[Heathkit] Heath AT-1 info

[Edward B Richards]

Hi Van;

Sounds like a matching problem. Not loading right. What is your SWR?
Check PA for wiring errors, shorts, opens, solder splashes, lose wire
ends, etc. Especially the loading capacitor. Good luck.

73, Ed Richards K6UUZ
Simi Valley, Ca 93065
Home of the Air Force 1 pavilion

On Sun, 1 Oct 2006 00:15:17 -0700 "Van K7VS" <wa7fab at cdsnet.net> writes:
> 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) 
> 
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