Most could probably work this put from context clues, but for clarity:

Original : “Hey y’all, check out the new and improved 147.27 on poor mountain.  It’s S9+10  at my qth.
Great job guys”

Translation: “Hey everyone, check out the newly upgraded radio repeater on 147.27 MHz located up on Poor Mountain. The signal coming into my house is exceptionally strong and crystal clear. Great job to the crew who worked on it!”

Jargon Breakdown

147.27: This is the specific radio frequency (147.270 MHz) on the 2-meter VHF amateur radio band.

Poor Mountain: A prominent mountain ridge near Roanoke, Virginia. It is heavily used as a site for commercial, broadcast, and amateur radio communication towers. The message refers to a radio repeater located on that mountain. A repeater receives a weak signal from a handheld or mobile radio and retransmits it at higher power from the mountaintop to cover a massive geographic area.

S9+10: This is a signal strength report. On a radio’s “S-meter,” signal strength is rated from 1 to 9 (with 9 being a perfectly strong, crystal-clear signal). When a signal is incredibly powerful, it goes “over 9” and is measured in additional decibels.

“S9+10” means the signal is exceptionally strong and perfectly clear- 10 decibels louder than a standard “strong” signal.

QTH: This is an old telegraph “Q-code” that means “my location” or “my home station”.