03-07-2024, 08:44 PM
I've fitted a new 7525 chip and removed the bodge board. It works.
www.borinsky.co.uk Jeffrey Borinsky www.becg.tv
Philips PM5544 electronic testcard
|
03-07-2024, 08:44 PM
I've fitted a new 7525 chip and removed the bodge board. It works.
www.borinsky.co.uk Jeffrey Borinsky www.becg.tv
05-07-2024, 07:28 PM
(This post was last modified: 05-07-2024, 07:30 PM by pamphonica.)
Jeffrey, wonderful work!
I am showing 3x 7474 original type in stock. You are welcome to a couple if that helps you. ditto 4x 7402 if you need those. all best Jeremy
Jeremy. G8MLK. BVWS Secretary. British Vintage Wireless and TV Museum Friend.
Pamphonic Website ______________ BTTT OB Truck Restoration
05-07-2024, 09:42 PM
Many thanks for the kind offer. I found enough LS parts to make it all work.
www.borinsky.co.uk Jeffrey Borinsky www.becg.tv
10-07-2024, 03:53 PM
It's now installed in the museum's Central Apparatus Room. The Y/B-Y/R-Y output is connected to an analogue to SDI converter. The RGB output to a PAL coder. This Vistek design is a very good unit with comb filtering but the luma/chroma delay is wrong. I hope we've got the manual somewhere.
www.borinsky.co.uk Jeffrey Borinsky www.becg.tv
07-09-2024, 09:56 AM
@ppppenguin (or anyone else)
I have a PM5544 with core type memory that I'm trying to get back in working order and I also seem to have a bad SN7525N chip. I'm not as skilled as you are when it comes to designing circuits, would it be possible for you to share a rough schematic of your working 7525 replacement with the LM319 comparator and 74LS08 gate?
07-09-2024, 11:54 AM
Here are my notes on the 7525 substitute. It's a lot easier to buy some, even though it will be relatively expensive.
Good luck with the restoration.
www.borinsky.co.uk Jeffrey Borinsky www.becg.tv
|
Users browsing this thread: |
1 Guest(s) |