Jul 19, 2014 · MFJ-915 RF Isolators are 1:1 ferrite chokes designed to be placed in line with 50-Ohm coax. These RF Isolators are effective from 1.8 to 30 MHz at full SSB legal power. They were designed to improve the performance of all amateur stations, fixed or mobile. MFJ RF isolators reduce or eliminate stray RF often found on coax shields.

Jul 23, 2015 · Almost every one wrote how great these mfj 915 's worked. I know the air would choke should be 2' below the feed point. I know this is made out of ferrits and the wound choke is just thst, wound coax there usually placed àt 2' brlow the feed point so I'm thinking 2' eould br good but trust be told I've absolutely no idea of where exactly this ...

Mar 8, 2010 · The MFJ-915 is made up of 50 ferrite core beads placed on a 13-inch length of RG-303 coaxial cable. The coax and SO-239 connectors have Teflon insulation for maximum insulation and life of the product. The RF Isolator is enclosed in a Schedule 40 PVC pipe for strength and protection.

Apr 8, 2005 · That MFJ-915 is the same thing as a coax choke, it just uses ferrite 'beads' instead of a coil of coax. It isn't a balun, by the way, and why MFJ calls it a "Line isolator". It can be placed at the radio or at the antenna end of the feed line, it won't make a huge difference.

Aug 14, 2014 · My LMR 400 and pl 259 double connector (for the mfj 915) hasn't arrived yet. I'm looking forward to not only the install but I'm kinda nervously anticipating the moments right after the antenna's up, all the cables are hooked up then the moment when I key the mic and watch my no calibrate swr meter emedietly jump to the swr reading..

Jun 11, 2006 · Recieved my MFJ - 915 RF ISOLATOR today..the instructs say ''the rf isolater should be placed close to the transmitter'' and also it says '' install the rf isolater by connecting the coax cable from your antenna to one end of the isolater . '' …

Aug 8, 2015 · The Imax 2000 will be going up at 12' with the mfj 915 connected to it's so 239 via a double male 259. If it works it works. If not ill move on and possibly go with my coax made 11 meter dipole in a horizontal configuration (purchased off an eday seller who makes them for every band from 10-160 and they look well made).

Aug 8, 2015 · Does it matter which end of the MFj 915 gets installed onto my pl 259's antenna feed? I'm assuming it doesn't matter but without any help from the instructions I just dont know. I just want to confirm if it's lettering should be right side up or …

Jan 21, 2021 · The MFJ-915 RF Isolator is a 1:1 Current Balun designed to be placed in line with a 50-Ohm coax. The RF Isolator is effective from 1.8 to 30 MHz. It was designed to improve the performance of all amateur stations, fixed or mobile. MFJ-915 will reduce or eliminate stray RF often found on coax.

Aug 11, 2015 · Can the antenna be tuned at feedpoint without use of 9ft of coax? Answer is yes. So mast becomes counter poise.