Kevin Raper wrote: > Has anybody tried the Penta Labs 4CX400C tube? It is Supposed to be a Direct Plug-In Replacement for the 4-400C. > I am looking at a set for an RCA BTA-1R1. Why not buy a new 4-400C? see: http://www.rfparts.com/tubetran.html 4-400C TAYLOR $179.95 -- Ron KA4INM