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Author Topic: WWV/WWVH and courtesy Icom 756 Pro II review  (Read 341 times)

Offline Josh

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WWV/WWVH and courtesy Icom 756 Pro II review
« on: December 05, 2018, 0131 UTC »

Just got a 756 Pro 2, haven't had an hf tx in ages, and went thru a vco and master ref osc alignment courtesy of a dmm and WWV/WWVH, all surprisingly coming in on all WWV freqs at this time.  Cheap and fast ref osc alignment; tune to WWV at the highest freq receivable and let the rig warm up an hour or so, then adjust u/lsb for same beat note, or if your rig does cw/r where the bfo can be placed on either side of the carrier in cw mode, flip between cw and cw/r while adjusting the ref osc until the tones match, you're now within a fraction of a Hz.

This thing's now within a fraction of a Hz at 25MHz.

All the vcos were off a bit as usual for a rig this old, many new HAM rigs don't even have vcos, lucky dogs. The B pll vcos were wayyyy off, weird as my first Pro (an original not a Pro2 or 3) all the pll A vcos were off, some by a large measure while the vco b side was perfect, I suppose that indicates the previous owner of my original Pro never used dual watch or otherwise utilised the vco b pll stream so they didn't age much. Seems the previous owner of the Pro 2 used the B vcos mostly as they were a mess and I messed them up further as the service manual for the Pro2 has some errata involving the vco b cap locations as depicted in the manual, but I sussed em out.

Dual Watch (where pll A and pll B are in operation at the same time) is a split RF stream that provides for rx on two freqs, same mode and filter bw, as long as those two freqs are inside the front end passband selected. It also has a nifty fish finder aka rudimentary fft specan screen that can show you up to 200KHz of spectrum. This was pretty high tech for 2002. The dsp chip in the Pro series is the same as the one in the glorious JRC NRD545, but lacks the filter flexibility and the "monkey chatter" dsp glitch 545s are known for. We will see how it fares as a swbc and utility rx.
We do not encourage any radio operations contrary to regulations.