FT-8x7 Rig Locking

[VK2JDS]

I bought a ProgRock to see what they're like. Of marginal use for HF only.  The 'locking' method is a reprogram the PLL to compensate for drift. By default this happens if the 27MHz reference is off by more than 5Hz (can be changed to 1Hz). When it does a correction there is a sudden jump in output frequency.

Thanks for the reply Iain.

Yeah not suitable when running digital modes on the higher bands then... I might need to try the Leo Bodnar design. The TCXO he has in that GPS unit stays stable using historical data if GPS is lost, then once signal is received again it seamlessly corrects itself. Seeing as though the XRef-FT's are hard to come by now it's probably my only option.

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Yes it is true the way it works is to make a change to the N division of the pll, which is a cunning way to do it, rather than varying the dc voltage to a multioven expensive sinewave ocxo.
You can use this technique on the high bands for digital modes, if you assist the stabilisation of the progrock by thermally insulating the existing circuit, or better still , replacing the existing 27MHz crystal with a ebay tcxo. 
For field day microwave use on the bands up to 76 GHz I built mine into a diecast box with plenty of foam packing and its been great.
Also I have used it on 23cm moonbounce JT65C locking a IC910h. Its the backup for the expensive 10 MHz GPS locked source and xref I usually use.
You get what you pay for.
73 Dave vk2jds