Does anyone know what type of RF Adaptor will work with a MSX machine?

If you mean 'My MSX has a RF connector' then in most cases a standard RF cable will do the trick nicely.

RF is the true retro way of using MSX Superblurry pixels and washed out colors actually somehow improve gaming experience. But for sure you'll bleed from your eyes if you try to program with RF connection

I've used my NES one. All I get a bunch of static and a faint picture in the background. I've tried other methods like running a line straight to the back of my VCR RF jack, I used a speaker wire and RCA to RF adaptor. It doesn't do anything but static. Any suggestions? Do I have to use a RF line?

Sound like your MSX is on channel 2, and you use channel 3 or something like this. Unless RF coder is really damaged.

I got it to work. I had to turn to some crazy channel like 48 or 46 or something. Didn't really help my audio problem with Metal Gear 2 Solid Snake.

Why you don't use composite video? I don't think any of MSX computers didn't output composite. It's much better then RF

The NES RF-cable does not work fine on a msx.

Generally RF sucks, but many gamemakers relied on it to blur the sprite edges and make the graphics look smoother. I think that composite is the best option because you don't need to search for the correct channel and swap cables all the time. It also has some blur left so games can still take advantage from it, RGB, in my opinion, gives a too accurate picture on many old computers/consoles and makes the games look blocky.

Many new (under 5 years old) TV's also have problems with these old RF-based machines because their RF-tuners are much worse than in many old TV's as nowadays televisions usually only need to find the TV channels, all machines are plugged to the SCART socket. My own 28" wide screen Sony for example can't be used with any RF machines because the tuner is so bad. Commodore, Videopac, Atari 2600 and MSX can't be used at all (no stable picture) and Nintendo's and Sega's give out a very bad picture with lots of stripes, so i only use composite or RGB.

Hm, I never tried MSXes, but both NES and SMS work great via RF on channel 3. It's barely less sharp then composite. The TV is a cheap 27" Sony Wega from 2001. But the best part is how this TV works with S-Video input from Panasonic FS A1WSX and A1GT. It's so sharp, I can actually read mode 80 information. Not as good as upscanned RGB connected to CRT VGA monitor (TFTs suck).

Somehow I find blurines annoying. I like my pixels crisp and square

Indeed, there's nothing wrong with square pixels.