What is it you ask?
Some super strong form of UV B rays that can penetrate through Mt. Everest? A planetoid with life forms in the shape of obese chipmunks? Or some podcaster's weird handle he/she uses?
That last one might be possible, just sayin'. ;)
If you've read my previous posting you note that this is going to be the name of my next podcast. Through that deduction you can figure out it is a number station.
And a right odd one at that.
It's been sending out signals into the stratosphere (atmosphere, -sphere) since 1982, according to observers (e2k site, Nexus @ the Centrifuge, Wikipedia - the Conet Project says it has been running since 1987 - booklet page 63. See it's a mystery!). This "oddity", as the e2k site labels it and others of the same ilk, has been running round the clock (The Conet Project booklet - page 14) with an EERIE sound that changes on the top of the hour (The Conet Project booklet - page 63, listen here - track 139).
This piece of mystery broadcasts about 40 km (or 25 miles) northwest of Moscow in a location called Povarovo in Russia (Wikipedia). According to the Wikipedia page there is no known purpose to the broadcast. The station has only broken it's, ummm, format three times in the past 28 years, the first in 1997. During this first break, a man speaking Russian gave the call sign and location solving at least one part of the puzzle. In 2002 and 2006 the voice returned, the last time he was a bit more busy with a longer message mixing numbers and the Russian phonetic alphabet (Wikipedia).
Someone on youtube caught a fourth voice transmission last year.