WA2EHZ Icom IC-706Tuner Mod

I mentioned earlier that I need to find a better way of tuning this IC-706 with the ATU-100 tuner - going to FM just isn't gonna cut it. 

I'd done some research and found a variety of mods that connect to the tuner connector on the rear and convince the radio that a supported Icom tuner is connected, allowing the Tune button to work. 

There were a variety of home brew options, going from two components on a modified molex right up to premade versions of the same thing including timer ICs and other additional "bits".

I've had my eye on https://www.ebay.com.au/itm/10w-Ten-a-Tuner-Module-Icom-706-718-746-756-756-PRO-7000-7100-7200-7300-W2ENY/233354189825?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649 - this looks tidy, but it goes from being an AU$15 component to a $45 component once it's shipped.

I've decided to have a crack at the WA2EHZ solution I read about here

I'm an IT guy, so molex connectors are something I have plenty of. Just a minor bit of work to knock the corners off one side. I probably had a suitable 100K resistor as well, but they're cheap. A quick eBay order for the 470uF capacitor & the 100K resistor, and I'm out all fo $7.79. That's a lot less than $45. 

** Note for this bright spark that the positive end of the capacitor has the white box rather than black.  

For what it's worth, I found one site that had a similar diagram but they seem to have their wiring completely back to front, with the pointy side being the ground. I went off a general consensus of wiring diagrams - of which there are quite a few, that all indicated that Larry WA2EHZ has his wiring the correct way around.

I like the simplicity of this circuit. Less is more. The capacitor choice should tune for about 8 seconds. The ATU-100 generally doesn't take that long anyway, so I suspect I'll be manually stopping the tune on the radio.

If it works, then it's <$10 including whatever heatshrink I eventually buy to cover it, and that saving goes toward the next coax switch I need.

If it doesn't, well the $15 solution that was going to wind up costing $45 will have cost me $53.  Worth a shot.

I'd been a bit reluctant at first - this radio to me is new, and it's still got a pretty high market value given its popularity as a HF/VHF/UHF radio, and I'd hate to kill it. My budget is shot though, and I don't much care for waiting for anything from the US this time of year, so a DIY option suits me. 

It's hardly the riskiest mod that this radio will need. I'm considering the mod to keep the fan on. Pretty much as nearly every site says, they run pretty warm, and that's just doing RX. I'm not entirely sure I'm up for this one just yet, but it'll be in its future.