Where to get a logic level c-sync signal on the PCE?

[keropi]

Hello!

is there a place to get c-sync at logic level from the PCE? I want to pass it through the amp discussed here so I can use it with RGB:



I have already tried with the expansion port point and pin #44 of Hu6260 but unfortunately none worked with the amp as is.
Anyone knows of another point to try?
TIA! 

[thesteve]

there is not
C-sync is at 300mV in the PCE at the chip
that circuit is for reducing 5V sync to 0.6V (600mV) sync

[keropi]

I see... so what would be the best way to make it usable? pass it through a 4 channel video amp like the 7374 (3 channels for RGB and the last one for c-sync) ?

[NightWolve]

I'm no expert, but what's wrong with that Japanese-designed amp here?



That transistor is about the same as the generic Radioshack 2n3904 according to steve (I asked him to compare it against the S8050 and he said they're about the same, so a very easy to build circuit there, even so, you can still find the 2C1815 for sale on eBay sometimes).

References:
http://www.gamesx.com/grafx/pce_rgb.jpg
http://console5.com/wiki/Hu6260 (there's a link here to buy a whole kit to build it)

Note: the RGB amps are exactly the same, 3 times over, but the one for C-Sync is slightly different, using a 300 Ohm resistor to the power input of the transistor instead of 10 Ohms.


EDIT: Well, out of curiosity I read through your link at assemblergames and see that you had already built an amplifier based on that Japanese design, and the issue is that you really wanna use that chip for a more superior one. So eh, nevermind then. Good luck though.

[thesteve]

RGB amp with logic level sync

[keropi]

@NightWolve:

yep, I was trying to use the 7314 to hopefully get superior results. I have now abandoned this quest after all this time, it was going nowhere unless someone could use an oscilloscope to measure the signals that the pce outputs. I was able to have nice results with the 7314 but they did not match the old transistor based one. Most notably the colors, the 7314 seemed to have washed out ones. I have laso tried another schematic from a gamesx forum thread but it had the same results.
So because I cannot measure the signals I just abandoned this and went back to the classic amp....

@thesteve

thanks , may come in use in the future