Re: #uBITX Firmware KD8CEC - IF-Shift etc. #ubitx

Allard PE1NWL
 

Jerry,

I believe it works in a similar way as the PBT (or "clarifier") function
in the Raduino v2 software for Bitx40.
https://github.com/amunters/bitx40-raduino-v2/blob/master/PBT.png
It allows the user to slightly shift the BFO frequency from the frontpanel
(only during RX of course).
It's not IF shift in its true sense, but the behaviour is quite similar.
I have the impression that not many BitX40 builders actually installed
this mod, which has always surprised me as I personally find it a very
useful feature.

73 Allard PE1NWL

On Sun, March 11, 2018 00:52, Jerry Gaffke via Groups.Io wrote:
OK, so IF-Shift is just a BFO offset (relative to the crystal filter
passband) 
that is for receive only, the transmit BFO offset generally stays put.
Makes sense.

I went off into the weeds there because Gerald's original query stated
that
 In LSB I can adjust the received sound with the IF-Shift with a
very pleasing effect, but this does not work the same with USB.
Sounded like there was something more going on.
But could be just that the code didn't quite handle the USB case
correctly.

Yes, eventually I'll move on to try some of the newer software.
But for now have my hands full with other projects.

Jerry  

On Sat, Mar 10, 2018 at 02:49 pm, Mike Woods wrote:


Most commercial rigs have an IF Shift or Passband Tuning (PBT)
control. 
This control can help with removal of QRM on receive ( e.g.by (
http://e.g.by ) eliminating a strong carrier or another station on the
edge
of the passband by shifting the passband up or down by a few 100 Hz. It
can also compensate for a poorly adjusted frequency response on a signal
that is being received (too bassy or too trebly). 
 
Ian’s software implements just such a control.  It functions in a
similar
manner to the BFO calibration routine, in fact, but unlike the
calibration
function, it should only operate on RX. This was the bug - it didn’t
turn
off on TX.  I checked on my uBITx and found the same problem here.
 
If you haven’t tried the KD8CEC firmware you should.  It has a number
of
other worthwhile software features!
 

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