Tom,
Reconnect the rig to the Astron and read the output voltage with the 
rig "key down".  See if it is about 13.8 vdc.  I didn't have a chance 
to respond to your post when you noted trying a 12v battery.  My 
experience here with a 12 volt battery was lower output from about 
everything I used it with.
Congratulations.
Pat, K9JAuAt 04:32 PM 12/24/2007, you wrote:
>Hi, all.
>
>Believe it or not, I think I've found the problem with the low output power
>on my IC746.
>
>Based on a comment I read in a E-ham review, I connected the Ic746 up to the
>new Samlex 35-amp power supply I got for my new TS480, and guess what:
>Output power was within a watt or two of 100 watts on both my talking sWR
>unit, and on the radio's power meter when connected to a resonant antenna
>with a 1.1 to 1 SWR reading.
>
>So, now, I'm thinking something might have gone south on my old dependable
>Astron RS35 power supply that might be giving the rig insufficient power
>voltage or something like that.
>
>Has anyone heard of similar results?
>
>Merry Christmas to all on the list, and thanks for putting up with this
>latest round of troubleshooting efforts.
>
>That's the life of we hams--always something to challenge us.
>
>73 from Tom Behler:  KB8TYJ