Steve -
Gimmicks aren't too stable, but would be ok for experimentation. An NP0
trimmer might be ok.
I prefer a CW tone around 400-500 Hz as well. I also like to vary the tone a bit during a QSO,
which is why I never use transceive on CW. MUCH more convenient to be able to move the receiver
around a little to combat QRM, etc. without having the transmitter move as well. Hence the
'invention' of RIT!! CW transceive was marginally ok when everyone used LSB for CW, as 'most'
transmitters were then shifted in the same direction, by about the same amount. But these days CW
is accomplished in different ways, and may shift either way, purely as an attempt to 'match' the two
stations. Unfortunately this results in everybody having a different shift, AND some shifting in
the opposite (USB) direction. Separate control is MUCH better suited for CW.
73, Garey - K4OAH
Glen Allen, VA
Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line
and TR-4/C Service Supplement CDs
<www.k4oah.com>
Steve Wedge wrote:
Yup - shoulda looked at the schematic first. For some reason, I was thinking about that network
in the sidetone circuit. Though the sidetone is annoyingly high for me, it's how it was designed
and I'll leave it (I use a pitch of 440 Hz on rigs that have variable pitch). If I can even get
this to 800, I'd be okay with it. Looks like I need less capacitance than what's in there and the
value's small enough that I could use a gimmick, couldn't I?
Off to look for some 10 pf caps or a trimmer...
Steve Wedge, W1ES/4
Live free or die: Death is not the worst of evils.
John Stark.
All my computers have my signature with various pearls of wisdom appended
thereto.
--------------------------------------------------
From: "Garey Barrell" <[email protected]>
Sent: Thursday, April 05, 2012 10:22 PM
To: "Steve Wedge" <[email protected]>
Cc: "Drake List" <[email protected]>
Subject: Re: [Drakelist] Changing B-Line sidetone
Why not just replace C1 and correct the offset??
C1 needs to move the CO up about 800 Hz to put it within the passband of the LSB, anywhere from
about 800 to 2000 will work.
The frequency of the SIDETONE has nothing to do with the offset. It should be about 800 Hz, to
approximate the frequency offset in CW, but this frequency is set by the phase shift network at
V9a. This same tone is also used for the TUNE function so must be in the range of 350 - 2400 Hz.
73, Garey - K4OAH
Glen Allen, VA
Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line
and TR-4/C Service Supplement CDs
<www.k4oah.com>
Steve Wedge wrote:
I know this has been gone over before, but my B-Twins seem to be out of kilter: the usual
assumption is the offset is 800 Hz, but my set seems to be off by over a kHz (the offset seems
to be about 1.8 kHz). I know there are three r/c combos in the T-4X. Has anyone ever changed
these successfully?
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