K1-4, Low Power on 1 Band only

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K1-4, Low Power on 1 Band only

Randy Tompson
Thanks for any advice anyone can give me.  I'm certainly no EE....  I've
reviewed the past couple of years of archives for this reflector, and
haven't found my exact problem spoken to.

I purchased a K1-4 on eBay, and find it has sufficient power on 3 bands,
but low power on 1 band.  My seller says he'll stand behind the sale, that
he was unaware of the problem (didn't use 30 meters).

mHz       Power out (OUT set for 5.0 watts)
====    =============================
7.075             5.0
10.075           1.3   (transmitting into an Elecraft DL1)
14 .075          5.0
21.075           3.8

I have good audio volume on 30 meters.   Power output is correct for OUT
settings below 1.3 watts, limits out at 1.3 watts for OUT settings above
1.3 watts.

Each of the tests I've run already has failed to isolate a problem:

a.  Correct capacitor value markings on C22 thru C34

b.  Correct # turns on L4, L5, and L6

c.  Visually inspect solder joints, L4 thru L6, C22 thru C34, C1 thru 6, CA-CH.

d.  Continuity/solder connections L4, L5, L6

e.  Correct 30 meter crystal value markings.

f.  Visually inspect 30 meter crystal solder joints, crystal can ground
solder joints.

g.  Peak 30 meter filter trimmer caps (C5, C6, CE, CF) while transmitting
at OUT = 2.0 watts.

Again, thanks in advance for any advice...

Randy Tompson
WA4CIT
K2 1086    K1 85     K1-4 1505 (on 3 of 4 bands)

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Re: K1-4, Low Power on 1 Band only

Don Brown-4
Hi

It seems I have run into this when the trimmers are peaked out of sequence. The bands are set up as sort of a master/slave arrangement so it is important to set the correct band first before doing the next. You must follow the peaking procedure exactly in order as listed in the manual. In your case make sure C5, C6, CE, and CF trimmers are peaked on 30 meters first then C7, C8, CG and CH are peaked on 40 meters.

It is also possible to set the peak on receive to two places. One on the correct frequency and one on the image frequency on some bands. If the peak is set on the image the receiver will appear to work but the transmitter will not work or have low output in that band. If that is the case it may be better to start over and set all of the trimmer slots parallel to the flat side on the trimmer and repeat the  alignment on all of the bands.

Don Brown


  ----- Original Message -----
  From: Randy Tompson<mailto:[hidden email]>
  To: [hidden email]<mailto:[hidden email]>
  Sent: Wednesday, July 14, 2004 7:57 PM
  Subject: [Elecraft] K1-4, Low Power on 1 Band only


  Thanks for any advice anyone can give me.  I'm certainly no EE....  I've
  reviewed the past couple of years of archives for this reflector, and
  haven't found my exact problem spoken to.

  I purchased a K1-4 on eBay, and find it has sufficient power on 3 bands,
  but low power on 1 band.  My seller says he'll stand behind the sale, that
  he was unaware of the problem (didn't use 30 meters).

  mHz       Power out (OUT set for 5.0 watts)
  ====     =============================
  7.075             5.0
  10.075           1.3   (transmitting into an Elecraft DL1)
  14 .075          5.0
  21.075           3.8

  I have good audio volume on 30 meters.   Power output is correct for OUT
  settings below 1.3 watts, limits out at 1.3 watts for OUT settings above
  1.3 watts.

  Each of the tests I've run already has failed to isolate a problem:

  a.  Correct capacitor value markings on C22 thru C34

  b.  Correct # turns on L4, L5, and L6

  c.  Visually inspect solder joints, L4 thru L6, C22 thru C34, C1 thru 6, CA-CH.

  d.  Continuity/solder connections L4, L5, L6

  e.  Correct 30 meter crystal value markings.

  f.  Visually inspect 30 meter crystal solder joints, crystal can ground
  solder joints.

  g.  Peak 30 meter filter trimmer caps (C5, C6, CE, CF) while transmitting
  at OUT = 2.0 watts.

  Again, thanks in advance for any advice...

  Randy Tompson
  WA4CIT
  K2 1086    K1 85     K1-4 1505 (on 3 of 4 bands)

  _______________________________________________
  Elecraft mailing list
  Post to: [hidden email]<mailto:[hidden email]>
  You must be a subscriber to post to the list.
  Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft<http://mailman.qth.net/mailman/listinfo/elecraft>    Help:  http://mailman.qth.net/subscribers.htm<http://mailman.qth.net/subscribershtm>
  Elecraft web page: http://www.elecraft.com<http://www.elecraft.com/>
_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft    Help:  http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com