I think it reduces your output so you can drive a transverter.
----- Original Message ----- 
From: "Tom Behler" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Saturday, September 29, 2012 12:17 AM
Subject: Beware of the DRV Function On The TS590


> Hello, all.
>
> What I'm going to share here may not be big news to some, but for those 
> like
> me who never had this problem, it is a bit disconcerting.
>
> Tonight, I decided to fire up and get re-acquainted with my TS590, since I
> probably hadn't even turned it on for a month and a half.  I had taken 
> some
> SWR and output power readings using the rig's  internal meter, and
> everything looked great, until I tried getting on the air.
>
> Even if I was on a resonant or near-resonant frequency for one of my
> antennas, the rig's auto-tuner would not tune.
>
> I played around for quite a while, trying to figure out what was wrong, 
> and
> then, I decided to swallow my pride, and ask the sighted XYL for help.
>
> It turns out that I inadvertently had activated the DRV function.  This
> happens when you press the meter function button down too long.  The meter
> switch is one of the few buttons that doesn't talk on the rig, so it's 
> very
> easy to make this mistake.  Once the meter switch  button was re-set to
> normal, everything was fine again.
>
> Does anyone know what the DRV function is, and has anyone ever used it?
>
> Just curious.
>
> 73 from Tom Behler: KB8TYJ