I'd posit another theory...

Third, you had a slightly bad connection.  When you re-connected, everything 
was fine again.

----- Original Message ----- 
From: "Tom Behler" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Thursday, December 29, 2011 7:46 PM
Subject: Reduced TS590 Output Power Followup


>    Hi, all.
>
> Well, it has been a very interesting hour here, as I have tried to figure
> out what was going on with the reduced power readings I was getting with 
> my
> TS590.
>
> First of all, I want to say a great big thanks to Steve Dresser (WA1RTB).
> For whatever reason, I did not know that pressing the PF function button 
> for
> S meter readings when transmitting gives you the rig's output power.
> Knowing this, and using this function has made a world of difference.
>
> Before I say anythihng more, let me re-state that all power readings were
> taken with the rig's internal tuner off, the TX power control in the 
> highest
> possible position, and with my Tentech 238A manual antenna tuner in the
> bypass position.
>
> My first series of tests this evening involved taking power readings at 
> the
> resonant frequency of one of my antennas.  My output power readings with
> both the TW1 and the Rig's power meter varied anywhere from 68 to 80 
> watts.
> In all cases, I was using my Astron RS35 linear power supply.
>
>
>
> Then, I decided to switch power supplies.  I retrieved my Samlex 1235 
> supply
> from my RV, and tested things with that supply.  Again, for the tests, the
> conditions were the same with this new supply.
>
> When I took power readings this time, the rig's meter gave me a solid and
> consistent 100 watts.  The TW1 gave me readings that varied between 87 and
> 89 watts, but they were at least closer to being in the ballpark 
> especially
> when it is considered that the TW1 has about a 10% error margin.
>
> Then, I connected things back up to the Astron RS35 supply, and, for 
> reasons
> that I don't understand, I once again got consistent 100 watt readings 
> from
> the TS590 watt meter, and found the TW1 readings to vary from 81 to 89
> watts.
>
> As a result, I am coming to two conclusions:
>
> 1.  Either something is starting to get flaky with my 14-year-old RS35
> supply;  or
>
> 2.  When I did the tests with the Samlex supply, something might have 
> gotten
> re-set in the rig so that 100 watts now means 100 watts.
>
> Do any of these arguments make sense?
>
> Should I begin to get into the market for a new power supply?
>
> Just seeking some advice here.
>
> 73 from Tom Behler: KB8TYJ