Here's a CB accessory that was a plague on the land 30 years or so ago. The Workman RF Preamp module.
Was a small circuit board with four wires, enclosed in a hunk of heat-shrink tubing.
At least they didn't encapsulate it in black goop.
Once installed, there is no relay to bypass it. Always on, can't be turned off. Not if you want to hear anything at all.
Pretty simple circuit. One transistor, one diode, three capacitors and four resistors.
Solder side looks kinda simple.
The schematic isn't too complicated, either.
The way the MPSH10 transistor is turned around on the board suggests it was designed for a transistor with a different pinout. No idea what type, but a long list of parts will work in this circuit.
Back in the 90s there was a guy who worked the third shift CB repair in a chrome shop a hundred miles east of here. No joke, third-shift CB repair. He lacked a few vital skills, including receiver alignment. His answer to any customer's report of "poor receive" was to install one of these. Perked it right up.
Until anyone within five miles keyed up on another channel.
Okay, maybe it didn't overload the radio quite to that extent, but the customer was happier with it removed, once he had heard the before-and-after. Had a sack full of these decades ago, but this straggler just turned up while excavating, er, "housekeeping" last week.
Pretty sure they stopped selling this item a while back, but here's more than you ever wanted to know about the Workman RF Preamp.
73
Was a small circuit board with four wires, enclosed in a hunk of heat-shrink tubing.
At least they didn't encapsulate it in black goop.
Once installed, there is no relay to bypass it. Always on, can't be turned off. Not if you want to hear anything at all.
Pretty simple circuit. One transistor, one diode, three capacitors and four resistors.
Solder side looks kinda simple.
The schematic isn't too complicated, either.
The way the MPSH10 transistor is turned around on the board suggests it was designed for a transistor with a different pinout. No idea what type, but a long list of parts will work in this circuit.
Back in the 90s there was a guy who worked the third shift CB repair in a chrome shop a hundred miles east of here. No joke, third-shift CB repair. He lacked a few vital skills, including receiver alignment. His answer to any customer's report of "poor receive" was to install one of these. Perked it right up.
Until anyone within five miles keyed up on another channel.
Okay, maybe it didn't overload the radio quite to that extent, but the customer was happier with it removed, once he had heard the before-and-after. Had a sack full of these decades ago, but this straggler just turned up while excavating, er, "housekeeping" last week.
Pretty sure they stopped selling this item a while back, but here's more than you ever wanted to know about the Workman RF Preamp.
73
