His first truck was a cab over engine (COE, picture on left) with extra strength rear springs (for a more comfortable ride with heavy loads), but he normally had light loads, so the ride was extra harsh.
His next tractor was a 225" wheel base, air ride equipped Freightliner (euphemistically called a Freightshaker in the biz) with a conventional layout (picture on right) , known as a "coffin nose" or "hood", for obvious reasons. This tractor featured a much more comfortable ride.
A " linear" is an illegal power booster for a "CB" radio.
You can legally transmit with up to 4 watts of power.
Most drivers have their radios "peaked and tuned", that is, hot rodded to put out about 20 watts, to increase the effective range of transmission.
Back when, many drivers ran 100, 500, even 1,000 watt linear boosters that would shred your radio if they "keyed up" (transmitted) within twenty miles of you.
These amps also emitted so much spurious RF (radio frequency) energy, that they would heat up metal parts in the cab.
The joke was that drivers sitting right over one of these were surely microwaving their family jewels and rendering themselves sterile!
Nobody uses these anymore for obvious reasons, plus the FCC has gotten much more skilled at locating these mobile pirate radio stations! Big fines!
As an aside, modern trucks are more comfy than a Cadillac. The driver sits in a seat with air suspension to isolate him from the cab, which sits on an air suspension to isolate it from the movement of the frame, which sits on an air suspension to isolate it from the road surface. Think "magic carpet"!
Advanced aerodynamics reduce wind buffeting, set-back front axles reduce turning radius and effort, 600 hp engines with almost 2,000 lbs/ft of torque pull endlessly. Now the majority of new tractors are equipped with 10 speed automatic transmissions, because companies have a hard time finding drivers that know how to "row their own" (drive a stick).
The trucking industry has advanced, technologically, more in the last 10 years than in the previous 100.
Sorry, I'll let myself out now.
Leaving quietly.
No, please, don't get up.