President CB Radio P channels
Some newer President CB radios including the Bill III FCC (FCC ID 2AEOCPC210, Model TXUS201) have preprogrammed FM mode with CTCSS squelch on “P channels”. Similar to some OEM FRS / GMRS radios that have preprogrammed channels with CTCSS or DCS codes, the P channels are a convenience that immediately allow users with CB radios having FM and CTCSS to interoperate with each other. We welcome preprogrammed P channel-like features with FM and CTCSS as they are likely to increase usage of FM mode and CTCSS on CB radios. This gives the benefits of maximum range with minimum interference. Before these preprogrammed channels, setting CB radio CTCSS coded squelch involved diving through menus.
The CB radio channel to President P channel mapping is:
| President P channel | CB channel | Center Frequency (MHz) |
|---|---|---|
| 1 | 1 | 26.965 |
| 2 | 3 | 26.985 |
| 3 | 11 | 27.085 |
| 4 | 18 | 27.175 |
| 5 | 24 | 27.235 |
We wonder if the P channel choices included user feedback or CB radio spectrum use observations. The commentary following is based on North American CB radio usage observations. The lower CB channels are historically less frequently used due in part to adjacent channel splatter from CB channel 6 and 11 that are partially used by DX operators. High power stations with clipped AM modulation that splatters adjacent channels have a lower duty cycle based on the human voice. Using FM mode with coded squelch experiences much less disturbance from adjacent channel splatter versus the AM mode with signal squelch.
- P channel 1 (CB channel 1) on FM mode may have less interference than the other P channels in many areas.
- P channel 2 (CB channel 3) is 40 kHz away from CB channel 6 with the highest power operators and is likely also as good as P channel 1 for interference.
- P channel 3 (CB channel 11) is a popular AM mode channel. FM users (even with coded squelch) may experience reduced communications range due to co-channel interference from AM mode users.
- P channel 4 (CB channel 18) is adjacent (10 kHz away) from CB channel 19, which is a popular AM mode channel for truckers and highway travel.
- P channel 5 (CB channel 24) may like P channels 1 and 2 have less interference than P channels 3 and 4.
Suggestions to President for future P channels
Although it may be impossible to change the existing radio P channel frequencies, we would suggest OEMs consider adding the P channel frequencies for future radios: CB channels 2, 8, 12, 27, 29. These frequencies avoid: DX users (CB channels 6, 11, 26, 28), handheld (CB channel 14), off-road users (CB channel 4), and SSB users (CB channels 16, 30-40).