[Elecraft] K2 alignment confusion...

[Don Wilhelm]

David,

Don Brown has already given you some good leads - here are my additions:

What you are saying is that your K2 has little or no power output - a 
reading of 0.1 or 0.2 watts really means no power output because that is 
the lowest indication that the microprocessor is programmed to indicate.

You can do the checks in the 'troubleshooting section' by trying the 
things listed, but I suggest that you page forward to the 'Transmit 
Signal Tracing' section beyond that chart and use the RF Probe (the 
parts are provided with the K2 kit, so if you have not built it yet, now 
is a good time).

If you have no power output, the RF voltage readings that you measure 
when following the steps in transmit signal tracing will be *higher* 
than the 'expected' value - *until* you get to the stage that is 
failing.  Once you come to the point where the RF voltage is 
substantially lower than the expected value, stop, for you have 
identified the failing stage and troubleshooting that one stage for the 
problem is easier than guessing about the entire transmit chain.

If instead, you want to just 'shotgun it', then you should check all 
components in the transmit section for proper values, good soldering, 
and good tinning of all the toroid leads.

While it is possible that one of the transistors is not working right, I 
must point out that is a rare thing - most problems are first soldering, 
followed closely by improperly prepared toroid leads.

Sorry I could not respond sooner, but I have other irons in the fire 
here too.

73,
Don W3FPR

dking at vcn.com wrote:
> I am at the 40-meter transmitter alignment stage in Alignment and 
> Test, Part III.
>
> It instructs me to "Place the K2 into tune mode and activate the 
> built-in wattmeter by holding "TUNE".  Using the alignment tool, 
> adjust L1 for maximum output."  And, do the same with L2, etc. etc. etc.
>
> First, I'm going into a 50W dummy load/Wattmeter (MFJ 267).  And I 
> have my Cal Curr setting at 2.0, and Power is set to 2.0 as well.  I 
> also have the radio set to 7100  for freq.
>
> When I put it into Tune mode, I get a reading of "P. 0.2" or P. 0.3 
> through 0.4  It will flicker back and forth across those three values 
> whether I turn the tap on L1 or L2 or just leave it completely alone.
>
> At the "info triangle" at the start of this section, it says "you'll 
> place the K2 into TUNE mode by holding TUNE."  However, if you "hold" 
> the button in it makes no difference from what happens if you just 
> hold it in long enough to activate the P. 0.2 (etc.) display....
>
> I do not have a key plugged in, so I obviously am not keying anything 
> at the time of tuning...but it did not state you needed a key 
> attached, and I presume putting it into Tune mode is "keying" the 
> radio anyhow....which may be an incorrect presumption...heck if I know.
>
> I went into the trouble shooting section, and it appears I need to be 
> looking at Problem 150 through 160....
>
> The resistors are correct, the Diode appears to be correct (so small I 
> can't read any numbers on it, but it checked out at the time of 
> installation and is oriented correctly.,  I've not been able to find 
> any shorts, the Transformers T1-T4 are wound as per part III of the 
> assembly section.
>
> I've not checked the DC voltages because I cant' find in the manual 
> what they should be reading or whether to check with power on or off 
> and have reached the end of my patience for the evening and am not 
> certain I'm even on the right path...
>
> Any direction would be appreciated.  This build has checked out on 
> every step to  date...but I'm stumped.
>
> David King
>
>
>
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