Mike,
The Viking II runs about 120 conservative watts, well 
modulated.  Uses plate modulation.  I've never run more than 200 
watts on A M with a Johnson Viking Valliant.  I have used the Viking 
with both my National and Collins receivers, and with many more in 
days gone by!  A M is fun and there are an interesting bunch of 
operators.  When I got licensed in 1957 A M was still rather widely 
used but sideband was coming on.  Many a battle was waged!
I had the A M gear back in the day and then went through another 
round more recently.  Still fun but I just don't have the room on the 
bench any more.  By the way, watch just above 29 mhz.  There is 
usually A M between there and 29.1 and your forty watts would do 
okay.  Lots easier than forty or seventy-five.
patAt 05:06 PM 5/5/2014, you wrote:
>Pat:
>
>What receiver do you use the Viking II with? Do you have an 
>amplifier to run a little heavy metal on A.M?
>I'd love to get into that, I listen to A.M every chance I get with my FT-102.
>Tried breaking in to a group but they didn't hear me as I was only 
>running about 40W, even though my rig is supposed to have 100% modulation.
>
>73:
>Mike VO1AX
>
>P S
>Are you the Gentleman I sold the Sure 440 desk mic to a number of years ago?
>I sold it to a guy on this list.