No.
Is it possible to upscale my analog signal/basic cable through my onkyo 806. the onkyo does have a faroudja chip in it. I know the receiver does not have any coax input on the back, so i was thinking about maybe getting a RF adapter/modulator/ or some box that will input coax and output component/RCA.
even if ican get that device will it upscale.
Look at it like trying plug an FM antenna into the "aux" input of an amplifier.
What you have is a raw cable feed coming into your house which is, for all intents and purposes, a mish-mosh of all the channels coming through the cable.
You would first have to feed it through a tuner/cable box or whatever to get one channel of video and audio. From there, you might have a fighting chance of "upscaling" the video signal for the selected channel.
But, your TV has a built-in upscaler already so I wouldn't worry too much about it.
Like Skers 54 said, a basic VCR should do this for your basic analog cable but you'll have to do all your tuning through the VCR.