Thanks Ron, Takes me back a LONG time ... Was R/O on several USC&GS/NOAA ships and "hung out" at WPD in Tampa. Lots of 400 - 500 kHz time. Tx was a TBL with M/G set in the "basement". (:-) Anyone know where I could find an RCA 8506 ... or an 8510? Or the Mackay equivalent/s? Google doesn't even turn one up! 73! Ken Kopp - K0PP k0pp at arrl.net