[Boatanchors] Swap Mechanical filter and Xtals for 455.6KC Xtal

Wed, 30 Oct 2002 21:39:48 -0500

Phil, have you considered taking the case off and grinding the 453.5 on
freq?

Carl

----- Original Message -----
From: "Philip Atchley" <[email protected]>
To: <[email protected]>
Sent: Wednesday, October 30, 2002 7:17 PM
Subject: [Boatanchors] Swap Mechanical filter and Xtals for 455.6KC Xtal

> Hello.
> I've run into a snag on building my Longwave CW receiver.  I have an IF
> bandwidth of under 400Hz and an audio bandwidth (800Hz) of 70 to 400 Hz.
My
> problem is the only BFO crystals I have are 456.5 & 453.5 kHz (designed
for
> use with a 2kHz mechanical filter).  I've tried padding them down with
> various inductors and capacitors but they refuse to "rubber" more than a
> couple hundred Hz before they quit oscillating.  Guess they were designed
to
> be stable at their operating frequency!  I even tried a 455KC Xtal but it
> "zero beat" my IF almost perfectly.  No 800 Hz "tone" there!
>
> I NEED a crystal whose center frequency is about 455.8 to 455.9kHz.  It
> would be BEST if it were in a HC-6/U or CR-45/U plugin  housing but at
this
> point I really don't care! I will solder it into the circuit or change
> sockets if need be.
>
> WHAT I WILL SWAP FOR IT: (3 items)
> 1. Kokusai Electric mechanical filter, -6dB at 2KC, -60dB at 60KC. On
small
> board WITH matching transformers.
> 2. 456.5KC Xtal with HC-6/U socket.
> 3. 453.5KC Xtal with HC-6/U socket.
> These Xtals are "mated" to the Mechanical filter as they came out of the
> same set.  Should make a nice SSB adapter (product detector) for a BA that
> doesn't "DO" SSB so well.
>
> I'd like to get this set "up and running" before the winter Longwave DX
> season runs out <G>.
>
> 73 de Phil  KO6BB
>
>
>
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