----- Original Message -----
From: "Garey Barrell" <k4...@mindspring.com>
To: "Dave" <kaise...@yahoo.com>
Cc: <drakelist@zerobeat.net>
Sent: Thursday, December 02, 2010 2:54 PM
Subject: Re: [Drakelist] Improving Drake R-4B
Dave -
Not much needed. The AM filter is a bit of a problem, as
the 'B' has no optional filter capability. It 'MIGHT' be
possible to bypass the Passband Tuner and rely on the
'roofing' filter in the 1st IF which is a 6 kHz wide
half-lattice filter. The widest b/w for the Passband
Tuner is 4.8 kHz which is fine for picking off ONE
sideband of an AM signal.
There is a crystal chart in the manual, but all you need
to do is add 11.1 MHz to the frequency you want at the
bottom of a band. WWV and 30M would be 10.0 MHz plus 11.1
equals a 21.1 MHz crystal. International Crystal Mfg has
all the info, just tell them what frequency you want to
listen to.
73, Garey - K4OAH
Glen Allen, VA
My R4-B sounds OK on the short wave stations it will
hear (plenty on 40 meters). Because of the noise level on
most HF stations really wide bandwidth is not very
practical. There are a few very strong ones but mostly not.
BTW, its often possible to improve reception of stations
with severe selective fading by receiving it as an SSB
signal using the tunable IF to get rid of the original
carrier.
--
Richard Knoppow
Los Angeles
WB6KBL
dickb...@ix.netcom.com
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