[Elecraft] New Crystals or Not

Mon Oct 28 19:31:00 2002

Some more clarification:  

Over the lifetime of the K2 we have made several incremental improvements to
our filter crystal matching. When we went to a tighter crystal motional
inductance (Lm) specification around 3/29/02, we first received crystals
sorted at the vendor with with the older 4.91-20 label, as opposed to the
4.91-0195 that we were using just previously. We then had them custom
labeled as 4.9136-S on subsequent shipments to us from the vendor.

Here is the breakdown of K2 filter crystal versions:

1)  4.91-20 used on early K2s

2)  4.91-0195 used on more recent K2s and SSB options sold -before-
approximately s/n 2570, 3/19/2002.

------

3)  4.91-20 (sorted to tighter Lm criteria at manufacturer) used from about
s/n 2570 (3/19/2002) and for a short time later until we received the
remarked crystals.

4)  4.9136-S (remarked and sorted for Lm at the manufacturer) used on K2s
after s/n 2570 after those in #3 above were used up. These are what we are
shipping for all K2s and KSB2s today.

------
The crystals used in #3 and #4 above are equivalent. The tighter Lm
specification results in slightly less filter loss in the CW filter and a
slightly wider bandwidth for the SSB filter. 

So if your K2 is in group #1 or #2, before s/n 2570 and it has the 4.91-0195
crystals in its CW or SSB filter or if it is a much earlier unit with the
4.91-20 crystals, you will probably see a small improvement from using the
newer crystals. They are available at: 
http://www.elecraft.com/order_form_parts.htm

Sorry for the confusion!

73,Eric  WA6HHQ
---------------------------------------------

-------- Original Message --------
Subject: Re: [Elecraft] New Crystals or Not
Date: Mon, 28 Oct 2002 14:38:52 -0800
From: Eric Swartz WA6HHQ - Elecraft <[email protected]>
Organization: Elecraft
To: [email protected]

As a follow on to my earlier email, we have been shipping the latest CW and
SSB filter crystals since about March 19th, 2002. Approximately from K2
serial number 2570 on.

-------- Original Message --------
Subject: Re: [Elecraft] New Crystals or Not
Date: Mon, 28 Oct 2002 11:54:10 -0800
From: Eric Swartz WA6HHQ - Elecraft <[email protected]>

All new K2s and SSB adapters are shipping with the latest filters crystals.
You can recognize them by their unique marking: ECS 4.9136-S.