Your TV has a MAXIMUM resolution of 480i. This means it only, ONLY, has the capabilities to display 480 horizontal lines by displaying 240 lines the first 1/60th (of a second) and then the other 240 lines the second 1/60th. 480i is REGULAR tv. It is the same picture that has been supported by every TV in the last 50 years, or so I believe. There is no way to make your TV display more lines of resolution. It's simply not possible. So any converter you think you know about is not going to improve your picture quality AT ALL. It won't even work. To be honest, it seems you are using component cables, and it was a waste of money to buy those in the first place, since S-Video will suit your needs fine.
So no, your TV is not HD, nor will it ever be, regardless of any wonder-converter you may come across. In fact, you could have saved alot of money if you had not bought the hk-7300, since the faroudja chip is currently worthless to you. If you can still return that, you might want to.. and find something that will upconvert any signal to be displayed over S-video or Component, without the de-interlacing feature. The HK AVR-635 would suit your needs, or any models from last year by yamaha, denon, or pioneer should work as well.