KPA100 Upgrade Kit

[oe9fwv]

I have nearly built the KPA100 after manual revision C.
I have seen there is an upgrade kit that I ordered (but not received), and now I am
comparing it to the latest manual rev. E from January 2007.
I have seen there is  Resistor R33 1k, 1/2 W in the Upgrade Kit and the
resistor in the latest manual is 1/4 Watt. The same applies to R4, 100k.
Is this difference critical? In my KPA100 there is a 1/4 W resistor packed.

73! Werner oe9fwv

--
Dr. Werner Furlan
mobile: [phone]
fone: [phone]

_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

[Don Wilhelm-4]

Werner,

I do believe the 1/2 watt designation is a typo - I have not seen a 1/2
watt resistor as part of the upgrade kit.
Since you ordered the KPA100UPKT, send an email to [hidden email]
and ask for the 0.22 uf capacitor that is used at C31.  This capacitor
*should* be included with the KPA100UPKT, but unfortunately is not yet
added.  When you have the new capacitor in hand, remove the old C31 and
use the .22 uf in its place. (the KPA100UPKT tells you to update the
schematic with the new value, but it provides no other instructions.

As a reminder note to others (because I have been asked many times in
the past) - if you do not have the KPA100UPKT, please do *not* change
C31 - the new capacitor has a voltage rating that is OK for the new
design, but too low for the older design - it is not a separate mod, but
just a part of KPA100UPKT.

73,
Don W3FPR

Werner Furlan wrote:
> I have nearly built the KPA100 after manual revision C.
> I have seen there is an upgrade kit that I ordered (but not received), and now I am
> comparing it to the latest manual rev. E from January 2007.
> I have seen there is  Resistor R33 1k, 1/2 W in the Upgrade Kit and the
> resistor in the latest manual is 1/4 Watt. The same applies to R4, 100k.
> Is this difference critical? In my KPA100 there is a 1/4 W resistor packed.
>
>  
_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

[oe9fwv]

hi Don,

Don Wilhelm schrieb am 2 Nov 2007 um 19:01:

> I do believe the 1/2 watt designation is a typo - I have not seen a 1/2
> watt resistor as part of the upgrade kit.

you are right, it is mentioned in the KAP100 Upgrade Instructions Errata.
Rev. A-3 Dec. 4, 2006. I did not realise that there is an Errata document
before.

> Since you ordered the KPA100UPKT,
> send an email to [hidden email] and ask for the 0.22 uf capacitor that
> is used at C31.  This capacitor *should* be included with the KPA100UPKT,
> but unfortunately is not yet added.  When you have the new capacitor in
> hand, remove the old C31 and use the .22 uf in its place. (the KPA100UPKT
> tells you to update the schematic with the new value, but it provides no
> other instructions.

Where did you get this information? In my KPA 100 Kit C31 was 0.033 µV
and in the latest manual and in the upgrade kit diagram it is also a 0.033 µV  
(33N).

73!
Werner
oe9fwv

--
Ever stop to think, and forget to start again?


Email powered by Pegasus Mail free at <http://www.pmail.com>
Homepage: <http://www.qsl.net/oe9fwv/>
Fone [phone]
Fax [phone]
Mobile [phone]
Elecraft K2 #5203


_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com

[Don Wilhelm-4]

Werner,

If you look at the new KPA100 schematic and parts list (download the new
manual), you will see that C31 has a value of 0.22 uF.  The KPA100UPKT
instructions tell you to change the value on the schematic, but there is
no new C31 included with the kit.

In fact, I was directly involved with testing the newer T/R switch
design for the KPA100 as a Field Tester and afterward I discovered the
C31 problem.  Some KPA100s will oscillate at 600 to 800 kHz with the old
value C31 installed.  I had one of the first updated KPA100 that had
those symptoms on my workbench and found that C31 was not acting as an
effective bypass, so the updated value was included for all new
KPA100s.  It has not made it into the KPA100UPKT yet, but it should be soon.
Not all KPA100s show this problem, but many do, so it is best to change
C31 while you are adding the KPA100UPKT.

If you do not want to wait for the part from Elecraft, you can use most
any 0.22 uF cap rated at 50 volts or more - even 2 0.1 uf caps in
parallel (one on top of the board, the other on the bottom) will work
just fine too.

73,
Don W3FPR

Dr. Werner Furlan wrote:
> Where did you get this information? In my KPA 100 Kit C31 was 0.033 µV
> and in the latest manual and in the upgrade kit diagram it is also a 0.033 µV  
> (33N).
>
>
>  
_______________________________________________
Elecraft mailing list
Post to: [hidden email]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
 http://mailman.qth.net/mailman/listinfo/elecraft   

Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com