Turing a 25" tv into an arcade monitor

P

PacManFan

Guest
Hello everyone,
I'm trying to turn a 25" TV into an arcade monitor. The TV has only an
RF input on the back, So what I'm tring to do is feed the RGB signal
directly to the RGB guns on the neckboard. I'm feeding the composite
sync through the RF input (Modulated to channel 3 through an RF
modulator). I set the TV to channel 3, and I've got a VERY bright and
washed out picture of my video game playing on the tv. The RGB signal
I'm feeding in is in the range of 0..1v p-p.
I think if I build an RGB video amp with an adjustable gain and bias
offset I'll be good to go.
What range of voltages are used to drive the neck board RGB tubes?

Thanks in advance.
Steve H.
 
"PacManFan" <steveh@crosslink.net> wrote in message
news:c9ad4bde.0311050628.7c70d0fd@posting.google.com...
Hello everyone,
I'm trying to turn a 25" TV into an arcade monitor. The TV has only an
RF input on the back, So what I'm tring to do is feed the RGB signal
directly to the RGB guns on the neckboard. I'm feeding the composite
sync through the RF input (Modulated to channel 3 through an RF
modulator). I set the TV to channel 3, and I've got a VERY bright and
washed out picture of my video game playing on the tv. The RGB signal
I'm feeding in is in the range of 0..1v p-p.
I think if I build an RGB video amp with an adjustable gain and bias
offset I'll be good to go.
What range of voltages are used to drive the neck board RGB tubes?

Thanks in advance.
Steve H.
Click to expand...
Are you feeding the signal to the driver stage on the neck board, or are you
trying to go directly to the pins on the CRT? The transistors that control
the guns are current driven, you should trace the circuit further back and
tie in on the main chassis, make sure you run the TV off an isolation
transformer though, as most arcade monitors do. This is one situation where
a schematic will be very helpful.
 
Are you 100% sure this tv set does NOT use a HOT chassis?
Do you have the service manual and the engineering specifications to
provide proper isolation between the two devices?
Basically what you are trying to do is typically NOT SAFE, or easy to
do as the engineering specifications of signal levels throughout the
set are not always available.

David

steveh@crosslink.net (PacManFan) wrote in message news:<c9ad4bde.0311050628.7c70d0fd@posting.google.com>...
Hello everyone,
I'm trying to turn a 25" TV into an arcade monitor. The TV has only an
RF input on the back, So what I'm tring to do is feed the RGB signal
directly to the RGB guns on the neckboard. I'm feeding the composite
sync through the RF input (Modulated to channel 3 through an RF
modulator). I set the TV to channel 3, and I've got a VERY bright and
washed out picture of my video game playing on the tv. The RGB signal
I'm feeding in is in the range of 0..1v p-p.
I think if I build an RGB video amp with an adjustable gain and bias
offset I'll be good to go.
What range of voltages are used to drive the neck board RGB tubes?

Thanks in advance.
Steve H.
Click to expand...
 
You must log in or register to reply here.

Welcome to EDABoard.com

Sponsor

Back
Top