Need an RF modulator adapter to use existing video switch for non Digital TV

Is this what you would need?

https://www.amazon.com/Adapter-Converter-Antenna-Display-Surveillance/dp/B0BKFP4MWX/ref=asc_df_B0BKFP4MWX/?tag=hyprod-20&linkCode=df0&hvadid=652483943168&hvpos=&hvnetw=g&hvrand=572330049275467086&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9027198&hvtargid=pla-2093165131364&th=1

If I can speculate.  You have a TV that is controlled or you use your “Video Switch” for.  That technology is past antiquated.  Now, I’m not some computer kid, and am 78 YO, but have a bit of knowledge and such.

Your TV may actually work with the NEW DirecTV box.  But, I can’t say for certain.  Monaco was usually “good” about installing nice electronics.  Background, you have a 2007 TV, probably actually manufactured in 2006.  In 2009, the US totally switched over to ALL digital.  However, there were TV’s made earlier that would work on Digital.  Your Video selector switch , PROBABLY requires you to set the TV Channel to Channel 3 or 4.  Then your OLD DirecTV box had all the cable channnls and such.  BUT….the cable box had a “built in” little TV transmitter.  Whatever you watched, was “comverted” to the OLD Channel 3 or maybe 4.  So, you set the TV and tuned it to Channel 3.  The. The DirecTV box took that channel, say ESPN, and converted it to Channel 3.  Then, you TV worked or displayed it as a Channel 3 signal….SO….you CHANGE  channels on DirecTV….not on your TV.  The TV don’t know the difference.  

OK…you got a NEW BOX.  It is DIGITAL.  It sends out a digital signal.  The HDMI is an INPUT to the TV.  It is NOT an Analog Channel 3.  Your video switcher was a “helper” that many used who did not understand switching inputs on a TV…it CONFUSED them,  

BUT…as digital TV’s came in and folks wanted sharper picture and better sounds….the technology changed.  This is your dilemma….

There is a “device” or adapter that MIGHT work.  The one suggested, I think, will not.  Amazon sells it.  Look at the screen shot below.  It takes a HDMI signal and then “runs it” through a device called an RF Modulator.  That destroys all the clarity and resolution, but it is also a “Mini TV Transmitter”.  It will convert thr HDMI signal into an old fashioned RF or “broadcast Channel 3”….probably the same as your older or original DirecTV box did.  No one wants the low quality Channel 3 Broadcast or Analog Channel 3….so, DirecTV stopped making them.  You can try this.  You have to run a HDMI cable to it.  Then you run the Coax to whatever input that the old DirecTV used.  In THEORY….that box will convert the HDMI to Channel 3 (or maybe 4) and it should work.

There are a few questions that I would ask????  How do you watch broadcast or Over The Air (OTA) TV now…You may have one of the older converter boxes…where you have to tune the OTA to a digital signal, BUT you still leave your TV on Channel 3.

The NEXT THING.  What “auxiliary” inputs does your TV have….that assumes you have NOT replaced the 17 year old TV.  If you replaced it, why are you using a Video Switch that was never designed or intended to work with a Digital TV.

If you have different inputs on the TV, the easiest is to get an adapter and turn the TV to “Input 1” or 2 or whatever.  There are many different ones.  The age, if your TV is original, would have had Composite….Red and White Audio and a Yellow Video.  Then ONE connector called S video…and finally Component Video.

If you have the manual for your TV, it will tell you.  If you take picture of the back and post it, then you can get an adapter from HDMI to say, Composite Video or S Video or Component.  ALL MUCH HIGHER resolution that. Browdcasting over channel 3.

I thank all that replied to my problem with replacing old Direct TV box to the new box .  

Old box had coax input and output.

New box has only HDMI output.

Well the Direct TV Technician came back with a Modulator Coax Adapter similar to was was suggested by Tom Cherry and Bill R.

I Now everything works as it should I have Satellite and off Air reception at both TV's and a much better picture then what I had with the older style box.

I thank you all for the quick response to my dilemma.