Video amp on RFM / Ducksan chassis
cal50
to get a little extra bang for the buck out of my monitor. I have a
Samsung tube and the picture was pretty decent before I started
working on it. After the cap kit I picked up a Video amp from
Ultimarc. The hook up is really simple IF you read the instructions. I
did not get any instructions but I figured it out and here is a simple
picture if anyone else is doing this mod.
http://i645.photobucket.com/albums/uu178/cal50/RFM/cuttrace.jpg
The Ducksan chassis sync must be separate (2 lines) thus you cut the
trace on the circuit board for this operation. From initial
observation picture looks much improved. I will have to play with the
adjustments but it looks better. I cut the factory cable off and ran
these to the amp itself.
Pics-
Emil
Great work....
Dont forget to bridge resistor R4, and tune the contrast, and brightness
again.
Even possible that it is still to bright, and you may adjust the pot on the
high voltage transformator,next tot the focus pot on the thing.....
use well insulated material, and keep one hand in your pockeT!
Emil
"cal50" <jbha...@oh.rr.com> schreef in bericht
news:22e8e584-4d0d-4663...@k20g2000vbp.googlegroups.com...
Emil
+++++++++++++++++++
Exuse for mine bad english.
Yesterday put the amp on mine ducksan.
Althoug mine monitor was just great, it got even better!
See more colours, and get the fine nice razor sharpe contrast!
Monitor has to have an 4 volt signal on the rgb, but vga card does 1,5
volt.
Therfore the image could be way better if the monitor gets itts 4volts.
The amp is doein this. read also the websie of the amp.
Was an bit itchie to get it work, but here;s mine wiring:
======================
To put it on short:
First cut the circle half moon trace on the pcb of the amp.
Ducsan needs 2 syncs, an can NOT be combined. so you will cut the trace on
the pcb. see instruction on the website of the amp.
Wiring:
(RGB wires are conical, the inner cabel must be used from RGB, and put the
other wire, on ground!!!
This means all the rgb grounds connect to ground)
Connector monitror pinout amp
pin 1 (white inner cable (same for 3,5) RED
pin 2,4,6 GND
pin 3 GRN
pin 5 BLUE
pin 7 white on unmarked pin
pin 8 Yellow SYNC
pin 9 black GND
amp needs 5 volt, if vga card hassent this, then take power of an 5volt
connector of the molex. see instructions on amp website!!! (99% not needed
for an rfm)
Then, the whole thing is way to much amplified....
Williems had buid in this lack of voltage, and tried , TRIED, to compensate
this, bij adding resistor R4 brightness pot meter.
Bridge this resistor, and you are done, and enjoy this much better image.
You have to adjust contrast an brightness again.......
Some times, bridge r4 doesent do the trick and you still get distorted
image, there is an other pot on the main pcb, wich controlls contrast. turn
this pot, 1/3 anti clockwise.
You even may alter the brighness at the highvoltage transformer, next to the
focus pot...
Be care full, there is a huge amount of voltage there!
Any questions, just emial me....
Can send pics..
Emil
cal50
> Dont forget to bridge resistor R4, and tune the contrast, and brightness
> again.
Is the resistor R4 your referring to on the remote adjustment board in
the front of the cab behind the translite?
Right now my display is very bright but not overpowering. Not sure if
mine needs bridged or not.
A picture would be great......
Emil
Will make pic today.
Emil
"cal50" <jbha...@oh.rr.com> schreef in bericht
news:abc61279-4485-4050...@r34g2000vba.googlegroups.com...
David Schulpius
Thanks Emil for this info. I got this PCB Video Amplifier last week
and just got around to installing it last night on my Pin 2000, Star
Wars Ep1. I thought it would be a fast and easy install but quickly
found that it would be more involved then I thought. It turns out I
have a Ducksan monitor and no 5 volt feed from the video card in the
Pin 2000 computer. Thank God you had this write up or I would have
been out of luck. The first thing I did was wire in the outside
grounding brad from the R G B wires into the PCB think they were the
proper feed. I had no idea there was another wire inside the center
white insulation. Of course after I completed the faulty wiring and
turned on the game I had no picture. That's when I went searching for
an answer and found you. Thanks! Your info saved the day. I put the
center wires of the R G B into the proper spots and wired the outside
brad to the ground position on the PCB. Once done all I had to do was
jumper R4 on the remote adjustment board behind the translight and
fine tune the contrast, focus and brightness. What a difference!! Wow.
The other issue I had was not having a +5v feed from the video card to
power the PCB through the monitor cable. I had to pull it from the
power supply inside the computer. Using a volt meter I found the
proper voltage on one of the unused plugs on the back of the power
supply and connected my +5v & ground there by running two wires from
that connector back down to the PCB. I had to solder the 5v to the
back of the PCB but thankfully how to do that was documented on
Ultimarc's web site: http://www.ultimarc.com/vidamp.html . I just
plugged the ground from I ran from the power supply into the ground
position on the PCB and screwed it down.
Thanks goodness for all who posted on this procedure! Without this
info I would have been looking at a blank screen for a long time.
Have fun, Dave