Update (Make the RF choke OUTSIDE !!!).d20070930-t114048, DG2IAQ-Mods von 31354427, MFJ-935B [ Pobierz całość w formacie PDF ]
Hi.I did a mistake on doing my postings + pictures !As you can see I built in a RF choke on a FT140-77 core inside the MFJ-935Bto suppress RFI on the outer shield of the coax cable. This was a mistake,as the RF only can be blocked while RF of the inner AND OUTER (wire + shield)has to go through the choke core.But if you build in the core into the MFJ-935B case then you have one GNDconnection at the input and another GND connection at the first variablecapacitor.This means the RF on the shield (GND) can go around the FT core and stillcan stray into the shield of the coax cable at the TRX socket !!Solution:--------------You do NOT HAVE to build in a RF choke into the MFJ-935B case. Just removethe single wire and replace it with a piece of coax cable, like RG58, RG213,or like I did with AIRCELL-7.! ! ! ! ! ! ! ! ! !But put the RF choke on your OUTER coax cable to the TRX instead !!!!! ! ! ! ! ! ! ! ! !I use 2 RF chokes. One on the MFJ-935B side of the coax cable, another onedirectly at the TRX side. This gives the best suppression on any circumstances.Sorry for the faulty pictures. I will fix that in my future and officialmodification sheet, of course.Best 73,Jochen (DG2IAQ) [ Pobierz całość w formacie PDF ]