Last night, we had our monthly AM net on 145.7 Mc. Prior to the net, I got into a round table on 147.54 FM. One of the stations was almost 70 miles away, and crystal clear, running modest power. We had 7 locals on the net, and immediately after the net, I saw my receive meter go up to 3 (out of 10). I didn't hear any audio, so it was likely someone transmitting in FM. It wasn't long enough for me to tune him in on my AM receiver. So whilst I was taking everything down, I plugged an FM transceiver into my other antenna, and listened to both radios (AM and FM) on 145.700. Sure enough, a station from 60 some miles south (Chicago area) is asking about our net because he never heard it before. He said they have an Echolink node on that frequency, and thought we might be using it because he could only hear two of us. I don't have much of an idea how such an Echolink node works. I told him that if we were interfering, I'd consider moving our net. He said it's not a problem because he normally doesn't hear us. He has a nightly sked with someone on that frequency an hour after our net. He said he found it interesting that we were there running AM, and enjoyed listening. Normally when there's a band opening, there are a few other AM guys to the north and to the west that will check in.