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A new 7800 project... nothing major...



PCBs are designed, created, and already shipped headed my way as are a few components for me to populate the boards. I will go into more details once I have my PCBs and have been able to test and check out if my idea works the way I've planned or not. In the meantime, here is a pic of the PCB. If you are familiar with the UAV layout and install process needed for the 7800, then this should be obvious on what it is.


While what you see here is rather large, in reality it is only about the size of the UAV board so roughly 24mm tall and about 33mm wide. Pretty small.



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1 hour ago, RickR said:

Soldering that 4050 surface mount would be a challenge for me.  You'll have to share any tips you have for something like that. 


It will be a challenge for me as well. I've soldered some fine pitch stuff before, but nothing like this as I believe they are only like .3mm width or something to that effect?

My plan, will be to lightly tin one of the legs in the corner. Line up the chip and tap my iron onto it to anchor that point down. If it bridges, it isn't that big a deal because the next step would be to apply liquid flux liberally to the pins and then essentially drag solder across the pins with the solder that is beaded onto the iron. From there, it would just be more flux applied and then some swipes with the iron from the chip outward across a few pins at a time. I did something similar when I did my DCDigital install on my Dreamcast and have done similar on UAV boards that arrived not quite working properly in the past.


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That sounds like a good plan. 

For myself, I use a magnifier, but I'm finding as I age, it really exacerbates the shaking of my hands.  I have gotten into the habit of explaining what I want done and letting my 20-something child do it for me :) 


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Well it seems to work. I did make one very tiny mistake in my trace layout where I forgot one of the traces for the chroma fix circuit. But it can easily be fixed in situ with just a tiny bit of solder. But this is what it looks like. A 7800 mount PCB that incorporates the chroma fix and audio mixing that I normally add as separate components to a 7800 install. Only here it is all together and designed so that the PCB and header connectors get soldered to the mount board first and then solder the mount board to the various resistors that the video and audio are tapped from. Additional header pins would also be installed on the top side wherein the UAV would sit onto those pins and then get soldered down permanently to the mount pcb. Once I get a better system in place for getting it all together and pre do the soldering for the SMD components, this should shave quite a bit of time labor wise off ITC installs with a more professional look in the process. While it might save some labor time, it isn't going to reduce the cost I charge to do this work since I have added extra parts into the mix with professional made PCBs now. Still I'm hopeful that this will bring that little bit of extra to ITC installs of the 7800 UAV.

Here is a short video of it in action...










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