Panasonic WG-R2 "visual telecommunication system" repair

[cj_reha]

Over the weekend I attended a vintage computer workshop held at the System Source computer museum in Hunt Valley, MD (I highly recommend visiting, they have a very impressive collection on display!), and during the course of the workshop I ended up bringing home this cute little set to fix for the museum. It is apparently a teleconferencing device able to send video over the telephone line as well as via composite. They own two units, and this one did not turn on or display any signs of life.

The set was apparently plugged in with a 13.8V AC adapter, when the original adapter is a center negative DC supply, so I decided to first take a look at the power supply. That turned out to be easier said than done, as the entire power supply is enclosed in soldered-together shields also acting as a big ground plane. After about an hour I was finally able to free the power supply only to discover there was nothing wrong with it aside from a marginally testing electrolytic. The search continued..

I eventually found a diode in the horizontal circuit that tested completely shorted, but after desoldering, it seemed to test fine. I backtracked the circuit a bit and found the culprit: a .047uF film cap! The set works fine now, as can be seen in the photos.

Does anyone have information on these weird things? I couldn't find any manuals, schematics or anything on them aside from random eBay listings. I'd love to know more about them as they seem quite interesting but obscure little sets that IMO deserve more attention.

[MIPS]

It looks familiar to the Visitel units sold by Mitsubishi, however newer (CCD instead of newvicon pickup?) and the CRT is in landscape as opposed to Portrait.

If it does operate in the same manner otherwise, it is not a realtime videoconferencing device. When you press SEND the unit "steals" the telephone line for several seconds to transmit ONE frame of input video, then gives you back the ability to talk.

[old_tv_nut]

Neat gizmo. I assume we will get another report when they hook the two units to each other?

[cj_reha]

Originally Posted by old_tv_nut

Neat gizmo. I assume we will get another report when they hook the two units to each other?

Hopefully. I'm not sure when I'll be at the museum next, as I'm roughly five hours away, but I might ask the guy to send me a picture if and when they're all set up.

[MIPS]

Here's a 1988 issue of Popular Science that better covers how it works.

https://books.google.ca/books?id=yQA...page&q&f=false

[cj_reha]

Good news, the set made it back to the museum safe and sound! I got a nice email this afternoon with a picture of it working.

[old_tv_nut]

ooH Nice!