[Elecraft] K2 Finals - Chronic Blow-Outs

[Don Wilhelm]

Ray,

Even though you have changed Q11 and Q13, do check the voltage at the 
base of Q7 or Q8 both during receive and transmit.  It should be zero 
during receive and close to 0.6 during transmit.
If that voltage is something different, you will need to look for the 
reason before installing (and blowing) another set of PA transistors.

Thanks for the good words on the KSB2 option.  You can always tell one 
of my KSB2 builds at a glance from the top.  I ground the filter 
crystals near the bottom of the crystal cans instead of on the top.

73,
Don W3FPR

On 10/13/2012 9:08 AM, w7asa wrote:
> Man!  You guys are really encouraging-and FAST!
>
> The K2 has ONLY the SSB option at this time. I am building the ATU, 160,
> 60m, and a few more goodies on my bench as we speak.
>
> ---
>>>> I bought this on the internet very recently and have basicaly no
>>>> information available from the seller. When I ordered the ATU kit from
>>>> Elecraft, I also ordered two K2PAKIT packs just in case, *figuring that
>>>> I would never need them*
> I installed all K2PAKIT components, including Q11 & Q13, and the 1.5 Ohm
> resistor R50. My bench has a grounded ESD mat and wrist strap and I've made
> a career working to IPC610/620 and mil electronics standards. So, I am
> really comfortable inside of this radio.
>
> The general workmanship on the main board was not very good but I am told
> that it was functioning for years.  After I have it running,  I intend to do
> a lot of flux removal, reflow & rework to clean it up.  However the SSB unit
> *is really excellent*: shiney joints, no voids, great fillets... so I knew
> that it was built by someone else as soon as I saw it. I found paperwork in
> the maual and the EXCELENT SSB board was made by Don Wilhelm!  Great Work
> Don!  Rest assured, I used to do a lot of nit-picky QA & rework for DoD and
> even through my magnifiers, your SSB board is really superb work ! ...
> small world, eh? (and no, I do not work for Don...)
>
> Thanks for the settings and reading info. I will do the current, bias
> voltage and settings checks as indicated by you guys and thanks for the
> direction.  I am brand new to the K2. My next two replacement parts kits are
> ETA next week, so I have plenty of time to snoop, measure, poke & prod until
> then, but I'll go straight for the settings - being the low hanging fruit.
>
>
> Thank You & I'll keep you posted -
>
>
> 73 de Ray
> W7ASA ..._ ._
>
>
>
>
>
> --
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