[Elecraft] VCO Voltage Checks - 40m

[David Wilburn]

Ok, thanks.  I will take a look around later today.  I did not see 
anything else "go" at the time.  Man, and I thought I felt bad before 
you email.

***Yes***, the note about changing the menu is in there.  ***So the 
fault is mine.***

I did all the rework eliminators requirements on page 59.  I had a note 
in the alignment page about checking the rework eliminators 
documentation.  When I went to their page, I did the installation of all 
the connectors and such and thought I was done.  I then saw the note in 
the Alignment section, and assumed (yea, I know what it means) that it 
was referring to the headers I had just installed.

So to reward everyone's (yours, Gary, and Ken's) efforts to make the 
rework eliminator's product more idiot proof, I have invented a better 
idiot.

David Wilburn
dave.wilburn at verizon.net
K4DGW



Don Wilhelm wrote:
> Dave,
> 
> I do not have enough data to tell you whare to start on the current problem.
> Check voltages and look for charred components or burned PC board traces.
> Be certain the 8 volt regulator on the control board is supplying voltage
> and follow its path onto the RF Board.
> 
> On your 'original problem', you apparently have installed the "Rework
> Eliminators" and I must offer yet another RANT:
> 
> You may not have fully followed the instructions that came with the 'Rework
> Eliminators'.
> My beef with the rework eliminator folks is that this one item is SO VERY
> important and they apparently still do not put it in big bold warning
> letters.
> 
> When you change C71 to 120 pf in the VCO area you must enter the secondary
> menu and set D19 - y.
> 
> But also keep in mind that with the 120 pF value at C71, your VCO voltage
> range can no longer be completely tested - the lowest voltage will now occur
> on 60 meters at 5300 kHz, so you will have to remember to revisit the VCO
> voltage alignment after the K60XV is installed.
> 
> The K2 manual is quite correct in saying that none of the K60XV parts should
> be installed until after the K2 has been completed and aligned.
> Unfortunately the K60XV part of the Rework Eliminators is NOT, I repeat NOT
> 'plug and play'.
> 
> About 6 months ago I had several email exchanges with Gary H. about this
> problem, and at one point he said something would be done about it, but
> still this matter crops up over and over again, so I can only assume that it
> has not been corrected in their documentation with adequate warnings.
> 
> In other words Dave, the Rework Eliminators have broken your K2 by causing
> you to try to correct a problem where there was none.
> 
> RANT off.
> 
> 73,
> Don W3FPR
> 
>> -----Original Message-----
> 
>> While troubleshooting the "original problem" below, I was making
>> changes, powering it up, checking, powering down, making changes, and at
>> one point I had the radio off but 12v still on and connected.  I decided
>> to re-flow the connection at the junction of C68 where it connects to
>> R17.  There was a small spark, I stopped, turned off power, and
>> disconnected it.
>>
>> On the next power up I had an Info message.  I did not hear any relays,
>> I think it may have been info 080, but not sure.  I got the same message
>> (what ever it was 080, 108, or 118) on the next power up. I cycled power
>> again, and the relays kicked and I got the Elecraft display.  Now the
>> voltage reading for ALL bands is 7.94.  It seems the instant grounding
>> of the input of Q18 (with my ***verified*** grounded soldering iron) is
>> not desirable.  And just to make it interesting, when ever I figure out
>> what gave way to the instant grounding, and get the part(s) in on-site,
>> and re-installed, I will likely have the "original problem" there
>> waiting for me.
>>
>> Seems to me I read somewhere that you shouldn't stay after it after
>> getting tired, cause you will make bad decisions.  Seems to me, it was
>> even mentioned in a discussion with NU4I (Ken Moorman) today on the
>> phone.  Some people's kids, they just don't learn.
>>
>> Original problem
>> =====================================================================
>> The voltage readings for 7000/7300 are 7.92.  It is not much above the
>> window of 7.5, but they do not vary with frequency as the others do.
>> All other voltages are well within tolerances.  Adjustments to L30, do
>> not change the voltage on the 7k range of frequencies.
>>
>> I have installed D19, and D20, and C71 is a 120pf cap.  They are part of
>> the rework eliminators supplied items.
>>
>> I have verified C71-C74, and D21-D26.
>>
>> I have re-flowed all the solder connections associated with K13, K14,
>> and K15, and most of the surrounding circuitry.
>>
>> Band	Low Freq	Voltage		High Freq	Voltage
>> ====	========	=======		=========	=======
>> 80m	3500		2.308		4000		5.99
>> 40m	7000		7.94		7300		7.94
>> 30m	10000		3.120		10150		3.677
>> 20m	14000		2.587		15000		4.27
>> 17m	18000		3.333		18200		3.539
>> 15m	21000		2.482		21450		3.656
>> 12m	24800		4.22		25000		4.61
>> 10m	28000		3.512		28800		4.39
>>
>>
>> --
>>
>> David Wilburn
>> dave.wilburn at verizon.net
>> K4DGW
>>
> --
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> 11:55 AM
> 
>