XRef - 10MHz-Locked Reference Oscillator

Transceiver mods, fixes, issues, reviews

Re: XRef - 10MHz-Locked Reference Oscillator

Postby VK3HZ » Mon Apr 25, 2016 8:52 am

Hi Kevin,

There was an issue with some of the earlier boards where, under certain conditions, the divider chip could "take off" when the synthesizer was disabled (i.e. running the rig without 10 MHz connected). This then interfered with the standard Kenwood reference oscillator causing some strange effects.

There's a simple fix which was applied to later boards, then incorporated in a recent redesign of the PCB. I'll describe the mod in the next posting.

If you don't want to try the mod yourself, return the board to me and I'm happy to do it.

Regards,
Dave
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Re: XRef - 10MHz-Locked Reference Oscillator

Postby VK3HZ » Mon Apr 25, 2016 9:32 am

XRef-VS Modification

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).

Xref VS top mod.jpg
Top of PCB
Xref VS bottom mod.jpg
Underside of PCB

Begin by removing the SMD resistor that is crossed out in red on the top side of the PCB.
Solder the 10K 1/8W resistor to the top side of the PCB as shown.
Add the wire link on the underside of the PCB as shown.

That's it. Reinstall the board and enjoy trouble-free operation (now).

Regards,
Dave
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