I bought a used ICOM IC-2710H on eBay. The owner's manual calls for a HM-98 mic. The ICOM mic that came with it doesn't have a model number on it, but I subsequent learned there's a plastic cap (which I didn't receive with the rig) that has the model number on it, and I am suspecting that it is actually a HM-98S because it won't key the rig.
I've read the 2004 postings at http://www.eham.net/ehamforum/smf/index.php/topic,63133.0.html
, which seem to have some bearing on my present problem. I also have seen another discussion athttp://forums.qrz.com/showthread.php?327332-Icom-HM-98-vs-HM-98S
I have a HM-133 that came with my IC-208H rig, and it works on the IC-2710H - but with high deviation. I wonder if there is a modification of either the IC-133 mic or IC-2710H rig to adjust the high deviation problem. N3MX seems to say in the 2004 eHam discussion above there's no potentiometer in the rig itself. Thanks and 73 - George, N9EJS