SITREP
Where IKARA is at right now — what is running, what is not, and what is planned next.
IKARA is working well. The immediate development priority is reducing, or managing, the QRM generated by the MPPT solar charge controller.
Current state
The station is working well, and the equipment enclosure has performed extremely well. There was initially some uncertainty about how effectively it would resist water ingress. It has now been deployed for several weeks and has been through a variety of weather conditions without any apparent problems.
On power, the battery is a 300 Ah LiFePO₄ pack — significantly over-specified for the station’s normal requirements — and the connected solar panels provide approximately 675 watts of generating capacity.
Live power, environment and weather telemetry is published on the Kiosk page for anyone who wants to watch the station work.
Known issues Open
The main outstanding issue is electrical noise — interference, QRM — generated by the Victron MPPT solar charge controller. The controller is housed inside the same enclosure as the radio equipment and sits physically very close to it. Despite being a high-quality, high-performance controller, it still produces a significant amount of radio-frequency noise.
As at 9 September 2026, not enough work has yet been undertaken to properly reduce this interference.
How it is being managed now
Because the battery is well over-specified and there is around 675 W of solar available, it is entirely practical to switch the solar charging system off temporarily whenever the radio equipment is being used.
The array is deliberately generous for the load. The point is not to harvest more energy over a day — it is that the battery can be brought back to full quickly, and that in turn means the MPPT can stay switched off for longer while the radio is in use.
A useful analogy is a water tank supplied by a wind-powered pump. When the tank is full, there is no need to keep pumping. The pump can be stopped while water continues to be drawn from the tank, knowing there is still plenty of water in the well and plenty of wind to refill the tank when required.
IKARA’s battery and solar system work the same way: charging can be suspended during radio operations without creating an immediate power concern.
IKARA has a dedicated QRM Eliminator page for exactly this. It lets trusted users disconnect the MPPT charger remotely for a selected period. The system only permits this when operating conditions are suitable — when the battery holds sufficient stored energy and its voltage remains at an acceptable level. It is a practical way to get a quieter radio environment while the longer-term work is completed.
Planned work
Reducing the MPPT interference at source, rather than working around it:
- Improve the grounding of the MPPT controller.
- Install appropriate ferrites on the power cables entering and leaving the controller.
- Construct a shielded enclosure for the MPPT controller, and ensure the shielding is properly grounded.