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Does anyone have recommendations for a specific inexpensive RF demodulator that's higher quality than your standard VCR (and maybe a little bit smaller)? Like any old equipment floating around that could do it? I have access to a lot of junk that's regularly trashed at work, but there's so much different AV equipment that I wouldn't know what to look for. I haven't found a high quality standalone RF demodulator yet that's reasonably priced IMO.

My personal experience with demodulators in VCRs hasn't been favorable, but if anyone has a specific brand/model they like, that would be helpful. I'm looking to get an Atari 2600's picture quality as clean as possible without doing an RGB conversion and modding it (not that I can't, but I prefer to keep it in factory condition). I understand that I'm not going to get 4k resolution and a 1600000:1 contrast ratio from something through RF; just wanting decent picture. I am running this through to a 1080p TV so having a 16:9 mode available would be nice. I have HDMI, composite and component options.

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    For those unfamiliar with the term "RF demodulator", these are also known as TV tuners, more specifically in this case SDTV tuners. Since TV's had tuners built-in, these were relatively uncommon but not unheard of. I remember there used to be one marketed years ago (1980's) that let you watch TV on a Commodore 1701 monitor, but at the price it was sold at, I doubt it did any better than using a VCR. – Ken Gober Dec 23 '16 at 5:36
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    Your first sentence suggests that you are asking where to purchase a demodulator - that would be off topic. The rest of the post asks what to look for - that is a good question. – Chenmunka Dec 23 '16 at 8:46
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    Do you have any objection to modifying your 2600 and grabbing the composite video before it gets to the RF modulator? – Blrfl Dec 24 '16 at 14:00
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    A typical VCR will have an RF modulator that should work decently when given a strong signal. If the picture quality from the 2600 isn't acceptable, replacing the switch-box with an RCA-to-coax adapter may help some if you haven't already done that. If you have done that, you may have to adjust the calibration on the 2600's RF modulator, and if that doesn't work you'll simply have to live with the fact that the 2600's RF modulator circuit isn't very good. – supercat Jan 25 '17 at 22:19
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    @montag: The nastiness stems from the fact that the Atari 2600 uses a cheap six-transistor circuit with a single tuning coil to act as an RF modulator. See atariage.com/2600/archives/schematics/… for a schematic. The design will likely generate a cleaner signal when the switch is in the "A" position (I'm not sure which channel that is), and adjusting the tuning coil may help it further. – supercat Jan 26 '17 at 21:11
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Although a VCR would have worked, I couldn't get my hands on one for free and I wanted to avoid the amount of space it took up.

I ended up grabbing some mystery units they were throwing away at work. At a glance I was optimistic they'd do what I needed, and I turned out to be right.

I grabbed a 232-MTA S12 Mono TV Tuner box made by Contemporary Research. It's about 6" x 3" x 2" and has channel changer buttons on the front with a 3 digit analog display to display the channel. I leave that on 3. The back output consists of a serial IO port (RS-232), probably for telnet configs or something), and a 12 V 350 mA dc power input with positive right polarity. Model appears to be 331-5017-112. It works great with my 2600 and it's not obvious to me that it's running through there instead of into the back of a TV (e.g. no extra interference). I use a tiny RF cable to Coax adapter I bought from eBay many years ago for $3 that seem to work pretty well in conjunction with it.

I also grabbed a 232-STS Stereo TV Tuner with S-Video output and closed captioning with what looks like IR input and is more or less visually identical. This one outputs in both S-Video and gold-plated RCA video instead of just rca like the mono device, and 475 mA/12 V instead of 350. The audio out is a five pin connector. I prefer the standard RCA out so I went with the mono device for now and have not tested the STS, although I would expect it to work just as well.

Overall, I'm very happy with my setup. I sure I'll spend most of my time using a Lakka box and emulating 2600 games, but I'll keep this around for show for certain. Pretty cool to see something working on an HD TV that was built 40 years ago.

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