coax is that the coax has a limit on radius bend / diameter and the center conductor can migrate and short out to the shield, especially with foam coax, when wound too tightly.
Are antennas altered in the presence of carbon fiber masts?
Mar 15, 2021 · The N9TAX antenna used in the test has a reasonably effective choke at the feed point that I've verified suppresses common mode tendencies by about 10 dB. I guess I could add another one 1/4 wave down for the coup de grâce, but that will have to wait for another time.
Loop On Ground Antenna | QRZ Forums
Jul 18, 2021 · Possible improvement may come from a common mode choke, or a balun at feedpoint. WL7PM, Jul 20, 2021 #8 ...
Wolf River Coil Antenna Tips, Tricks and Modifications
Sep 23, 2020 · I have been using the Wolf River Coil antenna system for a few years now and wanted to share my tips, tricks and modifications.