Icom 706mkiig extended tx mod

Hello everyone,
Has anyone done the mod on the mk2g ?
I've watched many videos on the removal of the smd, but my radio looks different by having two smd's.
Do I remove them both or just the one on the right ?
Many thanks.  
Rusty CT500

Hi Iain,

All fun stuff this 'modding' malarkey isn't it?


The number of diodes present depends on the country or radio region the unit was destined for, yours looks like a UK version.

Remove both and the radio should become fully open.   


Don't believe me? (Why would you trust some old git on a forum eh?)


You could trawl through the circuit diagram on the service manual :-

https://www.repeater-builder.com/icom/pdfs/ic-706mk2-svc-man.pdf

(Best of luck with that one)


Scour the web further :-

https://baltic-labor.de/2022/03/ic-706-mkii-frequenzerweiterung/

(This is the mod in German but for a US market rig)


Be confused even more :-

https://www.qsl.net/z33t/ic-706mkiig_tx_mod_eng.html

(He left a diode in place)


Remove them all in a Japanese version and you still won't get access to all the CB frequencies.


Still doubt me? Then remove the one on the left of your image, try it and then remove the other after you've found out it isn't fully opened.

As per usual the typical warnings apply.....DO THIS MODIFICATION AT YOUR OWN RISK!

If you fluff it up by stuffing in your grandfathers old plumbing soldering iron, or damage the printed circuit board trying to get some wire cutters in there then that's on you and nobody else.

Someone's bound to come along and place a "seed-of-doubt" but that's the way of forums nowadays...."He ain't even got one on his equipment list!" 


Best of luck. Oh, and all the best,

Victor

Thanks for your brief reply , and advice.
I've not done this type of surgery for a long time, so waiting for a new pointy soldering iron to arrive. Meantime I'll look at your links. You're correct, mine is UK version bought in Haydons many years ago .... If it fails, my Alinco dx10 will arrive in next week or so 🤩 Thanks again Victor, much appreciated, and I wish you a good weekend. Rusty

I'm known to 'waffle' Rusty.
(But I like to do my best to help out where I can. )

Proper 'pointy' soldering iron should do the job.



Have a great weekend and again, best of luck with it all!

A couple of nice dollops of flux such as Amtech 559 will make the job easier. Just make sure to clean the residue off after desoldering. This advice comes from someone who is terrified of components smaller than a 20W wire wound resistor.

Thank you for advice. Going to try the mod this weekend, hopefully.

I’ve never found flux helpful for removing components - for 2 pad (and more) devices the problem is getting all the pins/pads hot at once
And Then, removing the device without lifting any tracks (particularly important if the component might/will be replaced later )

For very small devices adding a little new solder to one end and leaving the iron there will also soften the other end enough that you can slide or flip off the component. It may come loose/off on the iron but otherwise slide is preferred as less likely to spread solder or lift pads. If extra side pressure is needed a cocktail stick won’t damage the board as it slips ! (Unlike the iron)

If you’re unsure give yourself a 1day training course with any old router etc that has SMD components. Sit yourself down and remove the components until you can do it quickly and cleanly every time.

For components with 4 or more pins a desoldering heat gun is pretty essential and it will take you a lot of tries to learn to get them off cleanly.

For fitting new parts or cleaning up pads (why?) a small amount of no-clean rework flux in addition to flux cored solder wire is often needed. Excess flux just leads to excess cleanup !

Thanks. Not done soldering for many years now, so I'm as you suggest, I'm practicing on an old Humax box. Got some servisol to help with clean up too . Best wishes, thanks.

Blimey more screwdriver mods then I can handle leave it to the experts. It is frustrating when I see the word on eBay screwdriver on some posts on the radio section I steer well clear of stuff when the seller says no returns due to screwdriver experts etc .we all claim to be soldering experts or something of that nature leave it to those in the know .