Intellivision - worth the composite or S-Video mod?

[Uzumaki]

I've seen older posts that seems to suggest the basic AV mod is about the same or worse than original RF output. Has anything changed or is Intellivision still a hard beast to get clean video? Intellivision and NES are the only 2 game systems I have that doesn't have S-Video out presently and NES is a problem, either get a very hard to find $100+ PPU from Nintendo arcade (with a chance of glitchy color palette on some games) or suck it up with composite only option.

 

I have a choice of original Intellivision or Intellivision 3 which should be more or less the same. I has a Sears Arcade but it melted when my attempt to relocate power switch from secondary side to primary side went wrong Only the mainboard and 2 controllers survived.

[bradd1978]

I've seen the Composite mod done on the Intellivision and honestly its not worth it. The RF in my opinion looked just as good.

[shadow460]

Perhaps it might be worth it if you're looking to ditch the old TV and the new one lacks the F connector. I've had one or two systems with video mod, but I've never had the desire to mod one myself. I just make sure the RF and A/V connections from the system to the DVD player and, ultimately, the monitor are clean and tight.

[wileyc]

Remove the RF modulator and install Solarfox's composite modification with the 5V shunt circuit as described on the Intellivision subforum (the shunt is NOT optional).

 

The composite output will be very clean. The Intellivision wiki circuit produces a dirty signal, and the modulator introduces artifacting.

Edited October 30, 2013 by wileyc

[Charlie_]

The problem I have with my Intellivision RF is not quality. The RF display is probably one of the best I've seen.

However some TV's just don't like it. And the picture goes away. Like in Space Armada.

It has been a while but I think when I reach the level with yellow border on some of my TV's the picture goes away.... looses sync.

On other sets, it is fine. Maybe it does this on more modern TV's (LCD panels)

[retromod]

well I noticed exactly the same behaviour and it is due to power issues. It seems the yellow borders stresses the circuit and so leading to loose of syncronization. I've created my own mod for Intellivision and it works fine except some vertical lines and ghosting in "frog bog" due to the brighness.

Currently working on an improvement. The mod in the wiki doesn't work. I tried it several times - nothing on my tv. So I created my own one which worked just fine except the described issues. After I added a switch to the HF modulator (on the 9V line) most problems with vertical lines were gone - but the brighness issues remains on "frog bog". You may notice some "rolling" colors and red is some kind of bleeding and fading away on top of the screen. Seems the balance between the resistors and the rest of the circuit is not optimal.

 

I've also added real stereo/surround sound to the intellivision as done before on Coleco and Atari consoles and it sound really great. Now you have the feeling within the space spartians you are sitting in a cylon base star if you have the intellivoice modul connected.

check out the http://www.retrovideogamer.co.uk/ website for more information and available sound demos for all systems.

[retromod]

Modified my circuit yesterday. After adding a switch the brightness can now be controlled and it looks much better. But still the color bleeding exists between dark and highlighted areas. The interference also doesn't go away but it much better now. On Donkey Kong the building is now quite stable.

 

Only frog bag is still a problematic candidate. Due to all this highlighted regions and deep contrasts in playfield the mod can't compensate the bad input signal coming from mainboard. I will try to switch to 9 or 12 V with my mod may be it is more stable in critical conditions and has less interference within the power supply, lets see. I will also try to find a better video signal pin on the mainboard, does someone know one? (i have not studied the schematic yet nor got a picture with PCB compoenent location for an european model)

Another approach is to use a more sophisticated replacement for the BC549/2N3904. There are some candidates but this requires some ordering.

Edited January 10, 2014 by retromod

[ZarK]

Jmetal88 came up with a better solution to the Shunt circuit, with the use of a 78L05 or 7805.

 

Post with Solar Fox AV Mod:

http://atariage.com/forums/topic/222037-finally-got-an-intellivision/?p=2935605

 

And my original Shunt circuit with updated info at bottom:

https://atariage.com/forums/topic/212715-intellivision-2609-composite-video-and-rf-box-removal/

 

Basically, this should help eliminate most if not all ghosting and eliminate the RF module. Not sure yet if the wiki.intellivision.us or Solar Fox AV circuit produces a better picture.

Edited February 25, 2014 by ZarK

[yell0w_lantern]

After adding a switch the brightness can now be controlled and it looks much better.

 

What exactly did you do? I'm having trouble with my mod - way too dark.

I used JMetal's circuit.