[TenTec] CW-N versus CW-R

Robert Mcgraw rmcgraw at blomand.net
Thu Aug 1 14:29:30 EDT 2013


Another approach for the CW tuning challenge, use any of the current
software applications that provides a waterfall display.  Just match the
sidetone frequency to the transmitting station.  Most likely you will be
within 10 Hz or less.  With a bit of practice you can resolve to +/- 1
Hz.  Plus you'll see that the other station may not be very "frequency
stable".



73
Bob, K4TAX




> The tone recognition problem is had by many.  To avoid tuning above or
> below
> the desired tone, I use an AOR TDM-370 DSP audio filter, in stereo mode,
> with a CF of 700 Hz and a band width of 100 Hz (200 Hz and 300 Hz are
> also
> choices). When I tune a signal to the same frequency  in both ears I'm
> centered (within 10-20 HZ) on the other operator regardless of offset
> frequency, or sideband.  Otherwise the tone comes in one ear (low freq.)
> and
> out the other (high freq.) limited in frequency range by the BW.
>
> On a slightly different topic, not being able to properly tune in a SSB
> (no
> carrier as reference) because the voice type and its frequency range of
> the
> other operator is unknown, leads many operators to tune too high or too
> low.
> I find the panadapter function in PowerSDR and my Flex-1500 operated as a
> sub-receiver of my OMNI-VII, lets me zero-beat both the station I'm
> working,
> SSB, CW, or Digital modes.
>
>
> 73 ES DX,
> Gary -- AB9M
>
> -----Original Message-----
> From: Don Rasmussen
> Sent: Thursday, August 01, 2013 11:41 AM
> To: tentec at contesting.com
> Subject: [TenTec] CW-N versus CW-R
>
> Thanks to all for the clarification on this subject.
>
> I see that it is true that CW-N versus CW-R would be equal if the station
> is
> perfectly tuned in, but this rarely happens in practice.
>
> My tone recognition is good enough not to bother with visual aids on the
> rig
> but not always perfect.
>
> I found this:
>
> http://www.kb6nu.com/cw-bass-ackwards/
>
>
>
> "If you have properly zero beat the signal of a station with which you
> are
> in contact, then the other station’s signal will sound the same in
> either
> mode. An interfering signal will, however, sound much differently, and,
> as
> shown, may be out of the passband altogether.
> If you don’t zero beat properly, though, being in different modes will
> affect the way that the other station hears you. Say, for example, that
> both
> you and the other station are in normal CW mode (LCW on the TenTec). The
> other station’s transmit frequency is set to 7030 kHz. Your sidetone
> frequency is set to 500 Hz (meaning that the BFO frequency is 500 Hz
> above
> the receive signal), but you set your transceiver to hear a 600 Hz tone.
> To
> hear that 600 Hz tone, you will have to set your transmit frequency to
> 7030.1 kHz.
> If you’re in UCW mode, or CW-R mode as Icom calls it, then the BFO
> frequency
> will be 500 Hz below the received signal, and to hear a 600 Hz tone,
> you’ll
> have to set your transmit frequency to 7029.9 kHz. In the first case, the
> other station will hear a 500 Hz tone when receiving your signal. In the
> second case, he’ll hear a 700 Hz tone.
> To minimize the frequency difference between the two stations, it’s a
> good
> idea to check the setting of your sidetone frequency and zero beat as
> closely as possible with the other station. I would also avoid shifting
> between CW modes while in contact with another station, or if you do
> change
> modes, don’t change your transmit frequency while in contact. Use the
> RIT
> control to change the frequency of the tone you hear."
> From: Don Rasmussen <wb8yq...>
> Sent: Wednesday, July 31, 2013 10:21 AM
> Subject: CW-N versus CW-R
>
>
>
> Thanks to those who helped me align my OMNI VI+ BFO trimmers and TCXO.
> Without a frequency counter I would have been SUNK even though I have
> been
> able to perform the operation on other rigs with just an external
> receiver.
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-- 
Disclosure:
I am a Tentec Ambassador and compensated according to the Tentec
Ambassador plan. I serve as a volunteer beta test person for the Omni
VII, Eagle and Argonaut VI products.   Otherwise, I hold no business or
employment interest with Tentec.



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