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One more four the road

Nathan Strum


This is going to be a lot shorter than the last couple of projects. You can pick out details from those blog entries if you need to install a UAV mod of your own, but I'm not going to go over it all in detail again here - much of it is the same.


One last console to mod, and no repairs needed! This time - a four-switcher. Or as I like to call 'em, a four-banger:


Somehow, I don't think my console nicknames are catching on. 4x4? Foursider? No?


Anyway... here's its RF:


Pretty clean.


And the parts bound for it:

Yep - those are jacks! The plan this time was to drill holes in the case, and use jacks instead of pigtail cables. Also shown, from top left: a TBA internal audio board, a UAV mod, a Molex connector, and Console5 cap/refresh kit (lower left).


When I opened the case, it was absolutely pristine. This console had never been opened since it was manufactured - the screws hadn't been broken loose yet, and it still had the inspection tag taped in place:


The felt dust covers were still in like-new shape, as were the foil static strips (even though the adhesive had failed):

Consequently, John decided to not have me drill holes in the case, and go back to pigtail cables instead. Same functionality, no holes. Fewer angry purists. ;) 


But we still went ahead with the mod, because for the console to be useful to him, John needed it to have S-video and composite out. Here's where I found the connection points:

Apart from +5v, everything had to be soldered to the leg of something. A little tricky, but not bad if you take your time. Ground is just a via on the ground rail, and the RF shield doesn't cover it, so it's super-easy to access (soldered it from the underside).


And here's the mass of wires needed to connect it all:

I really miss the mostly plug-and-play installation of the CyberTech mod.


To get the wires out of the case, I used the RF-out hole. I modified it slightly, by filing about 1mm off one side:


While not strictly necessary, this allows me to fit the Molex connector through it, and allows the output cables to be completely removed later if needed:


The S-video and composite+audio cable fit quite easily. I used the same cables as the last two consoles I modded:


The trick now was... how to secure the mod boards? I really didn't want to stick the circuit boards down with double-stick tape. I think that's inelegant, and makes removal difficult. The advantage of the four-switch though, is there's a ton of room in the case, unlike the Jr. or even the 7800. So I decided to use... double-stick tape! But not to stick the mods down directly. Rather, I stuck some heavy 3M double-sided mounting tape to the back of some 2mm craft foam (leftover from the Jr. mod), making a couple of adhesive foam pads:


Then I stuck that down over a piece of solid wire (left over from some old cat5 cable):

The thick double-sided tape will keep the foam in place, and prevent the wire from tearing through it.


I added a second one for the TBA audio board:


Then I used the wire (along with a little heat-shrink tubing for cushioning) to anchor the boards down. This is similar to what I did with the Jr. Easily removable later, if needed.


The rest of the wiring is similar to what I did in the previous mods, including an inline Molex connector to allow easy disassembly later. The cables neatly fit into the stock RF cable guides. I cut a small notch into the RF shield (as I did with the Jr.) and covered the edges with electrical tape. RF is still intact and fully functional - but John would need to open the case up, and plug the cable back in:


Just needed to reinstall the static strips (with the addition of some new, thinner double-sided tape), foam dust covers, and... why not - the inspection tag, and it was ready to button back up:

Before I closed it up though, I wanted to check one more thing.


When I installed the TBA audio board in the Jr., it seemed loud. This time I did a comparison test, and it is LOUD. I output a test tone from the Color Bar cart, and dialed the monitor's volume down until my iPhone's decibel meter app stabilized at 85dB:


I then switched to RF - same console, same monitor, same volume setting and the level dropped nearly 10dB:

When running the TBA audio through a mixing circuit with my AtariVox, I had to turn the AtariVox's internal volume level all the way up to be heard against the volume of 2600. Note for anyone making audio mods: adjustable output would be nice. That, or just match the level of the RF modulator. But this audio mod wasn't designed for the 2600. It works with it, but it was designed for the Atari 8-bit computers first. Much like the UAV mod itself.


The picture (S-video shown here) is very clean. But it looks quite undersaturated to my eye. There's no adjustment for that, unfortunately. It is what it is:


Although in comparison to its RF from before the mod, it's pretty similar:



My sixer (with a CyberTech mod) is considerably more vibrant:

I suppose the only way to really judge the UAV would be to run a series of tests of it and other mods all on the same console. It would be nice if somebody did that. Eh... maybe I'll feel inspired someday. :roll: 

Anyway, it's all cleaned-up and buttoned-up and on its way to John, along with the 7800 and Jr. It seems to have not gotten much use - even the orange stripe around the bezel has almost no sign of wear on it. The cartridge slot contacts were a little dirty, but some of that can just be attributed to age. Even the toggle switches were pretty clean (I polished them up anyway with some Flitz).

So that wraps up all of John's consoles, and my series of UAV mod installs.


At some point, I'll mod my own 7800, and may fix up a couple more 2600s I have. But other than just maintaining my own console, I'm not really interested in taking on any more hardware projects right now.


Well... except for maybe one more thing. :ponder: 


Published 9:00 PM, 3/29/23

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That is a perfect location for that connector!  This is pretty hardcore what you're doing here.  :)



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1 hour ago, Albert said:

That is a perfect location for that connector!  This is pretty hardcore what you're doing here.  :)



I think you must've been looking at the draft before I added the captions. The Molex connector is actually internal - it doesn't stick out through the RF hole.

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1 minute ago, Nathan Strum said:

I think you must've been looking at the draft before I added the captions. The Molex connector is actually internal - it doesn't stick out through the RF hole.

Correct!  Now I will go look again.  :)



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@Albert has a lot of pics from his consoles that I did over the summer. Those attachment points are nearly the same ones I used. The difference is that I added a large section of shrink tubing around the UAV boards so I could use my industrial velcro to hold them down between the space of the select/reset switches and the RF modulator. I also get the +5 and Gnd from near that area as well. The ground can be had from an unused via near the RF output RCA jack on the board, and the +5 can be had from a ferrite bead just above the RF modulator area. 


The main issue I have with the UAV on 2600 systems is that some of the colors aren't being shown properly. Pitfall! is a prime example because the tree trunks will appear to be black vs the dark brown they actually are. So in essence some details could be lost in the games through the UAV output. However, it doesn't really seem that any of my clients have noticed this. As for the audio, what I was doing was to just add in another 10µf cap with the positive side attached next to one of the vias that the already in place 104 ceramic disc cap is using for audio and then run a wire from the negative lead to the RCAs. It is louder than the stock but still sounds good.


I've installed that Internal Audio board into a few systems and generally don't see a need for it over what I've already been doing with just some extra resistors or caps and it is easier to do that vs using that board since I have less to attach in the process. That said the use of one of the internal audio boards in a 400 I did a few months back was quite nice and is exactly what it was designed for. 


I could be wrong but I think the IAB is just a larger through hole version of Bryan's original UAC boards he sold for a brief while along with the UAVs years ago. The waveform from those older boards was reversed phased from how it should be and while most folks wouldn't have noticed this, I did and confirmed it when I compared the waveforms later. Not sure if the IABs also invert the audio or not.


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That size of heat shrink tubing sure didn't come in the Amazon discount box o' cut-offs I bought. ;) 


I used to use sticky-backed Velcro to secure things at work a lot, until I had to start removing it. The adhesive they use for that stuff is the absolute worst. It just turns into a gummy mess.


Of the three consoles I added a UAV to, the 7800 was by far the easiest because of the board you sent me (even though that console required the most repair to get working in the first place). I'd happily desolder and socket a TIA just to be able to plug in a CyberTech mod again, if those were still available.


I'd never used or seen a UAV before, and it kind-of became the go-to for these projects not because of any reported quality, but because it was readily available. As you mentioned, the darkest color values turned out too dark, with some being effectively indistinguishable from black. I'm hoping the CleanComp gets fully dialed in at some point, because I think that has the most promise of any 2600 mod I've seen in a long time.


Not sure I'd use this audio board again. I only discovered the complete lack of audio in the UAV after I had received them and began reading the instructions and wondered "Hey... where does the audio go?" :roll: So I saw it as a companion piece and figured it would probably be a vetted to work well with it. It's just okay. Couldn't tell you if the audio was inverted or not. The consoles are all on their way back to Champ Games World Headquarters now.

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Nice work Nathan 👏  


I really like the idea of a molex connector you have used and also hoping the ClearComp takes the next step as it's appears reasonably straight forward to install and use.

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