My K3/10 has been used primarily with transverters for the VHF and higher bands (it has seen hardly any real use on the HF bands). A FCDPP connected via a splitter to the IF output of the 2m transverter, plus SDR-Console, provides a visual representation of VHF and above each band. I’ve never really worried about not having a display of activity on the lower bands.
Today I decided to try an SDR as a Panadapter using the IF output of the K3. This is clearly nothing new, there are many different setups described on the Internet. A quick online search did not find the same hardware as I’m using so this post may be of use to you, rather than just being a reminder for me at some point in the future. 🙂
The results so far have been excellent, I cannot believe that I’ve not tried this before! I can now see +/- 100kHz of the tuned frequency.
The K3 Interface Option (KXV3A) provides a buffered IF output which is at 8.213MHz. To receive at this frequency I used my NooElec combination of NESDR SMArt SDR dongle and Ham It UP Upconverter. More information can be found here. This is connected to the K3 IF output via a 10dB attenuator and short length of coaxial cable. On the software side, SDR-Console is my preferred software and Omnirig is used to sync the SDR and K3. General details on how to configure this in SDR-Console can be found here.
There are two areas where specific settings are needed for this hardware setup:
- As the NooElec upconverter is being used to enable the SDR to receive at 8.213MHz the IF frequency configuration in SDR-Console needs to be set to 133.213MHz (125MHz + IF frequency)
- The spectrum needs to be inverted. This caught me out at first. I was testing during the UK/IE Contest and the band was full of stations. It wasn’t immediately clear what was happening when I was tuning. To invert the spectrum you first need to enable the “invert spectrum” option and then check the box for the SDR you’re using.
I’ve only had the Panadapter working for a short time but it has already shown some ES activity on 10m which I doubt I would have come across by simply tuning across the band. I’ve had to add an offset of 2400Hz for the USB mode under the SDR Frequency Selection pane (shown previously) for the frequency to track correctly when changing from LSB to USB. Similar changes will need to be made for the other modes. I’m sure there are probably other minor software changes that can be made to make this Panadapter solution even better.