Upgrading my Portsdown 4 to become a PortsLang 4

Inspired by a post by G8GKQ about new features available in the latest Portdown software release I decided it was time to upgrade my Portsdown 4 to enable it to be used as a Langstone on Narrowband modes, saving an extra box when man portable. The main change is the SDR is changed from the LimeSDR to an Adalm Pluto SDR. Looking at the benefits of the change revealed the only feature I would lose would be the Lime spectrum view which is not available on the pluto

I did have a spare Adalm Pluto obtained secondhand from HRD. but it was still in its plastic case. First task was to house it in a metal box which was much easier the second time around. Fitting it inside the Portsdown necessitated moving the antennuator board 1cm towards the front panel, which took much longer. 

The Langstone mode requires a "USB mouse" tuning knob and a USB sound card which would require additional USB ports (the RPI4 only has 4). I dug out the old USB3 powered hub and refitted it. I also found a dual port USB extension cable that allowed two of the ports on the hub to be accessed on the Portsdown rear panel.

The USB soundcard required fitting two 3.5mm stereo sockets for mic and phones to the rear panel to allow external access for a boom headset/microphone. A phono soocket was also added for a footswitch input to put the Langstone on transmit. The audio connector for the RPI audio output was kept.  All these additions made the portsdown rear panel crowded!

One great feature is that the band data pins on the RPI GPIO can be accessed from both the Portsdown and Langstone software so the band decoder can drive the 8 port RF switch and external transverter interface from both

Internal View

Rear panel is now very crowded

The powered USB and the Langstone USB soundcard