ARE ALL BASE CB AMPS SPLATTER BOXES?

[Sonar]

The Heading says it all.
Is dirty in dirty out true?
Is the fact that (most all) 11 amplifiers lack any type of filtering make them splatter boxes?
If 1 is driving an amplifier with and unmodified non golden screwdrivered transceiver with a an excellent oscope waveform is it possible for that amplifier not cause splatter? Or is it a splatter box no matter how clean of an (audio) signal you put through it? Are tube amplifiers more likely to be dirtier then transistorized ones, or vice a versa (if they are indeed splatter boxes?)

 

[groundwire]

Amplifiers dont splatter, transmitters do. Amplifiers just amplify. What goes in is what comes out, amplified. amps can add distortion but thats a different matter

 

[543_Dallas]

Amplifiers absolutely do cause splatter. Splatter is known as IMD. This is caused my non linearity in the amplifier. Filters will not help. The amplifier must be properly built biased and not driven into gain compression. The builder and the operator have to do their part. You can filter the hell out of a class C amp and it's still going to splatter. If you start with a dirty transmitter the non linear amp makes it even worse.

Filters are for harmonic suppression. Harmonics are not splatter. Harmonics are found on multiples of the fundamental frequency. People on the next channel are not hearing harmonics. Transistor amplifiers should absolutely have filtering because they are so broad banded and will amplify whatever you put into them. Tube amps use a pi network to match the high impedance of the tube to the 50 ohm antenna system. This network provides some filtering. The tuned input circuit also helps some. A lot of ham amps use a pi L and have even more harmonic suppression.

All CB amps are not splatter boxes but if the operator drives the hell out of it it sure will be.

 

[nomadradio]

Twenty years ago I removed the AMC trimpot from my Saturn Turbo and wired a front-panel control in its place. The "bench" amplifier was a converted Dentron MLA with two 3CX800 tubes. With the AMC wide open, it would show over 2000 Watt peaks. Had analog cable TV at the time. Found that I could put that much power on the beam and really tear up the TV across the room. Also found a 'sweet' spot on the AMC control. Turned the modulation percentage down until the TV cleared up. A quick check on the 'scope showed about 90% modulation. This reduced the PEP meter reading to around 1500 or so. At the time, FCC advice on interference was that if the devices in your own house weren't being torn up, you were off the hook.

Found I could talk with this setup, no problems with TV interference. Other stations would ask if I was barefoot. Had one stock answer "Who are you kdding?" That seemed sufficient to change the subject. More than once heard locals arguing over whether I was really barefoot or not. One would swear that I must be. He had tuned up one and down one channel and couldn't hear me "scratching" him at all. Couldn't imagine I was amplified if I didn't bleed at least one channel. Another one argued that I had to be amplified. Nobody barefoot had ever covered up his annoying neighbor a half-mile away.

Most of the time it's not the wattage, it's the overmodulation that causes interference trouble. Amplifiers only make it worse.

73

 

[Justme]

See above 543_Dallas, answer.
One reason even with a good filtered radio i always watch the ALC action.
When it starts to react i stop driving it further, see it as an emergency break.
really, that last few watts won't make the difference and some of those watts are harmonics anyway not adding to your signal strength but causing possible out of band problems.
Reason i use the Heathkit SB-1000 filtered input filtered output and don't overdrive it.
Needs just 50 watts clean signal to make 700 watts out
on the new 3.500 ZG.
Living on the edge of a city i rather don't cause interference with neighbours or farther out.
You would be surprised how far harmonics reach...

Even class A/B amps can cause harmonics when overdriven, or used within specs.
The only amp that puts out what is put in is a class A amp, if used withing specs like my FT2000-D 200 watt radio running 75 watts class A.

 

[Staybolt]

Twenty years ago I removed the AMC trimpot from my Saturn Turbo and wired a front-panel control in its place. The "bench" amplifier was a converted Dentron MLA with two 3CX800 tubes. With the AMC wide open, it would show over 2000 Watt peaks. Had analog cable TV at the time. Found that I could put that much power on the beam and really tear up the TV across the room. Also found a 'sweet' spot on the AMC control. Turned the modulation percentage down until the TV cleared up. A quick check on the 'scope showed about 90% modulation. This reduced the PEP meter reading to around 1500 or so. At the time, FCC advice on interference was that if the devices in your own house weren't being torn up, you were off the hook.

Found I could talk with this setup, no problems with TV interference. Other stations would ask if I was barefoot. Had one stock answer "Who are you kdding?" That seemed sufficient to change the subject. More than once heard locals arguing over whether I was really barefoot or not. One would swear that I must be. He had tuned up one and down one channel and couldn't hear me "scratching" him at all. Couldn't imagine I was amplified if I didn't bleed at least one channel. Another one argued that I had to be amplified. Nobody barefoot had ever covered up his annoying neighbor a half-mile away.

Most of the time it's not the wattage, it's the overmodulation that causes interference trouble. Amplifiers only make it worse.

73

Neigbor across the street would blame me for tearing up his tv even with a 4 watt stock cb. I told him I dont tear up anything in the house. He didn't believe me so one day I made a video on my phone showing him nothing was interfered with and showed him my 4 watt 40 ch cobra base. I haven't heard a thing from him since...

 

[M0GVZ]

Neigbor across the street would blame me for tearing up his tv even with a 4 watt stock cb.

It's perfectly feasible to do that with 4W, most often down to the lack of a RF ground and the coax radiating thanks to common mode RFI. It used to be a real issue here in the UK where over the air TV was the only thing available.