[Elecraft] KPA100 Rev D

[Don Wilhelm]

I was not annoyed, but wanted to produce clarity for everyone.  Sorry if 
I was harsh, I didn't mean it that way.
I do realize that the level of Elecraft gear can be confusing for those 
who do not work with it regularly.
I am here to help, not criticize, but to be clear we all have to refer 
to things by clear and unambiguous terms.

That is the price we pay for being able to upgrade our Elecraft gear to 
the latest level rather than buying an upgraded radio.

73,
Don W3FPR

On 3/31/2012 7:36 PM, Hisashi T Fujinaka wrote:
> I was just scolded for using the original poster's terminology (it's a
> KPA100UPKT, not a Rev D upgrade) but I'm glad Don finally answered my
> question about the shields.
>
> It's hard for regular people (i.e. everyone except Elecraft) to know
> about rev levels and which mod kits to order (I'd bet things work fine
> with none of the upgrades) so I'm sorry that I annoyed the people who
> know.
>
> Personally, my rig resets itself on 15M sometimes if I run>  90W so I
> had a real reason for asking about the shield kit. I seem to have the
> latest shield so that's not the answer for my problems.
>
> On Sat, 31 Mar 2012, Don Wilhelm wrote:
>
>> Folks,
>>
>> Before I get more questions indicating confusion, let me clarify in
>> detail --
>>
>> In my response below, I ignored the poster's reference to a "Rev D
>> Upgrade kit".  There is no Rev D KPA100 - the closest I can imagine to
>> Rev D is the manual revision, which is now Rev E.
>>
>> The manual's rev letter is not linked to the board version (either
>> populated or bare).
>> In this case, there have been only 2 versions of the raw KPA100 board -
>> the Field Test level, and all others.  There have been 4 versions of the
>> KPA100 - the Field Test version, then the first released version, and
>> then the version which incorporated KPA100MODKT, and lastly, the version
>> which incorporates KPA100UPKT.  This last mod kit has all the parts for
>> upgrading any level KPA100 to the latest.  If your KPA100 has blue
>> toroid cores at L16 and RFC1, you have the latest level.
>>
>> The shield is a different matter.  There are 3 levels of the shield -
>> the initial one with a wide notch at the SO-239 jack (about 1.4 inch
>> wide), then one with a more narrow (about 1/8 inch (3mm)) notch at the
>> jack, and lastly the addition of 2 solder lugs between the SO-239 jack
>> and the outside surface of the shield - this last shield also added a
>> shield for the speaker magnet since the magnet was sometimes responsible
>> for interfering with the operation of relays K13, K14 and K15 on the RF
>> board - some do it while others are just fine without the speaker shield.
>>
>> 73,
>> Don W3FPR
>>
>> -------------------------------------------------------------------------------
>>
>>
>> Syd,
>>
>> If your KPA100 has red toroid cores at L15 and L16, install KPA100UPKT.
>>   That kit will upgrade any level KPA100 to the latest.  If you do not
>> have a shield over the speaker magnet, add the KPA100SHLDKT as well to
>> upgrade your shield.
>>
>> Those mods will add significantly to the stability of the amplifier, and
>> I highly recommend them.
>> Those mods were specifically created to address a tendency to oscillate
>> a little above the 40 meter ham band under some conditions.  If you
>> operate with an autotuner  that tendency to oscillate is quite high.
>>
>> 73,
>> Don W3FPR
>>
>> On 3/31/2012 4:17 PM, Syd Smith wrote:
>>> I recently became aware of the Rev D upgrade kit for the KPA100 at
>>> Elecraft.  Where can I find a description of the changes and a
>>> recommendation of why I would want to install this kit in my Rev A
>>> amplifier which works FB.
>>>
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