6 Photos - May 24, 2013
Photo: Under the lid, pardon the poor lighting, I'm using my point-and-shoot from the early 2000s.  Power supply in the top left and top center, audio stages on the left, VFO (PTO) in the center, IF stages in the bottom right, and finals cage in the top right.  The two round plugs on the VFO are for adjusting linearity -- it can be zeroed every 50 kHz across the 1 MHz dial scale, for an ultra-linear and accurate readout (for the time).  Finals are a pair of 6550s in AB1.Photo: Central Electronics 200V 100 W AM/PM/CW/SSB transmitter from ca. 1960.  Note that there's no final tuning controls; it's tune-less!  Just twist the VFO and hit the key.  The white circle in the upper right is an oscilloscope, used to monitor transmission quality on the air.Photo: There are a number of "set and forget" controls behind the signature CE magnetic covers on the front.  These controls are intended to be set once and then readjusted rarely, if ever, unless the rig is moved to a new operating position or key components are replaced.Photo: That's a lotta plugs!  This unit has the AT-100 factory accessory on the far left -- it's a five-band antenna switch ganged to the band switch on the front of the unit.Photo: Finally, the under-chassis.  The finals and IF stages have a shield that's (obviously) not removed for this shot.Photo: Output on 80m!  The trace isn't calibrated (it's using a simple capacitive pickup in a bud box from radio shack), but the key is that the waveform is clean.  The spectrum analyzer (under the scope) showed no harmonics, and the scope shows no AF noise on the carrier.  Score!