K2 - Day TwentyThree


I am trying to track down why my power output is low. I have a couple of hours into
this today... my vacation day (use it or lose it)





----Snip from the email that I sent to the
Elecraft Reflector----



K2 gurus:



I got a note from Gary (support) and Don (w3fpr) with some ideas.



--I checked the low pass filters and the number of turns.

--I validated that T4 is oriented the right direction --No burnt relays

--8R/8T are ~8vdc (R-7.87/T-7.815)

--8R on transmit goes to 0.245vdc

--I clipped W1 to test for PA feedback (no change)


--I removed the bottom panels and cleaned up a couple of joints as a CYA


--Removed and rewound LP for 80m


--Checked & resolder the connections of toroids for 20/30, 15/17, & 40


--Repeaked (on receive) all of the band pass filters with a signal generator


--Repeaked (on transmit) all of the band pass filters



I made some progress: (Original Test... and after some rework)

--Freq-----1 Test----1 Msg----2 Test----2 Msg

 3.750mhz  2.5w     
Hi Cur   2.3w      Hi Cur

 7.100mhz  6.1w     
Hi Cur   6.6w      Hi Cur

10.100mhz  0.3w     
Hi Cur   4.9w      Hi Cur

14.100mhz  0.3w     
Hi Cur   5.7w

18.100mhz  9.5w              
7.3w


21.100mhz  4.1w        
      5.0w

24.900mhz  0.5w             
 4.9w

28.200mhz  6.0w             
 6.3w



As you can see I am now getting ~5w on all bands except for 80m. I suspect
that the toroid cleanup might have been part of the answer for 20/30 and tweaking
the band pass brought 10/12 into better alignment.



On the three bands that I get a high current message it appears at the
peak power out and does go away if the power is reduced. Any chance that I am only
seeing power out of Q7 or Q8 instead of both of them?


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