“Mod for 10mhz reference” VK3HZ details:
Under certain conditions, some XRef-VS boards can generate a spurious output when the XRef is supposedly disabled (i.e. no 10 MHz applied).
The XRef-VS is mainly used for the TS-2000 and the IC-910H fitted with a hi-stab OEM oscillator.
The mod is applicable to XRef-VS boards delivered prior to the start of 2015. Later boards already have this modIfication. From the start of 2016, this mod is incorporated in the redesigned PCB.
** Note – This mod is NOT required and MUST NOT be done to an XRef-VT, XRef-FT or XRef-PLL board. **
You need a 10K 1/8W standard (i.e. not SMD) resistor – the smaller the better. You also need a short length of wire.
The mods are shown in red on the PCB overlays below. Note that these overlays show the full set of components used for both versions (VS and VT). The VS does not have anything where the large square outlines are shown (TCXO and adjustment trimpot, only on the VT).
