Where to put the caps in a Genesis Model 2 to RGBs Cable

[aconbere]

Hi All, This is my first post but I've been reading posts here for many years. More recently I've been working to make my own RGB cables, going direct from various consoles to BNC connectors and skipping scart. I have a prototype genesis -> bnc cable working, but it's ugly as sin, hoping some experienced folks on this forum might be able to give me some ideas.

Here's my prototype: http://imgur.com/7YnQEEk

It works: http://imgur.com/rxKl8rn

But I really have NO idea what to do with all those capacitors. They obviously wont fit in the existing mini din 9 housing I have. Here are some ideas I've considered.

1. Snipping the cable a few inches back from the housing and putting caps in a little box and wire it up. (no idea where this magical box will come from)
2. Getting small ceramic caps so maybe they would all fit
3. Getting axial capacitors so it's a bit smaller
4. Getting cute with various adaptors to use in between cabling
5. Crying myself to sleep in a bed of my failed cables

Would love any help folks can offer.

[Zeromemory]

The cable looks great, so far I made only RGB scart cables so i didn't have any space problems.

I don't know if these are ok for you, but I would try to fit these into the mini din housing:

https://www.aliexpress.com/item/Free-Sh ... .16.qLsshn

I don't know if something like Kinder Egg suprise box would be a good idea to keep these capacitors in.

[RGB0b]

I wouldn't use tantalam caps for this.

A breakout box might be the only way. Either that or installing them in the Genesis itself.

[andy251203]

Creating direct BNC cables is always going to be a challenge where capacitors are required. This is probably your best bet:

http://www.mouser.com/ProductDetail/Vis ... CWOh4KM%3d

These are the absolute smallest axial 220uf 10v capacitors available on Mouser.

[aconbere]

I wouldn't use tantalam caps for this.

A breakout box might be the only way. Either that or installing them in the Genesis itself.

Yeah I have definitely considered the genesis rgb bypass as a potential "solution" to this problem.

(Assuming you are retrorgb of http://retrorgb.com/ it's not lost on me that I'm learning most of this stuff from your site, thanks!).

[RGB0b]

Yup, that's me. The only issue with leaving the components on the console end, is the 32x: If you plan on using it, you'll actually need to put the components in the 32x, not the Genesis. Then you'll loose SMS & Virtua Racing support. It's a giant pain.

[aconbere]

I bought a bunch of axial caps and heat shrink tubing. I think my plan now is to run some wire from the male din to outside of the housing. Then connect that to the axial cap and the cap to the nicer shielded cabling. Heat shrink the wires and cap together.

Then heat shrink all of the caps and wires to the housing :-/

Will report back results

[viletim]

Hi All, This is my first post but I've been reading posts here for many years. More recently I've been working to make my own RGB cables, going direct from various consoles to BNC connectors and skipping scart. I have a prototype genesis -> bnc cable working, but it's ugly as sin, hoping some experienced folks on this forum might be able to give me some ideas.

Here's my prototype: http://imgur.com/7YnQEEk

It works: http://imgur.com/rxKl8rn

But I really have NO idea what to do with all those capacitors. They obviously wont fit in the existing mini din 9 housing I have. Here are some ideas I've considered.

1. Snipping the cable a few inches back from the housing and putting caps in a little box and wire it up. (no idea where this magical box will come from)
2. Getting small ceramic caps so maybe they would all fit
3. Getting axial capacitors so it's a bit smaller
4. Getting cute with various adaptors to use in between cabling
5. Crying myself to sleep in a bed of my failed cables

Would love any help folks can offer.

You can place the capacitors anywhere you like inside the cable. In addition to the capacitor, you also need a 75 ohm resistor in series with each colour signal. This should be places in the console end of the cable for the best performance.

I wouldn't use tantalam caps for this.

A breakout box might be the only way. Either that or installing them in the Genesis itself.

It's perfectly fine to use tantalum caps for video coupling. I do so on all of my RGB mod boards to save space. For best results I recommend using caps rated for a maximum of 6 volts or greater, but 4 volt rated caps can work if it's all you have. The trouble with tantalums is the cheap ones from unreliable sources such as Ebay, Aliexpress, etc. can have very high and inconsistent ESR.

[aconbere]

You can place the capacitors anywhere you like inside the cable. In addition to the capacitor, you also need a 75 ohm resistor in series with each colour signal. This should be places in the console end of the cable for the best performance.

Yeah, my question is more... "what is a nice way to bundle all these caps into the cable in an attractive way".

It's perfectly fine to use tantalum caps for video coupling. I do so on all of my RGB mod boards to save space. For best results I recommend using caps rated for a maximum of 6 volts or greater, but 4 volt rated caps can work if it's all you have. The trouble with tantalums is the cheap ones from unreliable sources such as Ebay, Aliexpress, etc. can have very high and inconsistent ESR.

I read this as RetroRGB saying that using tantalum caps inline in the cable was a bad idea, but maybe you also disagree with that!

Thanks!

[aconbere]

I took a second swing at this today.

http://imgur.com/wxaAywd

I just ran a bit of hookup wire from the din to the outside of the the casing, then soldered axial caps onto the hookup wire, then attached the coaxial cable that ran to the BNC connectors to those.

This is how it ended up looking in the end.

http://imgur.com/ZqisNip

Still a little janky (wish I had some shrink tubing that shrunk more), but the big issue is that somehow in wrestling with it all I messed up the connection to Red and Blue. This one went a LOT better than the last so this feels doable if not a little frustrating :P

Thanks for everyone's help!

[aconbere]

Ugh, it was the joint between the coax and the capacitor. The coax is sheared off at the insulation. I haven't figured out how to join the rather fine and mechanically week coaxial conductor to anything in a way that feels strong. Is there a trick to joining that conductor to stuff without weakening the cable?

[aconbere]

Maybe I should be installing a ferrule on the coax as soldering to that?

[aconbere]

Supplies for the next revision arrive this week. Going with retrorgb's suggestion of a break out box. I'll update as I get closer to manufacturing.

[aconbere]

Small update: All my parts arrived yesterday so I took some time to put together an enclosure.

Inside: http://imgur.com/QG7zMWB
Top: http://imgur.com/hj0Itv2
Side: http://imgur.com/q6P2Afb

I've managed to fit all four of the BCN adapters and two RCA. Nothing needs to get done to the audio signals but this makes it a convenient all in one box for terminating all the connectors.

I imagine tonight I'll try wiring in the various caps for the Genesis

[viletim]

Small update: All my parts arrived yesterday so I took some time to put together an enclosure.

Inside: http://imgur.com/QG7zMWB
Top: http://imgur.com/hj0Itv2
Side: http://imgur.com/q6P2Afb

I've managed to fit all four of the BCN adapters and two RCA. Nothing needs to get done to the audio signals but this makes it a convenient all in one box for terminating all the connectors.

I imagine tonight I'll try wiring in the various caps for the Genesis

It looks very solid. Better than having components sticking out like your previous attempt.

[aconbere]

I ended up wiring in the caps and connecting everything up last night. I'm waiting on a BNC crimper to finish the din break out before I can fully test, but I'm pretty confident that it will work, just a question of how well.

http://imgur.com/a/6udcc

My two worries are 1. interference and 2. ground loops (since everything shares a ground from the din9 shield I'm not sure if this a real concern)

I have some protoboards arriving this week for another project and I think the next one I build will likely just wire all the components into a little board, which should speed up construction substantially, but this is pretty simple.

[aconbere]

I have something working!

Here's how I constructed the cable: http://imgur.com/C8jtvhW

Here's a picture of it hooked up from the genesis to "The box" and subsequently to a little 14" PVM. (see previous posts for pictures of how that works): http://imgur.com/eKiqfPz

I haven't dealt with the audio yet but I just have a couple of RCA connectors to wire in there and it shouldn't be much trouble. It will be interesting to see if I get any hum though.

And here is a picture of the output looking super sharp and clean: http://imgur.com/vNpAaSh

The only part of this that I'm really not in love with is grounding the cabling. In particular the shielding on the mini coax is extreme and trying to get that all wired up nicely was hard (you can see my janky attempt poking out of the bottom of the din housing in the picture of it going to the box, I'll be shrink wrapping that away tonight).

Ideas for future revisions:

* I didn't put a resistor on the sync line in my box, gotta add that in.
* Using a little board for the components in the box so it's just a little nicer to connect stuff up
* Try using some prefab cables now that no components are inline (make stuff a little cleaner)
* Try making some cheap din9 -> din9 cables and just running it straight to a female din9 in the box

In general I'm not 100% sure what's required to keep noise out of the signals, this current attempt seems overly cautious, seems like I could probably dial that back substantially and get similar results.

[aconbere]

Thought I would follow up on progress moving through other systems.

I made an SNES / N64 cable this weekend. Using the same strategy as with the Genesis cables, both of these systems need caps on their signal lines and a pull down resistor on the sync line, so perfect candidates for hooking up to my box.

Cable: https://i.imgur.com/DTO1ldH.jpg
Connected to an n64: https://i.imgur.com/UPiNQzm.jpg
Connected to an SNES: http://imgur.com/a/IRxYa

So far this is working very nicely. I think my last real question is wether or not I can put this inline on my extron switch and just route all the consoles that need inline components through it there.