[Elecraft] K1 Alive Sans 20 Meters Followup

[Don Brown]

Hi

The k1 trimmers can sometimes have a peak at two places on some bands. One at the correct place and another at the image frequency. If you set it on the image frequency the receiver will work but not the transmitter. This is a common problem to set the trimmers on the incorrect peak. When you rotate the trimmers and then reset them you likely found the other peak. I use a WM2 wattmeter on the 100 mw scale to look for the correct peak. The 100 mw scale is one of the reasons I like my WM2.  When the trimmers are out of sync you will see the needle just move on the low scale when one of the trimmers are adjusted. When I find the little peak I then go to the other trimmer and switch to the 10 watt range on the WM2 and bring up the output. The trimmers interact so one can mask the other. I have "fixed" several K1's with this problem for other people. If a K1 works on one or two bands but not on the others then this most likely the problem.

Don Brown


  ----- Original Message ----- 
  From: John J. Bahun<mailto:jbahun at earthlink.net> 
  To: Tom Arntzen<mailto:tom.arntzen at monet.no> ; elecraft at mailman.qth.net<mailto:elecraft at mailman.qth.net> 
  Sent: Sunday, June 06, 2004 6:04 PM
  Subject: Re: [Elecraft] K1 Alive Sans 20 Meters Followup


  Well......

  After a very late night (3 AM) of studying the schematics and proving to
  myself that the xtal was alive and well and the relays were fine, I
  concluded that their had to be something going on with the Trimmer caps.....

  I got your suggestion to rotate the caps 10-20 times and I first thought
  that sounded kinda crazy - but - at this point after checking the trimmer
  installations and finding no problems - what did I have to lose?

  After rotating the trimmers a bunch of times - Whammo - Peaking was there
  and now have a solid 5 watts on 20 meters!

  Not sure exactly what was going on with the trimmers for sure - I did not
  overheat them when I soldered them (I use a Haeko Temp controlled station) -
  But - It works!

  Any explanation on exactly what was going on with the trimmers?

  Thanks again and now on to the ATU build!

  73 - WB8UFA / 7