Re: Can't get my uBitX to transmit CW on the Dial frequency

Tim Gorman
 

Jerry,

On Fri, 15 Jun 2018 11:54:42 -0700
"Jerry Gaffke via Groups.Io" <jgaffke=yahoo.com@groups.io> wrote:

Tim,

I'm not convinced. you can't just move the BFO to receive CW.
That's not what is being discussed.


Assume you are receiving an upper sideband phone signal at your 7030
mhz. The crystal filter is only allowing through that upper sideband
energy between roughly 7030.500 khz and 7032.500 khz, any residual
carrier from the transmitter is further suppressed by our 12mhz
crystal filter.
We are talking about changing from CWL to CWU, not from SSB to CW.

Now, assume that remote transmitter switches to a CW transmission at
7030 khz. We are now only interested in the carrier at 7030 khz, but
the crystal filter is not allowing that carrier through.  Does not
matter where we place the bfo, there is simply no signal to hear.
(Assuming our filter is perfect).
The remote transmitter is already sending CW. There is no switching
involved.


The solution is to special case the reception of a CW signal.
When receiving in upper sideband mode, we should have the receiver
tuned for a frequency 700 hz lower than that displayed in the LCD.
And when receiving in upper sideband mode, we should have the
receiver tuned for a frequency 700 hz higher than that displayed in
the LCD. The BFO can stay where it was for SSB phone reception.
We aren't talking about using USB and LSB to receive CW, we are talking
about using the CW mode to receive CW. Since it is a carrier we can
receive either on the upper side of the carrier or on the lower side of
the carrier.

But there is no reason to have to tune to a different indicated
frequency for receive. Just adjust your vfo or your bfo and leave the
indicated receive frequency the same as the transmit frequency. I used
to ue the adjustable BFO in my old RME-4350 to move from one side of
the CW signal to the other to avoid interference.

tim ab0wr

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