Another Question

[K4KGW]

Assuming your wattmeter is OK, it should read whatever the rated power output of the transmitter is when it is fully loaded (to 250 ma. or whatever the book says), either in the AM mode without modulation, or in the CW mode.  I am not familiar with your particular transmitter, but if it has 2 6146 finals, you should be able to run it at about 150 watts INPUT on CW, and about 120 watts INPUT on AM.  Assuming 75% efficiency for your Class C finals, then your OUTPUT power on CW should be about 112 watts, and on AM with no modulation, about 90 watts.

If your rig uses high level plate modulation. the symptoms you describe may be an indication of soft finals.

73,

Keith

reds1964 wrote:

> Hello All,
>
> I have a question about power output from an AM transmitter as read on a Heath HM-102 wattmeter. When I turn the transmitter on in the AM mode the wattmeter shows 10 watts with no modulation. With modulation the wattmeter kicks up to about 20-25 watts. This is supposedly a 100 watt transmitter. I am assuming that the HM-102 is a peak reading wattmeter,so is the 25 watts my actual output power,or is it some multiple thereof, or in other words, would my power output with 100% modulation actually be 100 watts,PEP? I forget how to figure PEP so maybe you guys and gals can remind me. On the CW mode I get about 50 watts,but I have normal plate current 250mA or a little less since that is the max value for the 6146's, drive level is entirely sufficient,even over sufficient as I have to lower it a bit most times, so why don't I get the full 100 watts? I am using a dummy load for testing, the dry variety. So,do I need new finals, does my wattmeter need adjusting, or do I need to stop asking stupid questions? By the way, the transmitter is the Knight T-150A. Hope this doesn't open another can of worms about this particular transmitter.
> Any help would be greatly apprecitated.
>
> 73's
> Carl
>
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