[TenTec] CW-N versus CW-R

[Bob McGraw - K4TAX]

The UCW and LCW modes for CW have effect on the way a CW signal is tuned. 
Tentec standardizes on the LSB mode although the Omni VII offers UCW and 
LCW.

For LCW as one tunes down in frequency the CW note decreases in frequency to 
zero.  In USB CW mode as one tunes up in frequency the CW note decreases in 
frequency to zero beat.  Thus it depends on which side of the transmitted 
carrier one approaches zero beat.  In both cases, UCW and LCW, zero beat is 
exactly the same frequency.  The firmware automatically adjusts the transmit 
frequency based on UCW or LCW plus the CW off-set or sidetone frequency. 
Therefore, if you choose a 700 Hz sidetone, when the received note is 700 Hz 
you are on the exact frequency of the transmitting station.

In CW there are no sidebands, just carrier.

73
Bob, K4TAX




----- Original Message ----- 
From: "GARY HUBER" <glhuber at msn.com>
To: "Don Rasmussen" <wb8yqj at yahoo.com>; "Discussion of Ten-Tec Equipment" 
<tentec at contesting.com>
Sent: Wednesday, July 31, 2013 7:48 PM
Subject: Re: [TenTec] CW-N versus CW-R


> UCW and LCW may be better labels, inferring the receive offset from zero 
> beat of the carrier. The same thing is happening with CW-N where LSB is 
> used 40 M and down and USB is used 20 M and up. It matters not what side 
> band others are using. If the radios have been frequency calibrated and TX 
> and RX are in sync, your 7005.250 kHz carriers (CW) should be on the same 
> frequency no matter if one is using a 500 Hz tone UCW (CW-R) and the other 
> is using 750 Hz LCW  (CW-N). We used to zero beat to no tone, then set the 
> BFO to the tone we liked.
>
> My Corsair-II has a spot button that when pushed, removes the BFO offset 
> so that you can tune to zero beat.  My OMNI-VII has an adjustable side 
> tone and carrier offset arrangement similar to the OMNI-VI+ but with the 
> option of using either UCW (USB) or LCW (LSB). I can monitor my OMNI-VII 
> with my FLEX-1500 in panadapter mode; thus far I have NOT seen any shift 
> in the OMNI-VII tx frequency when shifting between UCW and LCW.
>
> The important thing to remember is that the frequency/sideband shift 
> occurs in the receiving circuitry NOT on the transmitted frequency.
>
> 73 ES DX,
> Gary -- AB9M
>
> -----Original Message----- 
> From: Don Rasmussen
> Sent: Wednesday, July 31, 2013 12:21 PM
> To: tentec at contesting.com
> Subject: [TenTec] 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.
>
> While testing I noticed that OMNI VI+ is hearing the same CW signal at the 
> same frequency and tone as the FT2000 does when setup for CW receive on 
> lower sideband.
>
> Anyone know in general what "most" transceivers consider as the "Normal" 
> sideband to receive on CW?
>
> OMNI VI+ is fixed.
>
> When calling a station back from his CQ, assuming you always tune for a 
> 700hz received note, it seems that you would be coming back to the sender 
> on a slightly different frequency if receiving him on CW-LSB as compared 
> to CW-USB.
>
> Understand the transmitter always sends both sidebands. ;-)
>
> Any ideas?
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