Making a Camcorder Viewfinder Work

[Captain Blammo]

I've got a viewfinder from a broken old camcorder, and am trying to figure
the pinout for it. The camera itself actually works, so I can power it up
and measure things, but I have no oscilloscope.

There are 5 conductors, 2 of which are power. I'm pretty sure that one is
horizontal sync, because I get the classic pattern of ~30 degree sloped
lines moving slowly down the screen if I connect 2 conductors (I can't
recall which just now) to a standard NTSC signal. I also get a fleeting
distorted image for a couple of seconds before the pattern settles in.

What's the minimum equipment I'm likely to need to figure out what is coming
out of each conductor from the camera? Also, does anyone know what I'd need
to strip out the horizontal sync from an NTSC signal and put it on a
separate conductor? Something cheap, small and not power hungry would be
good, because I'm trying to use it as a poor man's head mounted display.

If it's any help, the viewfinder is from a very old Magnavox Easycam 8.

Ewan

 

[Richard]

"Captain Blammo" <eas6@nbnet.nb.ca> wrote in message news:<CxQpd.185948$Np3.7557013@ursa-nb00s0.nbnet.nb.ca>...

I've got a viewfinder from a broken old camcorder, and am trying to figure
the pinout for it. The camera itself actually works, so I can power it up
and measure things, but I have no oscilloscope.

There are 5 conductors, 2 of which are power. I'm pretty sure that one is
horizontal sync, because I get the classic pattern of ~30 degree sloped
lines moving slowly down the screen if I connect 2 conductors (I can't
recall which just now) to a standard NTSC signal. I also get a fleeting
distorted image for a couple of seconds before the pattern settles in.

Hmm, don't know muuch about Magnavox but my service manual for a Sony

CCD-TR78, 88, 98, 99, 514, 590, 614, 714 814 shows a 5 conductor flex
going to the viewfinder board VF-102 as 1- 5V, 2- GND, 3- Video, 4-
tally, 5- NC. a lot of these are very simular.
Hope that helps

Richard

 

[Captain Blammo]

Hmm, don't know muuch about Magnavox but my service manual for a Sony
CCD-TR78, 88, 98, 99, 514, 590, 614, 714 814 shows a 5 conductor flex
going to the viewfinder board VF-102 as 1- 5V, 2- GND, 3- Video, 4-
tally, 5- NC. a lot of these are very simular.

Funny you should mention it, I actually have a viewfinder from a Sony
CCD-TRV22 as well, but it only has the four conductors going into the VF-102
board (Nothing on pin 5). Do you happen to know if scraping the surface off
those cables is a good way to get at the conductors? I don't have the right
connector to plug the end of the cable into. Also, does your manual mention
what video format the viewfinder takes?

Secondarily, and please do pardon my ignorance here, I'm not well versed in
the art of pinout parlay. What does "tally" mean? I assume that "NC" means
"Not Connected".

Thanks for the info!

Ewan

 

[Richard]

Maybe I can play with it

more tomorrow.
Richard

OK Ewan played with it a little this morning. Applying a standard line
out video signal to Pin 3, OOhhh little tiny TV! but where's the
sound? So that works as I thought 'cause I'd played with these before.

Richard

 

[Rich Grise]

On Fri, 03 Dec 2004 06:59:38 -0800, Richard wrote:

Maybe I can play with it
more tomorrow.
Richard

OK Ewan played with it a little this morning. Applying a standard line out
video signal to Pin 3, OOhhh little tiny TV! but where's the sound? So
that works as I thought 'cause I'd played with these before.

I remember when my little brother was just barely able to sit up and watch

TV, we were all in the car and Dad turned on the radio. Little bro started
looking around at the windshield, dashboard, whatever, asking, "Where's
the picture?"

;-)
Rich

 

[Captain Blammo]

OK Ewan played with it a little this morning. Applying a standard line
out video signal to Pin 3, OOhhh little tiny TV! but where's the
sound? So that works as I thought 'cause I'd played with these before.

Aha, well, I now seem to have the complete set of info for making it work.
Thanks hugely, I'll try jamming some Cat5 wires in there and seeing if it
works.

By the way, shouldn't the other conductor from the video cable be connected
to something? Should I tie it to GND, perhaps? Either way, as long as it
works, I'm happy.

Cheers!

Ewan

 

[Richard]

Aha, well, I now seem to have the complete set of info for making it work.
Thanks hugely, I'll try jamming some Cat5 wires in there and seeing if it
works.

By the way, shouldn't the other conductor from the video cable be connected
to something? Should I tie it to GND, perhaps? Either way, as long as it
works, I'm happy.

Cheers!

Ewan

Ewan,
Hope this dosen't get posted twice. I posted last night but it hasn't
shown up 18 hrs later.
Yes that's right the ground is shared by everything. Use the solid
wire as a temp thing and scab another connector to make a permanent
connection.

Richard

 

[Rich Grise]

On Sat, 27 Nov 2004 01:14:10 +0000, Captain Blammo wrote:

I've got a viewfinder from a broken old camcorder, and am trying to figure
the pinout for it. The camera itself actually works, so I can power it up
and measure things, but I have no oscilloscope.

There are 5 conductors, 2 of which are power. I'm pretty sure that one is
horizontal sync, because I get the classic pattern of ~30 degree sloped
lines moving slowly down the screen if I connect 2 conductors (I can't
recall which just now) to a standard NTSC signal. I also get a fleeting
distorted image for a couple of seconds before the pattern settles in.

What's the minimum equipment I'm likely to need to figure out what is
coming out of each conductor from the camera? Also, does anyone know what
I'd need to strip out the horizontal sync from an NTSC signal and put it
on a separate conductor? Something cheap, small and not power hungry would
be good, because I'm trying to use it as a poor man's head mounted
display.

If it's any help, the viewfinder is from a very old Magnavox Easycam 8.

The minimum you'll need to figure out what is coming from each conductor
is a 'scope and meter.

I've just been perusing ebay, and it seems to be just thick with scopes.
Buy as much scope as you can afford, if you really intend to build stuff
like a PMHUD.

If you need advice on which to buy, please post any questions.

Good Luck!
Rich

 

[Richard]

"Captain Blammo" <eas6@nbnet.nb.ca> wrote in message news:<yxRrd.189695$Np3.7727341@ursa-nb00s0.nbnet.nb.ca>...

Hmm, don't know muuch about Magnavox but my service manual for a Sony
CCD-TR78, 88, 98, 99, 514, 590, 614, 714 814 shows a 5 conductor flex
going to the viewfinder board VF-102 as 1- 5V, 2- GND, 3- Video, 4-
tally, 5- NC. a lot of these are very simular.

Funny you should mention it, I actually have a viewfinder from a Sony
CCD-TRV22 as well, but it only has the four conductors going into the VF-102
board (Nothing on pin 5). Do you happen to know if scraping the surface off
those cables is a good way to get at the conductors? I don't have the right
connector to plug the end of the cable into. Also, does your manual mention
what video format the viewfinder takes?

Secondarily, and please do pardon my ignorance here, I'm not well versed in
the art of pinout parlay. What does "tally" mean? I assume that "NC" means
"Not Connected".

Thanks for the info!

Ewan

Hey Ewan,
Took a quick look at another Sony I have in pieces. It has a 4
conductor cable going to the viewfinder. It follows the same layout as
above and yes pin 5 is No Connection. In this case just not there. Pin
4 is Tally which actually is a video term for the little light that
comes on when the camera is recording. (In a studio it's the little
light on the top of the camera so the talent knows which camera to
look at. It can also be turned off ) I put 5 volts from 1 to 2 (neg)
and got the CRT to light up. If you open up the viewfinder you can
find which pin goes to the LED that would be 4.
I just use wires out of a Cat5 cable and shove them into the connector
for testing. You could find one of the mating blocks (male) off some
salvaged board (like junked VCR) and just cut out 4 pins mod it and
plug it into this cable then you could solder your own cable up.
Oh everything in this camera is NTSC EIA . Maybe I can play with it
more tomorrow.
Richard