<Think how "clean" a well built 12kw would be at 1500 out.??
<Don W4DNR
That would be like running a SB-220? at? 150 watts pep out.....wasted effort really.?
To run that amp at reduced power, the B+ needs to be reduced by using the lower taps on the sec of the plate xfmr.? ?Then the plate load Z remains the same.?
IE:? use the 2900 V tap...and drive to 1/2 normal plate current.? ?PO is now 3 kw.? Or use the 2300 V tap for even lower PO.?
With the Dayton blower used, and a 25 deg C (77F) inlet air temp, the CCS anode diss is 8 kw.? ?The blower is a 2 x speed type.? ?The lower speed is more than ample for SSB / CW use.? It also has a switch on the front panel to change blower speeds.? The front panel was powder coated.? The socket, tube, chimney and fil xfmr were all brand new.? The only thing used was the pair of Jennings vac tune + load caps...and variac for the fil xfmr.? All 4 vac relays are sped up with an overvoltage.? It's the same amp that I posted 57 pix of, years ago on the old yahoo? group.? When it switched to groups.io? the pix were not transferred over to the new group.? It's also got a new hr meter to keep track of hrs on the fil.? In normal operation, the 7.0 vac fil was reduced to just 6.3 vac (after 200 hrs @ 7.0 vac).? Bucketloads of emission. On paper, the tube should last 35k hrs.? Tube is rebuildable.? Tube is rated for 3.5 amps CCS.? In normal operation it was 2.1 amps? for 10 kw...and? 2.5 amps? for 12 kw.?
It's built like a fn tank.? ?It rolls around on steel casters.? Footswitch plugged into the amp, so it could be keyed from the garage for tune up.? In normal operation, all the various freqs for each band were logged on a cheat sheet, for both the output and the input. So it was just....'dial it up by the numbers' after that.? IE: dial up pre-sets.? ?Took 45 secs to get from 15m down to 160m.? Good enough.? It's a 24" wide rack.? ?Plate xfmr is 253 lbs.? Forget what the total weight is, I think around 400 lbs.??
