[Heathkit] Heath AT-1 info

[Van K7VS]

Interesting:  I don't know if anyone else has actually spent any time using 
one but I have discovered the following:  Mine has 485 volts DC under load, 
key down and 535V DC key up.  Original iron vane meter shows 58 ma. into a 
52 ohm dummy load.  That amounts to 28 watts input.  Heathkit says in the 
older catalogs approximately 25 to 30 watts input.  However, one would think 
that you should see minimumly  50% effeciency.  Not even close!!  Using a 50 
watt slug thru my bird wattmeter I see 8 watts output.  I see 7 watts output 
thru my Waters Dummy load/wattmeter so will assume that the power is about 8 
watts out.  Now that is looking at minimum dip  of 58 mills into the dummy 
load.

What gives???  I have tried several 6L6 tubes and still see the same output. 
Have replaced all the old postage stamp mica's with new brown silver mica 
units and checked for loose grounds, tightened screws around the plate 
circuit where appropriate and so forth. And have plenty of grid drive using 
a PR crystal on 3650 Khz.

Still 7 to 8 watts output.  Does that sound right.  Has anyone else checked 
the output (not with a lightbulb!!) but with a reasonably well calibrated 
wattmeter?  Should I not get at least 12-15 watts output??

When I was a kid (14) and a novice I built one of these as was my second 
novice transmitter.  Admittedly, I lived in W1 Land (MASS) and worked 
stations all over New England and south in Virginia and West back around 
Indiana and Ohio so I know it worked pretty well.  But maybe I was one of 
the first QRPers!  Or anyone running an AT-1 back then was as well.  HI HI. 
Any comments about the output I am seeing would be appreciated.  Thanks. 
Van. K7VS (first licensed as WN1ZLK in 1953)