Westinghouse K840CK15 Restoration

[etype2]


September 24, 2024

Progress report 5 years after the completion of restoration by Mike Doyle and myself of our Westinghouse H840CK15 color set purchased at the 2018 Early Television Foundation annual convention and auction.

We set up our Sony A6300 camera on a tripod about 5 feet from the set in a darkened room during daylight hours over the past several days. Shot in RAW, 24 megapixels, focal length was set at 42 mm, aperture 6.5, shutter speed 1/15 second, ISO 1250. Developed by Lightroom for iPad, in TIFF, 16 bit, P3 color format compatible for my iPad display. The images were then cropped and dumbed down to JPEG to lower file size.

After initial setup adjustments 5 years ago, the service and user controls were never touched, nor did I open the cabinet. I just switch the set on and adjust the volume, that’s it. The channel is set to 3 for the digital ota converter box. The set is remarkably stable and does not drift. The set has developed grungy noise in the audio which comes and goes and a purity issue in the lower right hand corner. The vertical linearity at the top of the screen was there from the beginning and could not be eliminated. The CRT appears to as bright as when we purchased the set which has good emissions.

Only shot random broadcast images from NBC, CBS, FOX, and PBS. The white specks are window reflections. Video presents 8 new screenshots.

AFTER FIVE YEARS

https://videopress.com/v/4sZNjfNI

If you want to see the complete restoration, Part one: https://visions4netjournal.com/westinghouse/
Part2: https://visions4netjournal.com/westi...r-tv-part-two/

[etype2]

Happy Thanksgiving.

November 28, 2024
Screenshots of the 2024 Macy Thanksgiving Day Parade taken from my 1954 Westinghouse H840CK15.

[old_tv_nut]

Beautiful! Thanks!

[Steve D.]

Hey Marshall,

Still the best looking CT-100 around. Fantastic images. My CT-100 is still down for the count. No raster but great sound. The 15GP filaments are bright but have no way of checking the CRT.

[etype2]

Steve,

Does Steve K. Live in your neck of the woods? Thought he did. Maybe he or someone could troubleshoot your set.

My set is a Westy H840CK15. Thanks.

[Steve D.]

Hey Marshall,

I haven't been in touch with Steve K. for several years. And will probably try to spread a wider net to see if there is anyone in the So. Ca. area with the expertise to work on a CT-100. Most of those folks I used to know have, sadly, left us.

Thanks for the reply,
-Steve D.

[Penthode]

The Westy does not use IQ chroma demodulation and uses an narrower equiband decoder. From the photos I think the pictures benefit from the wider color gamut due to the 15GP22 phosphors and less to the chroma resolution. The luma resolution for both the CT100 and Westy are about the same.

Thanks for sharing the gorgeous pictures.

FYI, my CT100 has been down for the past year due to the failure of the convergence transformer. Have put off testing my final all electronic convergence transformer substitution solution which I hope to proceed with this month.

[etype2]

Originally Posted by Penthode

The Westy does not use IQ chroma demodulation and uses an narrower equiband decoder. From the photos I think the pictures benefit from the wider color gamut due to the 15GP22 phosphors and less to the chroma resolution. The luma resolution for both the CT100 and Westy are about the same.

Thanks for sharing the gorgeous pictures.

FYI, my CT100 has been down for the past year due to the failure of the convergence transformer. Have put off testing my final all electronic convergence transformer substitution solution which I hope to proceed with this month.

Thank you.

Anxious to see the results of your transformer substitution. Notorious failure, that transformer.

BTW. I’m particularly proud of this screenshot from the 1948 movie “The Red Shoes” as captured from this Westy with 15GP22.

[etype2]

Happy Holidays to all.

Here, a few holiday screenshots taken this month from the Westinghouse H840CK15.



A work I did for the holiday.

[etype2]

Happy New Year to all.

2025 Rose Parade on a 1954 Westinghouse color tv.

[old_tv_nut]

Beautiful!
Happy New Year!

[ChrisW6ATV]

Very impressive indeed!

[etype2]

Posted March 3, 2025

A few screenshots from last night’s live Academy Award show on a Westinghouse H840CK15.

[oldtvman]

Are there any visual comparisons between the CT 100 and the Westinghouse?

[etype2]

Originally Posted by oldtvman

Are there any visual comparisons between the CT 100 and the Westinghouse?

Difficult to answer. Do you mean a characteristic common to one and not the other?

The CT100 is said to have a superior color demond circuit, beyond that, I’m not aware of design philosophy in the Westinghouse or RCA that make a difference, however this video states the Westy has no crystal oscillator and a few other differences. https://videos.files.wordpress.com/H...-rca-ct100.mov (Mt set does not drift) All things being equal, I think it largely depends on the original build quality at the factory and quality control. Some 15GP22’s suffer vacuum leaks, while others do not.

I think ultimate picture/color quality depends on the quality of the restoration/calibration.