[Elecraft] Blue trimmer capacitors - no more available

[Don Wilhelm]

All,

I would like to add that the non-availability of those 1-40pF trimmer 
capacitors impacts more Elecraft products than just the discontinued KFL1-4.
They were used as the nulling capacitors in all the Elecraft integrated 
wattmeters, so for that application, the KAT2, KAT1, KXAT1, KAT100, and 
KPA100 have been impacted.  The proper replacement for those wattmeter 
nulling capacitors is a 5-15pF trimmer E540012.
Also impacted are  the K2 trimmers used in the bandpass filters.  The 
5-15pF trimmers (E540012) work fine in the 10/12 meter bandpass filter, 
but do not have sufficient capacity for the 15/17 meter bandpass where a 
7-25pF trimmer (Elecraft PN 540011) is the substitute.
That fact requires a rewrite of the K2 manual stating that the red 
bodied trimmer capacitors are to be used at C32 and C34 while the white 
bodied trimmers are to be used at C44 and C46.  That information will be 
good until the manufacturer decides to change the capacitor body color 
to something different (which is a constant exposure when trying to 
identify parts by the body colors).

What I am saying is that the impact of the loss of these wide range 
temperature stable trimmers is not confined to the KFL1-4 board, but has 
a wide ranging impact not only for new Elecreaft kits, but for those 
wanting parts replacements.  One must communicate the use to 
parts at elecraft.com (and sales) to obtain the correct replacement trimmer 
capacitor.

The loss of that wide range trimmer capacitor is being felt in many 
areas of the K1, K2 and KX1 products.  The impact is greater than just 
the loss of the KFL1-4 option.

73,
Don W3FPR

---------------------------------------------------------------
Herbert and all,

There is no need for the KFL1 firmware to be open source, it is 
available from Elecraft as a spare part.  Elecraft will continue to 
support existing KFL1-4 boards with parts (except for replacement 
trimmer capacitors) for a good long time into the future.

In other words, even though the board has been discontinued, that does 
not mean support for that board has been retracted.
If I need to repair a KFL1-4 board that has a failed trimmer capacitor, 
I will then replace it with another temperature stable capacitor with 
lesser range an use whatever NP0 or C0G capacitors to restore it to 
working condition.

I have replaced a few of those blue bodied capacitors in the past, but 
the number has been very few considering the number of repairs I have 
done over the years.

73,
Don W3FPR

On 3/7/2015 5:49 PM, Humberto wrote:
> Hi,
>
> I think this is quite a good idea ! The talking arround it with the no
> longer available trimmers could be stopped by redesigning the filter
> with more fixed NP0 caps and less variable trimmers. A trimmer with
> 1 to 40pF is an evil an unneeded coponent.
>
> Give the firmware to "open source" and others may break their heads !
>
> 73, Herbert
> CT2IJD / DD0PC
>