Date: Mon, 4 Oct 1999 05:36:46 -0400
From: "Bernd Neubig" <BNeubig@compuserve.com>
Subject: Re: LF: Receivers
To: rsgb_lf_group@blacksheep.org
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de DK1AG:

I am evaluationg, if I am to design a front-end crystal filter with a
bandwidth just equal to the width of the 136 kHz LF band.
It will be a four-pole filter with an ultimate attenuation of 60 dB and a
shpae facttor of 60dB to 6dB of approximately 4 (four).
For good match at the antenna side, probably an input attenuator should be
added inf ront of it.
Attention: There is a maximum input power of 10mW allowed, this means it
must be avoided, that it is connected at any time
with the transmitter ourput.

As this needs some design efforts, and there are some cost related to it, I
want to ask the lowfer-community,
- What do you think about the idea?
- Who would be interested to purchase such a filter (expected price in the
200.-DM range)?
- What is the bestl termination impedance  ? Is 50 ohms fine or should it
be in the kilo-ohms range?
- Could it be in an enclosure with solder-pins or preferably with BNC or
UHF connectors?

Please let me know your answer either in this mail-box panel or directly to
my e-mail address
BNeubig@compuserve.com

Bernd
DK 1 AG


P.S.: I am with Tele Quarz in Neckarbischofsheim, Germany