Find the manual here: http://www.qsl.net/tentec/manuals/229.pdf When I bought a used 229 a year ago, I grabbed this and printed it out. Imagine my surprise when the serial number that is hand-written on the document in the PDF matched the one on my tuner! Unless, of course, Ten Tec used the same s/n on *all* the 229s :-) 73 de chris K6DBG