Yes your observations are correct Bob,
and I agree that it's important that the correct frequency is displayed
during TX.
I have already corrected this in the next version v1.14 which will be
released soon.
The display will show the correct frequency both in RX as well as in TX.
However it will still use TX offset, not RX offset (perhaps XIT would be a
better name).
73 Allard PE1NWL
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On Wed, May 31, 2017 22:44, Bob wrote:
I've been working with a friend of mine, Willy W1LY, and his BITX40.
??Willy had installed the version 1.13 software from Allard and the HW
modifications needed and was happily working CW. ??He very carefully
calibrated the radio and chose a 600 Hz CW offset. ??Even so he noticed a
problem on transmit. ??If he set the display of his BITX40 to 7.039.0 MHz,
he noticed that his signal was reported as 7.038.4 on the spotting
networks. ??It appeared that the CW Offset was being applied on transmit
rather than receive.
The reference point for amateur transmissions is the transmit carrier
frequency. ??That is what is entered into one's log. ??That's all the
regulatory agencies care about -- - what your transmit frequency is. ??You
would look at your display frequency and write that down. ??So if the
display says 7.039.0 MHz that is what you log and that should be the
transmit frequency.
However, in the case of 1.13 firmware, that is not the case. ??the
CW_OFFSET is applied at TX time. ??The following three lines of code show
that CWoffset is set to the CW_OFFSET (established at calibration time),
the frequency is then set to the display frequency plus that offset by
setFequency, and the PTT switch is activated.
?? ?? ?? CWoffset = CW_OFFSET;
?? ?? ?? setFrequency(frequency);
?? ?? ?? digitalWrite(TX_RX, 1); // activate the PTT switch - go in
transmit mode
??
When the transmission is completed (the timer expires), the code sets the
radio back into RX, then clears out CWoffset, and sets the frequency back
to the dial frequency (with no offset).
?? ?? digitalWrite(TX_RX, 0); // release the PTT??switch - go back to
receive mode
?? ?? CWoffset = 0;
?? ?? setFrequency(frequency);
??
This is actually the opposite of what should ideally be going on. ??As it
stands now, the TX Carrier frequency is not what the user is expecting,
and it means that spotting networks are off.
Maybe there is some reason like code size that the TX offset is used, but
to get the BITX40 on the same page with other radios, to have their
frequency display agree and their spots to be accurate, changing to RX
offset would be best.
73, Bob, WB4SON
Allard PE1NWL