Need advice: fuzzy/blurry/snowy/static picture on recently purchased 7800

[atarichetc]

Hi! I recently purchased an Atari 7800 on Ebay. Unit came with an existing RCA cable. Had to purchase a power supply separately.

 

I purchased 1 of these to connect the unit to my LCD TV:

 

http://www.amazon.com/Intellivision-Colecovision-Adapter-VINTAGE-WITHOUT/dp/B0028MXOF6

 

After making the proper connections, I get a fuzzy picture similar to the first picture at this link:

 

http://www.atariage.com/forums/topic/173539-the-atari-7800-displays-a-blurry-image/

 

I made sure that the RF channel output on the Atari 7800 matched the same analog channel on the TV.

 

What can I do to improve the signal output? Could I be dealing with a bad RCA cable? Should I buy an RF demodulator (or find an old VCR) to try? Or, did I simply just purchase a defective unit?

 

Thank you to all replies.

[atarichetc]

OK, this is weird.

 

When I set the channel selector on the Atari 7800 to square (channel 3), I get a fuzzy picture from the 7800 on TV channel 2, but nothing on channel 3.

 

When I set the channel selector on the Atari 7800 to circle (channel 2), I get a fuzzy picture on TV channel 3, and not 2.

 

According to the online manual I have for the 7800, square is supposed to be for channel 3, and circle for channel 2. Is that right, or does my 7800 seem to have things in reverse?

[gorfcadet]

Do you have an old vcr you can run the signal through? Usually solves the problem without wasting money on a signal booster an then you can run it through a composite input (red/white/yellow) cables instead of coax. Most modern tvs have very poor built in tuners and this would allow you to avoid using that.

[gorfcadet]

signal booster... sorry stupid virtual keyboard.