Output pwr foldback with 1.7 to 1 SWR, Flex 6500 and SmartSDR 1.11.12

Bill Speedie

The power output of my 6500 seems to fold back, as shown by reduced current draw on my power supply.  I'm using a 6500 with PSDR 1.11.12.  I disconnected the coax and used an SWR meter that shows a 1.7 to 1, not great but not so bad that I would expect the radio to object.  Am planning on taking down my dipole in the morning to see if I can detect any physical problem with it but wonder if someone has an idea why this is happening now where it didn't previously.  

Bill -VA3WTB

PSDR?

NX6D Dave

I think you probably mean SmartSDR 1.11.12.

What SWR does the SmartSDR meter show?

Also, this sort of problem can be caused by a high resistance in the power supply circuit that causes a low voltage condition at the radio's power terminals.  The output power will be correspondingly lower.

Jim Gilliam

RF on the shield of the coax, or RF in the shack, can cause not only erroneous SWR readings but erroneous operation of the transmitter. Be sure you are properly grounded and that your antenna has a BALUN at the feed point if the antenna is balanced. Make sure all your connectors are properly soldered.

Bill Speedie

Thanks, I'll check those things today. I do have a balun on the dipole, and yes, I was both sleepy and sloppy when I referred to PSDR, it's SSDR.  73, Bill -- KA6T

Larry _ NY8T

You should try one of the 2 programs (ddutil or frstack)  i know of that can read the dc voltage that the radio sees. I have had poor power pole connections at the back of the radio that caused low power output. In my experience with a 6500 and 6300 1.7 swr is not enough to roll back power.