While RF is no great shakes when it comes to quality for any system, I have noticed that my NES's RF has significantly superior video quality to my Famicom's RF. Jailbars from the Famicom aside, the HVC-CPU-07's Famicom's picture is either softer or grittier than the NES-CPU-10 NES's picture.
Since I live in the US, the NES's RF modulator is fixed to US TV channels 3 and 4 (60MHz and 66MHz, respectively). Back in the days of analog TV broadcasting, I typically always kept my consoles set to channel 3 because nothing in my area used it outside the cable box. Channel 4 was assigned to the local NBC or CBS affiliate. The choice was there for people who found a better signal from the other channel. Now use digital TV broadcasting, I do not perceive a quality difference at either channel. Digital TV transmission, even though it uses the same frequencies, does not appear to interfere with the signal sent by the NES to any substantial degree.
As we all know, the Famicom's RF modulator is fixed to Japanese TV channels 1 and 2 (90MHz and 96Mhz). In the US, these are used by FM radio stations. US TVs did not used to support these frequencies, and apparently they were assigned to cable boxes but were infrequently used due to the overlap with FM radio. Within the 6MHz band required by a TV signal, you get 30 FM radio channel frequency assignments. Instead of one digital frequency, you can get bombarded by multiple analog frequencies. Some are more powerful than others, but between the RF modulator and the TV's demoulation circuitry there must be some extra interference coming from the more familiar analog signal of the radio stations. Does this make sense?
Since I live in the US, the NES's RF modulator is fixed to US TV channels 3 and 4 (60MHz and 66MHz, respectively). Back in the days of analog TV broadcasting, I typically always kept my consoles set to channel 3 because nothing in my area used it outside the cable box. Channel 4 was assigned to the local NBC or CBS affiliate. The choice was there for people who found a better signal from the other channel. Now use digital TV broadcasting, I do not perceive a quality difference at either channel. Digital TV transmission, even though it uses the same frequencies, does not appear to interfere with the signal sent by the NES to any substantial degree.
As we all know, the Famicom's RF modulator is fixed to Japanese TV channels 1 and 2 (90MHz and 96Mhz). In the US, these are used by FM radio stations. US TVs did not used to support these frequencies, and apparently they were assigned to cable boxes but were infrequently used due to the overlap with FM radio. Within the 6MHz band required by a TV signal, you get 30 FM radio channel frequency assignments. Instead of one digital frequency, you can get bombarded by multiple analog frequencies. Some are more powerful than others, but between the RF modulator and the TV's demoulation circuitry there must be some extra interference coming from the more familiar analog signal of the radio stations. Does this make sense?