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Early Color Television

Restoring the RCA TK-41

We received a donation of TK-41 equipment, including three cameras and all the support equipment we need to restore our camera. So, we have decided to start the process of getting it working again. Here is technical information on the TK-41. Chuck Pharis is also restoring a TK-41.

Here is an outline of how we hope a approach it:

  • Clean all the support equipment (it was stored in a barn for years)
  • Have the equipment racks sand blasted and painted
  • Mount the support equipment for display
  • Find volunteers to recap the support equipment and ship the units to them
  • Connect the equipment and troubleshoot it

March 1-2, 2016

 

Here is the slant rack, after sand blasting and painting. The control panel and processing amplifier have been mounted. For now, a piece of black poster board is on the desk area. We will have a piece of black laminate cut.

The underside of the slant rack, showing the gain pots and the Variac/Barrier Strip

When the bottom metal piece is removed from this rack, it will be the same height as the rack for the color controls. It will have the TM-6 master monitor. To the left will be our TM-21 color monitor.

The tall rack, with (top to bottom) Colorplexer, Color Bar Generator, Calibration Pulse Generator, Centering Current Supply, Focus Current Regulator, and two WP-16 Power supplies.

March 5, 2016

We are seeking volunteers to recap and clean up units for the TK-41. Here is a list of what we need restored:

Unit Volunteer
WP-16 Power Supply (2) Steve McVoy (1)
Focus Current Regulator  
Centering Current Supply  
Colorplexer Phil Dudley
Color Bar Generator John Folsom
Calibration Pulse Generator  
Processor James O'Neal
Camera Upper Shelf Chassis  
Camera Vertical Deflection Chassis David Carlstrom
Camera Horizontal Deflection Chassis Steve Kissinger
Camera Viewfinder Dave May

These units will be available at the convention for you to take home with you. We will have documentation available. Contact us if you are interested in doing a unit.

The entire setup

Barry Bennett's Restoration Work:

Barry Bennett, who operates Bennett Systems, a manufacturer of television production vans Sunbury, OH (about 30 minutes from Hilliard), has agreed to complete the restoration of the TK-41 system. Barry worked on tube-type color cameras early in his career. Here is how he intends to tackle the project:

Having briefly glanced at some of the online manuals, that it might make some sense to start by just taking the rack and console equipment, and perhaps the cabling, and leave the camera head there for now.  I can get a good deal of the electronics working without the camera head, and I think it would be a good way to start.  At the same time I can complete the restoration of any of the electronics modules that have not yet been done.  I can work on the colorplexer with my own test signals, and THEN get the bar generator working ... and proceed like that until most of the support gear is all functioning. 

I can probably scrounge up an old equipment rack somewhere, or make one from the rails I have here, in order to leave the nice freshly painted racks at the museum.  Only last year I sent three perfectly good racks to the recycling plant  <sigh>

I am actually quite excited about being a part of this project, and looking forward to it. 

Phase two would move into getting the electronics in the head working, possibly on the bench at my shop without even needing the head.  More on that once I learn a bit about those systems.  Once I've got as much working as possible, only then would I move the camera head to my shop for the final phase.

What I'd like to do is pick up the manuals, assuming you've dug them out of their hiding place.  I'll spend a few days looking them over and decide where to start from there.  I can copy any of the pages I will be using heavily, such as schematics, to preserve the manuals.  I've got a large format copier at my shop and can create 11x17 documents and / or copies.

Barry's Progress:

August 30, 2017

Half of my shop getting set up to start work on the colorplexer.  I'd love to restore the 585 scope first and use it for the project but ... we'll see how energetic I get.  Probably start with the 2445 as my scope for starters.  While it is really cool to use vintage test gear to fix vintage equipment, constantly maintaining your test gear can get ... tedious.  We shall see...

Just the workbench.  Again, the big Hickok VTVM isn't restored yet but my intent was to do that first and use it to work on the TK41.  We'll see how much energy I have...........  probably for starters I'll just cave in and use the Beckman or the Fluke.

My entire workbench area, still under construction.  Aren't they all?

The colorplexer is almost ready to begin it's journey back to life.  Need just a few more tubes, and replace one tube socket that got damaged during its replacement.  Also need to fix a few things that are left over from the initial re-capping and tube socket replacement done by someone else (THANKS!!) that were damaged during the million years of storage of this unit.  There is a stuck multi position switch, a few components with broken wires, stuff like that... and thankfully clearly marked by the restorer of this chassis.

Then a million coax jumpers.  I got a bag full of UHF to BNC adapters, so all jumpers (at least during the restoration and testing phase) will be BNC for ease of connection, disconnection, cross connection, and testing.  In lieu of the RCA color bar generator (being restored by others)  I will use "fudged" test signals from my more modern equipment to get the colorplexer up and running initially.

Then, the smoke test!!  Decisions Decisions ...do I use the variac, or just flip the switch.

September 17, 2017

TK41 interconnect cables are power washed and drying.  From the closeup of the one connector, I think I have about decided to replace all of the cables and connectors with new.  The rubber jackets of the cables have either started to disintegrate, or are iron hard and inflexible.  Since the connectors are deteriorated beyond recovery for the most part, I think trying to salvage them may be an exercise in futility and lead to problems in the future.  I'll evaluate them one by one, but that's my initial impression from seeing what's left now that the dirt has been removed.