Admiral model 24R12, Diagram

See the Yanks win the Y2K pennant, and then play the Mets in the Subway Series, on the Admiral set

A VHF only classic: RCA Victor 1957 model "The Cooper".

Careful when you remove the chassis that you don't drop it and bust off the CRT's neck!

Dial from the TV we watched the first moonwalk on (Apollo 11).

vacuum tube sets, above,
and right is a Motorola hybrid

A Westinghouse TV cabinet, 25 inch B&W set. Also a GE cabinet. And a complete GE compactron TV. And an all tube Zenith.

What the Westinghouse set would look like, showing Wilma and Fred Fliststone smoking Winston cigarettes.

Back in the days when the NTSC color TV system was being developed, a test color transmission of some fruit was done. Some practical joker took the bananas and painted them blue. In the NTSC color system, the color (more precisely chroma) is encoded onto a subcarrier, the phase indicating which color. Yellow 180° out of phase yields blue. The guy at the receiving test site would adjust the phase (commonly called "tint") to get the bananas right, but then the rest of the fruit would be wrong!

A similar error happened to this weatherman, who here looks like a Smurf. The chroma subcarrier from the camera looking at the weatherman got flipped, to become 180° out of phase compared to the chroma subcarrier of the weather map graphics. Like bananas, flesh tone color (which is close to being yellow) will look blue when the chroma subcarrier is 180° out of phase.

Solid state sets, below:

This is not its remote, but it went with
this on the right RCA set, a CTC101 chassis: . Marketing named it the "Symetra", FD498R, included a luma-chroma comb filter with vertical peaking (marketing called it a "Dynamic Detail Processor"), fake stereo "Dual Dimension Sound" feeding speakers on both sides of the CRT, and a PLL tuner.

Back in the its day, a co-inventor Hermann Weckenbrock and myself at RCA Labs, and proof of concept equipment we built to show how well our NTSC chroma-luma frame comb separator worked. We used modified CTC121s that accepted what we'd call today S-video (or maybe it was Y Pr Pb, or RGB, been a while, someone else built the chroma demod and color matrix circuits, I did the frame comb filter with motion correction) as displays. You can tell from my skinny tie that this was in the 80's. Today all this roomful of stuff would fit inside a chip in a smartphone.

Modern sets:
Panasonic plasma TC-P50GT50 manufactured October 2012

Watching the game on TV:

Watch vintage movies and TV shows on your vintage B&W TV set from your DVD player using a TV channel modulator: Connect the Luma video from the DVD player to the video input of the modulator. Use of the Luma video signal avoids the chroma interference the composite video would have on the B&W TV. Connect one of the audio outputs from the DVD player to the audio input of the modulator. Connect the B&W TV antenna input to the RF output "F" connector of the modulator, and you should be able to tune in the DVD movie on channel 3 or 4, depending on the setting on the modulator. Macrovision on the DVD movie may confuse a VCR's video input circuitry, making its modulator output unusable.

Apex AD3201. This DVD player has a hidden menu.
To access:
Eject the tray, then press the numbers 8, 4, 2, then 1 on the remote. Dashes should appear on the screen for the first 3 numbers, then the hidden menu should then appear upon pressing the last number. Use the ^ and v keys on the remote to select "region" or "macrovision". Use "enter" to step thru which region you want (9 is "all" or "bypass") and if you want macrovision or not. Macrovision may make some vintage TVs or VCR channel modulators unhappy. To save the settings, close the disc tray. You can now use the "Y" video output to feed a B&W TV set via a VCR, as it will not have the color subcarrier and macrovision on it.

HDTV antennas?
Back in the early 1960's, someone installed B&W TV sets in every classroom of my grammar school. Likely a GE VHF only model. This was around the time educational TV stations went on the air. Our local station was Channel 13 of NYC. The teachers never used the TV sets. Note that the TV is in the back of the classroom! Teachers hated TV anyway (they wanted us to spend all our evenings studying and doing homework).

This was from a TV with separate VHF and UHF tuners. The motel had a VHF master antenna system and no UHF antenna, so they changed the UHF knob to this one with their logo...
Over the air subscription TV decoder box, remember these?
This one went with "Wometco Home Theatre" on channel 68 NYC. Channel 68 then played music videos in the clear (U68), then home shopping, and now is a Spanish HDTV station using virtual channel 68.

Pirate TV station in Syracuse back in 1978:

In the local paper:

Prefiltered S-video to composite for better pics on vintage color TVs

On a vintage color TV, they didn't have comb filters, but only "notch" 3.58MHz bandstop and bandpass filters for chroma-luma separation. This assumed that anything above 3 MHz on the demodulated composite video signal belonged to the chroma subcarrier. Problem is that any fine detail in the luma ends up as crawling rainbow colors on the CRT. Later low end color TVs also did this.

But, if I have a source of S-video (separate luma and chroma, like on a better HDTV converter box or cable box), I can prefilter the luma (bandstop) and prefilter the chroma (bandpass) so no fine detail luma exists anymore, and thus won't become crawling rainbows on a vintage, or a later production notch filter TV set.

The circuit:
Frequency and group delay responses:
The values of the parts are not that critical. The resulting prefiltered composite video then feeds a TV modulator to send to your vintage color TV set.
Your set will present better looking pictures. Feeding a VCR with this prefiltered composite video, for recording, will make for better looking videotapes as well.

If I owned a TV station in the 60's and 70's (before comb filters were used in consumer TV sets) I would have done this prefiltering in the equipment that encodes the chroma and luma to become the composite video before it's transmitted. "Football games always look better on your station", fans might have said.

I used a combo composite and Svideo jack I salvaged out of a dead DVD player to build this filter on. The cap lead with the red sleeve here is the chroma.

You could install a TV modulator inside a DVD player. I used channel 3 to avoid the 5th harmonic of the DVD video sampling clock, which lands in channel 4. To avoid noise, use a local voltage regulator, caps and a coil to filter the modulator's B+. Place these parts right at the modulator. Check that the video feeding the modulator isn't too much amplitude, you may need a voltage divider (video signal source impedance and resistor "R") to get it to a level the modulator will be linear with. Use shielded wire for the audio and video input feeds. Most modulators also have a "TV/VCR" control line to switch from an antenna feedthru to modulatoed video. If your DVD player's power supply is always on, and there's a control line from a microprocessor that listens to a "power" push button, you could grab any 5V power that switches on when the player is set to "on". You might need to invert this signal. The modulator's B+ via voltage regulator would be fed by constantly on power. If you don't want to do an antenna passthru, but just an RF output, just have B+ via voltage regulator to the modulator be turned on. And hardwire the "TV/VCR" line (you'd need to do it this way if the DVD player has a true power switch).
I used a switch on the video in line, to select either filtered composite video, or luma only (for use with B&W sets).
A better filter, abeit with more parts. Sharper stopbands, but poorer group delay. The 75Ω resistors represent the source impedances of luma and chroma in S-video sources. Simulated response curves (the source not being measured is shown as a 75Ω impedance to ground)

Modified a RCA XL100 CTC108 TV with a Channel Master CM7000 DTV CECB box that provides S-video inside the set's circuits feeding the luma and chroma downstream of where the chroma-luma separation circuit was

Had an older RCA XL100 TV set that used a mechanical click twist tuber (not a varactor or synthesized tuner). And had an extra Channel Master CM7000 CECB with S-video output. I decided to make this TV into a digital ATSC receiver by removing its old tuner and installing the CECB inside it. What this would do for me is to create a color TV set with no cross luma cross chroma defects (no false color crawlies on fine luma detail, and no crawling or hanging B&W dots on color transitions in the video image). What I worked hard at the RCA Sarnoff labs to reduce with the then broadcast analog NTSC TV signals. As the Channel master CM7000 provides S-video outputs (the luma and the chroma never having been merged together, thus no cross signal defects later). Downloaded the SAM's ($22 but was worth it to find my way around the TV circuits) and found the points to inject the S-video and the notch filter on the luma I'd want to remove. I did not use termination 75Ω resistors on the luma and the chroma signals, as the unterminated voltage levels are close to what I need, and any reflections off the unterminated coax ends would be absorbed by the source 75Ω resistors inside the CM7000. AKA "source termination". Paid attention to be sure the demodulated chroma would match the luma on the display screen CRT. I used a variable 0-317nsec video delay box to determine that I need an additional 90nsec delay on the luma. Seems the IF strip group delay response provided this before I modified this TV set. Also had to figure out how to get the audio into the sound IF demod and audio amp chip. To avoid deflection buzzes in the sound, I used an audio isolation transformer to break a ground loop (and carefully located and positioned the transformer mounting orientation for minimal deflection noise pickup).

Luma delay test setup to match chroma,
placed between the CM7000 and the CTC108 circuit board (the video line driver circuit is to buffer the delay line from the unterminated feed to the CTC108 board)

And just got the 30nSec 100Ω analog delay lines. 3 of them in series gives me 90nSec of delay. The delay likes are 100Ω impedance, so I added a 24Ω resistor to the video source to make the video be 100Ω. The few inches of 75Ω cable from the CM7000's S-video jack to this circuit is of no consequence. And the delay lines terminate with 100Ω, then the video buffer line driver makes it 75Ω impedance again.
And what this buffer/delay line board looks like (I mounted it on the back of the CM7000).

And took a picture of the resulting display:
No cross luma or cross chroma problems, as these were never mixed together in the first place. Digital TV ATSC transmissions keep these signals separate.

More screen shots showing a lack of cross chroma, below a pattern on the collar that gets cross chroma with a line comb:

And below left is a football game down line graphic (green-yellow-green transitions), and right the football captain symbol on the uniform (blue-yellow-blue transitions), showing that the chroma-luma group delay timing is reasonably correct.

And a lack of cross chroma (look at the close together strips to the left of "Fox Sports") you'd get with a notch filter. And we have luma to around 4MHz too:

The CTC108 chassis is a "hot chassis" design, and here the CM7000 CECB becomes "hot" as well, so I used a special antenna RF coax connector that stops DC and low frequency AC, one designed tor this purpose ("hi-pot"), but lets pass 50MHz and above from the antenna to the box (which is now "hot" inside this modified set).

Archer video sound processor. It says "video", even though it processes audio only. But I use it to expand stereo sound, and it can make fake stereo from mono sources like a VCR or TV set. Or any other audio fed into the "VCR IN" jack. I ended up placing sticker lines to show the signal flow around the switches and knobs, as it took me a while to figure out the flow. Inside, I had to replace 1uF electrolytic non-polar caps, as one went almost open, and changed the rest figuring they would soon fail. They tested iffy. Used small films I had. Amazingly, it was made in USA!