[Elecraft] Fwd: K3/KPA500/KAT500 SWR problem

[Gary Ferdinand]

I’ll use the right email address this time :)



> From: Gary Ferdinand <gary at w2cs.net>
> Subject: Re: [Elecraft] K3/KPA500/KAT500 SWR problem
> Date: December 30, 2013 at 9:43:01 AM EST
> To: elecraft <elecraft at mailman.qth.net>
> 
> It  is my understanding that the KAT500 will monitor the VRFL and will fault to protect itself if it’s too high.  There are some impedances out there that the tuner can handle at lower power but simply cannot at higher power.  So, as you increase the drive, the VRFL ncreases and the KAT500 faults.  When the tuner faults, it no longer is presenting a tuned system to the KPA500, which then, in sympathy, faults and shuts down.
> 
> Since the (complex) impedance varies along the feed line, other feed line lengths might bring the impedance into a range the tuner can accept.  Of course when using a feed line to a multi-band antenna, this might just move the problem to another band.  But if it’s easy to do, try it.  Or, if you have something like a Rig Expert you can plug into where the tuner is and determine the impedance the tuner sees and use that as a baseline for any feeder length experiments.
> 
> Good luck and 73,
> 
> Gary W2CS
>