I have a working Marantz RFX77 RF extender for the TSU3000, TSU6000 and TSU7000 series for sale. This is the same as the Philips RFX6000.
[Link: ebay.com]I also have a bricked RFX9600 for sale. The power light comes on but the red busy led just flashes. It failed after a firmware update.
[Link: ebay.com]