Adapting an old CRT Viewfinder ( 9.3 V DC / 2.7W )

Thread Starter

nickhess

Joined Dec 9, 2018
4
Quarantine project: Adapting a Sony BFV-20W viewfinder

Scroll down to skip the background info

As a cinematographer, I've always really felt most comfortable shooting with a viewfinder. However modern electronic viewfinders all exist in the "prohibitively expensive" class of filmmaking equipment. But I own a couple of older cameras with black and white CRT viewfinders which have always been more than comfortable and capable. SO I did a little digging and turns out those little CRT's are being adapted here and there to run like little monitors.

There were some doubts at first, some questions needed answers,

"can I find an older viewfinder capable of 16:9?"
"how sharp/pixel-dense could I expect a little monitor to be?"
"can I go for color or is that a stretch?"
Fast forward and I found the sony BFW-20W for a not insignificant sum but enough to justify it. Plus this just seemed like a fun challenge for the time being as well as an excuse to learn some electronics. I've been watching videos like bigclivedotcom and 12voltsvids for a while but I'm a complete beginner, I could use some help.

The Sony BFW - 20W ( manual )
Specs from the listing
listing specs
Specs from original manual
Screen Shot 2020-05-13 at 11.18.17 AM.png
From what I understand so far, converting the right signal wire to a standard RCA type connecter should work fine and shouldn't be too complicated. It's the power requirements that have me looking for help. I noticed a discrepancy between the listing (2.7 W) and the manual's wattage (2.3 W) but the voltage on both remains 9.3 v .

From what I understand, I cannot overshoot or undershoot that 9.3 v number or things get dangerous. I've just had a little trouble finding the information about how to go from a 12v dc source to a 9.3v dc connection.

Because this viewfinder seems to have a higher than the typical power requirement for these littles CRT's, I think I can't reference a lot of the videos out there. Wherein USB is the main power delivery method. Instead, I'm intending to use something like this: Power Tap D Tap to 2.1 DC 12v Screen Shot 2020-05-13 at 11.03.37 AM.png

which will be attached to a battery plate with this description:

Screen Shot 2020-05-13 at 11.03.58 AM.png

so that's where I am so far, let me know if I can provide any more info.

I really appreciate any and all help. Completely new to practical electronic stuff so I invite all feedback and ideas

Thanks in advance!
-Nick
 
Last edited:
Top