[Elecraft] Hum coupling?

[Don Brown]

Hi

The K2 is susceptible to hum pick up. You must keep all sources of AC magnetic fields at least 3 feet away from the K2 or the VFO will be modulated by the hum. This has been noted many times here on the reflector. Even a high intensity lamp too close to the K2 was a problem. Do not stack the K2 on top of a power supply or amplifier or anything with a large power transformer


Don Brown

KD5NDB


  ----- Original Message ----- 
  From: Tom Althoff<mailto:althoff at verizon.net> 
  To: Elecraft at mailman.qth.net<mailto:Elecraft at mailman.qth.net> 
  Sent: Thursday, October 28, 2004 4:13 PM
  Subject: [Elecraft] Hum coupling?


  Ten-Tec recommended putting the matching speaker/power supply of my old Omni-V on the RIGHT hand side of the radio.  The audio lines ran on the left side and the transformer in the supply caused hum on receive.

  I'm experiencing similar AC hum on the K2 audio.   The K2 sits on top of my Titan II and when the HV is set to operate (kicking in the big HV xfmr directly under the K2) I get the hum.  If I pick the K2 up and move it about 3" away from the Titan then all is well.

  Has anyone else experienced hum from nearby power transformers?   I plan on using a 10Amp analog supply (not here yet) and anticipate I might have to keep it away from the K2.   I suspect switching supplies do not cause the same effect.

  Tom K2TA
  Greenwood Lake, NY
  K2 #1117
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