On Sat, 28 Oct 2017 11:56:22 -0500, tb wrote:

I have found this old (1990!!) TV that was sold by Montgomery Ward USA.
The brand on the TV is "Signature 2000".

Looks like you have to search by
company = ward
and
model = Signature 2000.
DirecTV remotes have a 5 digit code in their remote.
http://www.directv.com/DTVAPP/global/contentPageIF.jsp?assetId=P4380052#h:620.226

Here's page full of Signature 2000 remotes:
https://www.replacementremotes.com/SIGNATURE-2000/Remote-Controls/
https://www.replacementremotes.com/store/prodthumbs?ns=1&producttype=Remote+Control&categor yid=176&keyword=signature+2000

I also have an RCA digital TV converter box (the brand is "RCA DTA800")
that comes with its remote. There is no specific part number on the RCA
remote.

Try RC27A remote:
https://www.replacementremotes.com/rca/buy-rc27a-dta800b1-digital-tv-tuner-converter-box-remote-control

I'm trying to pair up the RCA remote to the TV set. I tried the
following 3-digit codes that I found online: 000, 001, 023, 083, 115.
None of them work...

Does anyone know what the 3-digit code is?

Again, from DirecTV remote codes:
http://www.directv.com/DTVAPP/global/contentPageIF.jsp?assetId=P4380052#h:620.462
Also click on "find more codes".
--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558