If your ammeter isn't deflecting as much as it normally does, that's a good indicator that the power out is lower. You must be getting out somewhat because you're
email is working. I'm not familiar at all with your transceiver, but when you tune up, most rigs do that at reduced power. Do you have an RF power adjustment on the radio? Is it
SSB only or does it do AM as well? If so, when you key the radio in AM mode, you'll see a full power carrier whether you're speaking into the mic or not. Have you tried it using voice? You'll only see power out when you are modulating while transmitting on
SSB. Try making a call on SSB voice and see if the power out is what you normally expect. It's possible your SCS TNC needs to be configured to increase the tx audio level. I would look at the configuration of the TNC first since you mentioned it was recently updated, especially if it started at that time. Your transceiver may have a tx audio adjustment for the data port that your TNC connects to as well. Most of these settings look like they would be menu accessible on your radio, if at all, and not likely to have been bumped or nudged out of whack. Lastly, are you sure the tuner is tuning properly? Good luck.