Communications Equipment / Radios

mike-s wrote:

Gdetrailer wrote:
Per the FCC "rules" (and YOU of all folks should be painfully aware of them) has never allowed more than 5W (THAT IS FIVE WATT) INPUT power to the final output stage of ANY radios that were destined to be used on the 27 mhz CB "band"..

That 5W input to the finals due to losses in heat meant the absolutely highest output allowed was 4W FOUR WATTS to the antenna.

Not quite true. Originally, it was 5W input. Now, there is no limit to the input, only a 4W output limit. So, one could have an inefficient final with more than 5W input. And it wouldn't surprise me if some current cheap ones had more than 5W input. The old units with 5W input would sometimes only put out 3.5W. That's just for AM, of course, and the allowed 12W SSB would require more than 5W input (PEP, not average).

For AM, FOUR WATTS OUTPUT to the antenna at 100% modulation, but to GET the 4W at 100% modulation it TAKES FIVE WATTS of INPUT that the final stage will use at 100% modulation..

With no modulation, 3.5W IS the typical output, but remember, the modulation does have a limiter which is designed to never reach 100% modulation unless someone "mods" the unit... Tested some different CBs back in the 1980s, some limited the AM modulation as low as 35% and most were 50%-60% modulation.. You could scream as loud as you wanted and those limiters would not allow anymore modulation!

SSB is a hole nother animal, never really took off due to extra cost.. Some folks did figure out how to "peak" some models of SSB units to open them up to more than 4W AM limit.. SSB units used the same finals stage between AM and SSB modes BUT in AM mode those units WERE reduced to 5W to the input of the finals resulting in the 4W AM max output..

I had a nice Cobra 23 channel base unit that a friend gave me before he passed, he had it "expanded" to 40 channels PLUS some "outside" the band.. Never used the expanded channels but I did check the frequencies with a frequency counter, dead on for the extra CB channels and the others right into 10 mtr ham band :M

I disabled those 10 mtr frequencies before selling the unit after a few years of owning it (just didn't use it)..

The last straw for me was one time was following a friend in vehicles, he was one car length ahead of me.. Could not even here his transmissions due to so many folks stepping on us with overmodulation and linears... We could have yelled out the windows and been able to understand each other better..