[Elecraft] K2 RF Detector

[Don Brown]

Hi

If the K2 will work properly with the KPA100 removed and the DC voltage is back on the VRFDET line then you may have a bad U6 in the KPA100. This IC is a tristate op amp and if bad will load down the VRFDET line. I have found several of these IC's bad with the symptoms you are describing. The IC can be zapped if a greater than 5 volt signal is applied to the VRFDET line. This could be caused by a miswired 9 pin D RS232 or data connector or by static discharge. It may be a good idea to add a couple of diode clamps to the VRFDET line on the KPA100 to protect this IC. Maybe Wayne should give us some direction here. 


Don Brown  (the other Don)

KD5NDB
  ----- Original Message ----- 
  From: J F<mailto:phriendly1 at yahoo.com> 
  To: elecraft at mailman.qth.net<mailto:elecraft at mailman.qth.net> 
  Sent: Saturday, July 31, 2004 5:50 AM
  Subject: [Elecraft] K2 RF Detector


  I've moved along, (thanks Don) with my problem. It
  looks like I have a RF voltage at the input of R67
  (1.5K 1%) but nothing on the other side. No DC voltage
  at D9. What should I be seeing in this area. I was set
  for 2 watts or a bit less...
  Thanks,
  Julius 
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