It's all about the Software

Hello Simon,
I would like to ask you if there is the possibility to add another type of converter in sdrconsole, in the CONVERTER DEFINITIONS menu.
Currently available converters are working subtracting the local oscillator value from the desired frequency. F - OL
For some LNBs operating in C band it would be useful to have a calculation made in this way: OL - F
Typical OL value of these LNBs is 5150 MHz.
An example for frequency of 3623MHz would be:
5150-3623=1527 Mhz (IF), displaying 3623 MHz.
At the moment no SDR software, that I know, offers this possibility.
It would be great to have it in SDRCONSOLE.
Thanks in advance if you would like to consider this request.

73 Rocco IK8XLD

Try making the converter offset negative.

{^_^}

I have already tried, but unfortunately the negative sign in front of the OL value is not accepted and in any case it would not give the desired value.
Have you tried and had a positive outcome?
If so, please tell me how you did it.

73 Rocco IK8XLD

Simon can "salvage" current conventions moderately easily. Currently offset appears to be added to tuned frequency to give the input frequency and no I/Q swap is needed. If the offset is negative and adding that to the tuned frequency is a positive number then that is the input frequency with no I/Q swap required. (That's low side mixing.) If the offset is negative and adding that to the tuned frequency is negative then the tuned frequency is the absolute value of the result and an I/Q swap is required. (That's high side mixing.)

{^_^}

ik8xld wrote: Mon Oct 26, 2020 6:11 pm I have already tried, but unfortunately the negative sign in front of the OL value is not accepted and in any case it would not give the desired value.
Have you tried and had a positive outcome?
If so, please tell me how you did it.

73 Rocco IK8XLD

Switch between up- and down-converter.

I have just done some tests again and no available configuration is returning the correct result.
Also switching between up and down converter.
Being able to set a negative offset would help a lot.
Available for other suggested tests.

73 Rocco IK8XLD

A selection in the converter definition window would give maximum flexibility.

I'm sorry - I have not had time to understand this yet.

This really is a quite complex scenario which will have to wait, many other features ahead of this.

jdow wrote: Mon Oct 26, 2020 5:43 pm Try making the converter offset negative.

{^_^}

Hi Simon,
thanks for putting this implementation on your to-do list.
If you want to test the simple solution proposed by Jdow just enable this field to accept even negative values.
Available for any test.

73 Rocco IK8XLD

Hi Simon,
it is possible to simply enable the negative value here too?
See image above
Available to make test in beta version.

73 Rocco IK8XLD