Content-Transfer-Encoding: 8bit
Date: Tue, 25 Apr 2000 22:08:25 +0200
Message-ID: <4.1.20000425210402.0163b070@mailer.inrete.it>
Data: Tue, 25 Apr 2000 21:08:23 +0100
To: rsgb_lf_group@blacksheep.org
From: "M. Bruno" <spin@inrete.it>
Subject: RE: LF: Carrier on 137.7446
In-reply-to: <3617AC3245C2D1118A840000F805359C0175288F@pdw-mercury-1.der a.gov.uk>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii; format=flowed
Precedence: bulk
Reply-To: rsgb_lf_group@blacksheep.org
Sender: <majordom@post.thorcom.com>

In 15.04 25/04/00 , G4JNT wrote:

>On this subject, does anyone know of a low-cost source of 455 kHz
>(series resonance) crystals.  I want to make up a ladder filter for the
>RA1792 with a much narrower bandwidth than the 300 Hz mechanical filter
>included.  
It's hard, I tried to have 455 kHz xtals built on order, but the producer
says that he had no 'blanks' (raw slices of SiO2, I presume) available
for frequencies under 1 MHz - nobody wants them, today !

>Just a thought, but a ladder filter at 455 would be a lot easier.
>
My RA1792 has a 100 Hz xtal filter in place of the wire bridge on the
filter bank. This filter is rare, but sometime available.

73, Marco IK1ODO