Greetings Everyone,

I have taken quite a leave of absence from this forum, as I was set for a long while after getting my 19" tin can Zenith (Model K2109U, Chassis 16K27) set up on an antenna. However, I thought I'd get a little cocky (and ironic) after spotting a Roku stick on sale around Christmas time. I have an adapter that converts the little red, white, and yellow AV trio on the back of my converter box into an HDMI port. Once I plug all three of them in however, the picture vibrates inconsolably both up and down and side to side. No twisting of any of the picture controls gets it to steady.

I am FAR from an electronics expert or enthusiast, which is why I exclusively buy 1960s Zenith products, as in my experience they are indestructible and oftentimes require nothing more than a dusting off to work.

Is there something as too much converting/adapting which is making the signals go haywire or something? Is it even possible to pair such new and old electronics or is my ironic attempt to watch Netflix on a 60 year old B&W television in vain?

Any help or advice would be more than welcome.

I am not sure what you have but unless the set has been
modified you need a modulator. That will take the 3 RCA jacks & convert it
to run on channel 3 or 4. You can run a DVD also with it.
Second issue is compatability. The only add on at the time was a UHF converter. Newer add ons often have sync problems. And if you are
coming in on the antenna try the AGC control & see if it helps. It
may be to high.

73 Zeno:smoke:
LFOD !

It would be good if you described your signal chain better.
I'm guessing based on your text your signal chain looks like: roku->HDMI to Composite audio/video adapter box-> ATSC DTV tuner box-> TV set.

That setup, if it's what you are running, should NOT work at all. The ATSC DTV box's RCA jacks are OUTPUT ONLY. You should never try to back feed signal into them from another signal source device (ie don't use them as an input because they are NOT an input).

Replace the DTV box in that chain with an RF modulator to make the Roku work...Or if you have multiple HD and SD TVs in your house that you want to share the Roku, and don't mind spending $200-300 to make that work, you could get a ATSC DTV modulator (pick one with better than 40dBmV output), plug a UHF antenna and a Roku into it then tune it's OTA signal on your DTV tuner for the Zenith and on your HD TVs...I ended up doing a more complicated version of this with multiple HDMI source devices through a switcher box for various reasons that I explain in these 2 videos.
https://m.youtube.com/watch?v=hKjt3x4WtWU
https://m.youtube.com/watch?v=j1iN4ULZcX4

If you go with the more affordable option of just swap the DTV converter box for an RF modulator you will probably be annoyed that you have to unhook the TV from the modulator and switch it to the DTV box and vice versa when you want to switch source devices....My recommendation is to get a composite audio video switch box feed the RCA outputs of your DTV box into one input and the RCA outputs of your HDMI to composite adapter into another input then feed the output of the switch box to your RF modulators RCA input and use the switch box.

One thing that sucks about folks my generation and younger is that unless you grew up with older component stereo systems (like me) or your family was into home theater/game consoles and let you wire stuff for that the concepts of one way analog signal flow from jacks and inputs, outputs, splitters and switchers are all alien to you and need to be understood to prevent miswiring a signal chain and or multiple component video source system.

It would be good if you described your signal chain better.
I'm guessing based on your text your signal chain looks like: roku->HDMI to Composite audio/video adapter box-> ATSC DTV tuner box-> TV set.

That setup, if it's what you are running, should NOT work at all. The ATSC DTV box's RCA jacks are OUTPUT ONLY. You should never try to back feed signal into them from another signal source device (ie don't use them as an input because they are NOT an input).

Replace the DTV box in that chain with an RF modulator to make the Roku work...Or if you have multiple HD and SD TVs in your house that you want to share the Roku, and don't mind spending $200-300 to make that work, you could get a ATSC DTV modulator (pick one with better than 40dBmV output), plug a UHF antenna and a Roku into it then tune it's OTA signal on your DTV tuner for the Zenith and on your HD TVs...I ended up doing a more complicated version of this with multiple HDMI source devices through a switcher box for various reasons that I explain in these 2 videos.
https://m.youtube.com/watch?v=hKjt3x4WtWU
https://m.youtube.com/watch?v=j1iN4ULZcX4

If you go with the more affordable option of just swap the DTV converter box for an RF modulator you will probably be annoyed that you have to unhook the TV from the modulator and switch it to the DTV box and vice versa when you want to switch source devices....My recommendation is to get a composite audio video switch box feed the RCA outputs of your DTV box into one input and the RCA outputs of your HDMI to composite adapter into another input then feed the output of the switch box to your RF modulators RCA input and use the switch box.

One thing that sucks about folks my generation and younger is that unless you grew up with older component stereo systems (like me) or your family was into home theater/game consoles and let you wire stuff for that the concepts of one way analog signal flow from jacks and inputs, outputs, splitters and switchers are all alien to you and need to be understood to prevent miswiring a signal chain and or multiple component video source system.

That is exactly my chain! RF Modulator is on its way. I'm currently only running this TV but that system for multiple is definitely intriguing and I may one day replicate it as more sets begin to make their way in.

That is exactly my chain! RF Modulator is on its way. I'm currently only running this TV but that system for multiple is definitely intriguing and I may one day replicate it as more sets begin to make their way in.

If those sets are all vintage the best thing to do is buy a Blonder Tongue AM60 agile RF modulator. The blonder tongue modulators have enough output power that you can transmit in analog to all your vintage TVs within a block radius. Because I have around 100 TVs spread across several rooms on different floors wireless transmission is far easier and cheaper than the spaghetti monster that is feeding wired signal to each TV....I think the most sets I ever had simultaneously hard wired to signal was 6 and it was less than ideal.

If those sets are all vintage the best thing to do is buy a Blonder Tongue AM60 agile RF modulator. The blonder tongue modulators have enough output power that you can transmit in analog to all your vintage TVs within a block radius. Because I have around 100 TVs spread across several rooms on different floors wireless transmission is far easier and cheaper than the spaghetti monster that is feeding wired signal to each TV....I think the most sets I ever had simultaneously hard wired to signal was 6 and it was less than ideal.

My goodness, quite the collection! I can only imagine what the spaghetti for those 6 looked like.

If those sets are all vintage the best thing to do is buy a Blonder Tongue AM60 agile RF modulator. The blonder tongue modulators have enough output power that you can transmit in analog to all your vintage TVs within a block radius. Because I have around 100 TVs spread across several rooms on different floors wireless transmission is far easier and cheaper than the spaghetti monster that is feeding wired signal to each TV....I think the most sets I ever had simultaneously hard wired to signal was 6 and it was less than ideal.

:yes:Precisely what freed me from the coax octopus, was this modulator or similar product by Holland, MaCom, etc. Its hit or miss buying one on da' bay based on fixed channels, but those are cheap! Make sure you don't pick a VHF channel that is active in your area.

:thmbsp: This is also a good deal ( I have 3-7-11-12 for VHF ) and fine for you, it is channel 3!

https://www.ebay.com/itm/374332951566?hash=item5727fb8c0e:g:GV4AAOSwWWRjUaj r&amdata=enc%3AAQAHAAAAoKfjNPwE53A%2BXy59tiIbe1JVlFC y25B3uR%2BEoVviDEv6%2FywXsl9qnmHkGNg89sqCrSdVWww7p F8mkWMLSRW317ZmiN6qYz5uqIw8zChqfwrp9BJbdITb3GqFGM4 XakrWKuvlDixYVRN%2F7ByjAC7pR%2BJNB%2FAYwiw7%2FfGqd WeFqaRJjVCyp66rl6M7dwvxKg9YWx7wpwJOJ%2FQL4I5WWcVnc 7s%3D%7Ctkp%3ABk9SR9ziscezYQ

Here is an example of a fixed-output filter (non-agile) sub-chassis, cheap because it is for CABLE channel 19 and of no use to amateur broadcasters. I do have a channel 45 (analog) for my UHF sets, that happens to correspond to cable channel 94. If using a channel 66 fr'instance, that is analog 14, start of UHF band.
https://www.ebay.com/itm/285099453857?hash=item4261406da1:g:nwoAAOSwf8tiNLO 5&amdata=enc%3AAQAHAAAAsNFYrQzE%2B2Rz6ROxipbBHGpFRxW vXeE1Qs8OhRdTXWhREdkig85Wsk7s8yT3ULu4YGEpRMFKYu5ti 6WYIgNbWpwFueOUGHEm3%2BTkaXuZah7lAhy%2F6N6vuMVGdaX Jab1d8rv5QUw74CK3ti1Fdb9u%2FlhvOc38j23DR20RUtyOeS7 PQ7KpmQroWJjWuxljf1v4kfEyk6oCL3KP9MYsi0B6xy7vEhx19 GXJcp784G6s5Fkt%7Ctkp%3ABk9SR7irysazYQ

Thanks for all the help guys! My RF modulator came in today and is hooked up. It's doing rather well, other than some fine tuning on the back of the set that I'll get to soon.