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NEC TG-16/TE/TurboDuo => TG/PCE Repair/Mod Discussion => Topic started by: Greg2600 on February 10, 2012, 11:52:38 AM

Title: Converting to composite AV without modifying the case?
Post by: Greg2600 on February 10, 2012, 11:52:38 AM
Hi all, I recently got a US TG-16.  You may recognize my name from other forums like Atari Age or Digital Press.  Anyway, I've seen the simple looking modification instructions to convert a standard composite av cable to connect to pins on the expansion port.  So my question is, is it possible to do so with say small right-angle connectors, so that the wires would fit in there with the standard TG back case cover on?  I know with it on, it's right flush on the exp port.  If the answer is yes, would anyone be willing to make a cable for me?  I am simply useless when it comes to soldering.  I'd prefer a thin AV/RCA cable, maybe a 6 footer, because I would want to run it through that small opening on the cover that the AC adapter plug goes through. 
Title: Re: Converting to composite AV without modifying the case?
Post by: Game-Tech.US on February 10, 2012, 01:56:24 PM
I used to put the 3 rca jacks on the back of the case and route the cable through a notch in the rear cover, just like the ac adapter, easy. Pic (http://img109.imageshack.us/img109/7451/tg16rearavjacks.html).
Title: Re: Converting to composite AV without modifying the case?
Post by: ApolloBoy on February 11, 2012, 06:37:57 AM
The notch is a little small so you may have to file it out in order to get all the cables in. I modded someone's TG-16 in this way and probably the trickiest part is getting the jacks positioned in a way where they won't touch the motherboard.
Title: Re: Converting to composite AV without modifying the case?
Post by: Greg2600 on February 15, 2012, 02:42:09 PM
Well I'm not interested in doing anything with the motherboard.  I just want to plug into the audio and video out pins on the external port, and prefer to have it fit in place with the back cover still on.  Anyone know who would be interested making a cable for me?
Title: Re: Converting to composite AV without modifying the case?
Post by: HercTNT on February 15, 2012, 02:48:29 PM
Greg, so i understand correctly is this picture what your trying to do?
Title: Re: Converting to composite AV without modifying the case?
Post by: thesteve on February 15, 2012, 02:51:18 PM
how my encoders thread has anything to do with this i dont know

heres one i did
(http://www.pcenginefx.com/forums/index.php?action=dlattach;topic=10315.0;attach=789;image)
Title: Re: Converting to composite AV without modifying the case?
Post by: HercTNT on February 15, 2012, 03:00:49 PM
He does not want to modify the case though.
Title: Re: Converting to composite AV without modifying the case?
Post by: thesteve on February 15, 2012, 03:11:27 PM
i know, i wan mainly commenting on the link to my encoder thread by akaviolence
Title: Re: Converting to composite AV without modifying the case?
Post by: HercTNT on February 15, 2012, 03:36:11 PM
gotcha, nice job on that turbo.
Title: Re: Converting to composite AV without modifying the case?
Post by: Greg2600 on February 15, 2012, 03:36:45 PM
Greg, so i understand correctly is this picture what your trying to do?
Exactly that's it, as long as it would fit inside the cover.  I'd like something like that with like a 6 foot thin composite cable.  I say thin because I need it to fit through that small opening in the cover for the AC plug.  I've seen the instructions to alter a cable, but I am a disaster soldering.
Title: Re: Converting to composite AV without modifying the case?
Post by: thesteve on February 15, 2012, 03:42:26 PM
herc your connectors will fit
Title: Re: Converting to composite AV without modifying the case?
Post by: HercTNT on February 15, 2012, 03:46:40 PM
I could make such a cable, but I dont have the materials. that being said, you need to consider a few things. I'm pretty sure that a shielded cable is highly recommended. Also, Steve discovered that you really should have caps on those cables to prevent damaging feedback into the system.  Steve can correct me on this, i believe you need a 220uf cap on the video and 2 10uf caps on the audio. Give steve a pm and get his feedback on this. I cant speak for him but maybe he will throw you together a set. He is very reasonable.

edit: yea thats right, i still got three of them.
Title: Re: Converting to composite AV without modifying the case?
Post by: Greg2600 on February 15, 2012, 04:37:30 PM
so you do have them, or no?
Title: Re: Converting to composite AV without modifying the case?
Post by: HercTNT on February 15, 2012, 04:41:33 PM
I dont have everything that you would need. I have a connector that would attach well to the back of your turbo. I would still need the correct wire, caps, and rca jacks. If you bought the

parts i would make the cable. I'm awaiting word back from steve on what wire would work best. The wire has to hold your video as well as audio and might be a really tight fit if it would fit at

all.
Title: Re: Converting to composite AV without modifying the case?
Post by: thesteve on February 15, 2012, 04:51:25 PM
for short cables shielding is not an issue.
longer runs it is
yes on the caps+ to the system  - to the plugs
Title: Re: Converting to composite AV without modifying the case?
Post by: HercTNT on February 15, 2012, 04:56:31 PM
Steve, i have 470uf 16v and 10uf 16v. can the 470's be used in place of the 220's? if so all i would need is the wire and rca jacks.

EDIT:  NVM i found a set of 220's.

btw, was that yes to the ceramic cap between the composite and ground?
Title: Re: Converting to composite AV without modifying the case?
Post by: thesteve on February 15, 2012, 04:59:35 PM
yes
Title: Re: Converting to composite AV without modifying the case?
Post by: Game-Tech.US on February 17, 2012, 03:18:36 AM
how my encoders thread has anything to do with this i dont know
HA! Copy n paste failed me, link to pic of a tg16 I modded now fixed.
Title: Re: Converting to composite AV without modifying the case?
Post by: CGQuarterly on February 18, 2012, 03:56:36 PM
Just do this.

http://www.cgquarterly.com/articles/tg16_cable.htm

Chris
Title: Re: Converting to composite AV without modifying the case?
Post by: HercTNT on February 18, 2012, 05:27:00 PM
that is a hell of a find, nice work. However, it still should have the caps installed to protect the system from feedback. I dont think those caps would fit through the hole in the dust cover. Its the way he wants to route the wires thats holding this up. It does give me a crazy idea though. I wonder if tantalum caps could be soldered in-line with the wires. They would be small enough to fit through the dust cover hole, if you fed one wire at a time.
Title: Re: Converting to composite AV without modifying the case?
Post by: Bonknuts on February 18, 2012, 11:26:11 PM
Just make sure the video cable (your yellow plug) is a 75ohm impedance cable/wire. Video cable/write is transmitting high frequencies and the frequencies will reflect back into the signal via the wire (this is why there's a 75ohm load at termination to match the transmission cable's impedance). If you don't, you can get ghosting/ringing and other artifacts.
Title: Re: Converting to composite AV without modifying the case?
Post by: Keith Courage on February 19, 2012, 02:51:49 PM
I have never seen any artifacts or any other video issues when not using a capacitor. You should be fine without one.
Title: Re: Converting to composite AV without modifying the case?
Post by: HercTNT on February 19, 2012, 03:32:07 PM
its not video artifacts we are talking about. the caps are not to filter, they are to stop electrical feedback through the lines from damaging the system.
Title: Re: Converting to composite AV without modifying the case?
Post by: Greg2600 on February 25, 2012, 08:41:44 AM
can't the caps be further up the wire from the connection point, and remain within the back cover?

by the way, I've been snooping around ebay for one of those tennokoe 2 banks.  currently nothing in the states, just some beat up ones in France. 

Hong Kong game doctor has one already modded for $30, not sure to trust them.
Title: Re: Converting to composite AV without modifying the case?
Post by: HercTNT on February 25, 2012, 11:34:10 AM
kinda pricey on this one if you can't wait

http://www.gamebaz.com/?a=i&i=30323U