Hi guys, I am about to add a common mode choke to isolate the antenna from its feedline to each of my beverages and I only have FT240-61 ferrites. My question is how many turns should I do on the fer
Hi Filipe Zero , you should use material #31 or #77 , The core you have is not good for low bands. JC N4IS --Original Message-- From: Topband [mailto:topband-bounces@contesting.com] On Behalf Of Fili
Hello JC, Thanks for your answer. I just ordered a few 2631803802 and 5943003801 from mouser. With these ferrites I ask the same question, should I put the choke close to the 9:1 Balun or near the sw
If you must use FT240-61, then in a single layer about 18 turns of RG58 would fit, which should give you ~600 Ohms on 1.8 MHz. That would be very good for a dipole, but for a Beverage a much higher i
With 5943003801 and RG58, closely fill-in a single layer, leaving 10-15 mm on the outside perimeter unused. That should be ~16 turns, giving you impedance near 4000 Ohm. Such a choke should be placed
Use the #31 material. Wind at least 20 turns of RG58 around it. Place it as close to the 9:1 transformer. 73, Jim K9YC _________________ Topband Reflector Archives - http://www.contesting.com/_topban
Thanks Jim and all for the help. Mix #31 cores are already ordered in mouser. 73's cu on low bands Filipe LOPES CT1ILT CR6K _________________ Topband Reflector Archives - http://www.contesting.com/_t
Author: Eduardo Araujo via Topband <topband@contesting.com>
Date: Mon, 12 Oct 2015 18:14:42 +0000 (UTC)
My two cents......It was interesting during the installation of the last beverage, we have only #31 core, so we placed it at the receiver side. Disconnecting the coax at the bev feed point and short
This is exactly as expected. In the first case you fed all the RF received by the outer surface of the coax directly inside the coax, and directly to your RX input. In the second case, a significant
Hi Felipe It works like a voltage divider where the impedance to ground should be lower as possible to give you more attenuation like 1k/500ohms versus 1K/5 ohms divider. You should use the choke nea
Yes. But to expand on this -- often the interference is coupled into a gain stage or RX by a Pin One Problem. ALWAYS make the first connection of any cable shield to the shielding enclosure of EVERY
Thanks for this grounding tip too Jim. 73's Filipe Lopes CT1ILT - CR6K F4VPX - TM3M _________________ Topband Reflector Archives - http://www.contesting.com/_topband
Thanks for this testing suggestiong Eddie, it will sure be a good way to check if it works or not. 73's Filipe Lopes CT1ILT - CR6K F4VPX - TM3M _________________ Topband Reflector Archives - http://w
Thanks JC, I am reading it right now, very interesting indeed. 73's Filipe Lopes CT1ILT - CR6K F4VPX - TM3M _________________ Topband Reflector Archives - http://www.contesting.com/_topband