copied from the Internet: From: morris@grian.cps.altadena.ca.us (Mike Morris) Newsgroups: rec.radio.amateur.misc Subject: Re: BNC connectors for ICOM HTs keenan@girtab.usc.edu (Robert Keenan) writes: >>Does anybody know where I can get a chassis mount BNC connector WITH >>A DOUBLE D cut on the threads? This is for an ICOM H2 radio. >>Everybody sells it with only a single D cut. Thanks. >I have had this problem before. My solution was to get a connector with one >flat (Amphenol makes a good one) and file another flat on it until it will fit >in the hole. >I am not very impressed with the BNCs that Icom uses. They only have two >pins to contact the center conductor of the antenna, and it is easy for the >pins to get separated and not make contact. I have heard of this problem >a number of times, so I replaced mine as a preventive measure. The BEST replacement BNC connector that I have seen (and have used to repair the jacks on 3 different Icom radios) is made by Amphenol for Tektronix. They are not in any catalog I can find, and are not in the salesmans literature. I was told (after the salesman called the factory) that they are not available to the public unless you want to buy 500 of them. I've purchased them on a business trip to Portland (from the Tek Company Store - open to the public) and from the local Tek repair shop. They are very "tight" connectors - the antenna does not slop around, and the center contact has 4 gold fingers to grip the antenna center pin. They are not cheap - $4-5 each comes to mind - but the oldest one that I fixed is stil going strong after 3 years of _daily_ use. The hole in the metal chassis and the plastic case both have to be enlarged slightly, and the pc board will have to be releived a little. When you install the new connector throw away the solid wire that Icom uses to connect the PC board to the BNC center pin. Replace it with a piece of braid. I used a short length of the narrowest solder -wick I could find, but another friend used a small piece of RG-174 braid. It is 'way too wide, but it worked. You're after a flex connection between the board and the connector pin. It's a little tricky to make a connection with the solder-wick without filling up the braid with solder, but it can be done. Yes, the whole job is tedious, and you'll be swearing at the engineers when you are done, but the couple of hours the entire job will take is worth it. You'll need, besides common hand tools: The new connector - the one that I have left has "28JR200-1" stamped on it. When I picked it up from the local Tek fixer I I asked for a replacement BNC connector for a Tek scope. He didn't need a number or anything... Some white heat sink goop. There is no way that you will _not_ get some on your hands. ANd you'll want to put some back on the radio heat sink anyway - the three radios I've done the mod on have all been short on it. And the less there is the more the final will overheat 'cuz the heat can't be carried away. The small tube I picked up at Radio Shlock 3 years ago is still 1/3 full. A small piece of solder-wick type braid - the narrowest you can find. Buy a small roll - you'll need some to clean up the PC board where the old center contact is soldered and wired down. Small needle-point soldering iron - I use a Weller solder station with a 700-degree PTA tip. I should be using the next narrower tip but I damaged it a few months ago. Thin solder. I have a roll of .015" that I bought specially for doing fine work. It goes fast, but in compensation there is a _lot_ on a roll. A few drops of stiff Locktite or similar thread locking compound. I keep a small bottle of each of four different grades in my automotive tool chest - I've found I have much better reliability from my off-road vehicles when I use it on every bolt and nut - especially the distributor points. You will have to make your own thin wrench to get the nut on the connector off and the new one on. There is very little room in the radio to do this. I ended up ruining the hinge on a pair of cheap needlenose pliers doing the job. -- Mike Morris WA6ILQ ! This space intentionally left blank. ====================================================================== Note: I haven't tried or verified this, proceed at your own risk. WA2ISE /EX