K4600 video processor w/ NTSC

I purchased and put together a K4600 video processor unit in the hopes of getting it to work w/ NTSC signals by making some changes. I had done some preliminary investigation before purchasing after finding the schematic and it seemed I could find drop in replacements for the PAL specific chips. I found a pin compatible NTSC decoder chip, the TDA4685 chip can be put in NTSC mode via I2C (not sure how I’m going to do that yet), but the TDA3505 which does most of the heavy lifting doesn’t seem to have a NTSC drop in, at first I thought the TDA4555 would work, but it is not the same pin count. The closest I’ve found is the TDA4580, but it doesn’t have the adjustment features (from what I can tell), and that is the most important part for me.

My question is, should even bother attempting this, or is there a similar product/project that will do the same as the K4600, but for NTSC signals. I just want a device that takes NTSC in, I can adjust the colors, etc, and puts out NTSC. Anything else is gravy…

Any ideas, etc greatly appreciated!
~brian

Sorry, this kit has been designed in 1995 and it has been obsolete since 2007.
We are not aware of any drop-in NTSC parts and we do not have a similar device for NTSC.
Why not look for an NTSC to PAL converter and use the kit as-is?

[quote=“VEL417”]Sorry, this kit has been designed in 1995 and it has been obsolete since 2007.
We are not aware of any drop-in NTSC parts and we do not have a similar device for NTSC.
Why not look for an NTSC to PAL converter and use the kit as-is?[/quote]

Good idea, that is what I ended up doing…

However, my circuit is not totally working. I’ve been tracing the signal from the input and I don’t seem to be getting any R/G/B out of the TDA3505 and I’ve verified the inputs (to the best I can). I’ve taken sshots with my scope in the event they may be useful.

Additionally, my kit did not come w/ SW4 so looking at the schematic it seemed to use the internal R/G/B I soldered one set to the common point.

In general, how does support go for these kits?

thanks for your help!
~brian

The switch is an option, it is not included in the kit.
Manual calls for wire jumpers instead.

If I remember well, the kit requires 15VDC to operate correctly. Colour will not be OK when 12VDC is used.

Since this is a very complex kit, it is almost impossible to troubleshoot from a distance.
We can still service it, if you return it.
We assume you are a US resident? Please call (817) 284 77 85 for RMA#
If not, please return kit for inspection/repair to:

Velleman Projects Tech. dept.
Legen Heirweg 33
9890 Gavere
Belgium

[quote=“VEL417”]The switch is an option, it is not included in the kit.
Manual calls for wire jumpers instead.

If I remember well, the kit requires 15VDC to operate correctly. Colour will not be OK when 12VDC is used.

Since this is a very complex kit, it is almost impossible to troubleshoot from a distance.
We can still service it, if you return it.
We assume you are a US resident? Please call (817) 284 77 85 for RMA#
If not, please return kit for inspection/repair to:

Velleman Projects Tech. dept.
Legen Heirweg 33
9890 Gavere
Belgium[/quote]

Hi, I am using a 16VDC power supply as recommended by someone from velleman. I also did use jumpers where the switch should be, but I didn’t see that in the manual, I will look again.

What is the cost for repair? Also, is there a pad/solder side image of the board available? I’d at least like to make sure I haven’t any shorts due to my soldering. I touched up my soldering and now I get no picture whereas before I had a picture, but it looked like vertical sync was off (and I saw there was no sync coming in via T3).

thanks,
~brian