Here's a radio that's not quite 30 years old yet. Won't be long. Serial number says 1995. Long enough for sloppy details to accumulate.
First complaint was no transmit. That turns out to be simple.
After:
Fortunately the driver transistor's collector lead was still long enough to solder securely.
This didn't fix the problem by itself. Yet. Turns out a few tuning slugs had been turned in the transmit section, but that didn't take long to correct. Makes you thing someone was twisting tuning slugs hoping to see the wattmeter magically spring to life.
Now that it transmits, the frequency is over a half channel too low, no matter where I turn the clarifier. Looks sketchy. I always recommend against using electrical tape inside a radio.
Looks just as sketchy without the tape.
Turns out somebody wanted to "unconvert" the clarifier back to stock, with the transmit frequency locked to a trimpot.
Not interested, so I wired it to lock transmit and receiver frequencies together. The orange wire from the ground side of the clarifier control goes where it was already, but it will reach the foil pad where it belongs without the short spliced-in piece.
The hot side of the clarifier control has the white wire with the red stripe. Didn't have any wire that color, so this red wire is spliced onto it, connected to the 8 Volts DC that powers the PLL chip.
Naturally there is more squirrelly stuff on the component side of the pc board as well.
A closeup of D35 explains why the transmit frequency was way off. You have to "unclip" this one to restore factory setup.
I won't be putting D35 back, I want this radio to be useable on sideband.
One last detail remains if you wish to "lock" receive and transmit frequencies together. A resistor on the very front edge of the circuit board gets clipped, R187. Fortunately that was already done. Whoever it was that wanted to restore the stock clarifier wiring didn't have a complete list of the necessary details.
The stranded two-conductor wire connecting the 11.1125 crystal looks suspiciously like the wire used with Expo 100 channel kits for this kind of radio. No evidence of an extra hole in the radio to mount one of those, so who knows? The crystal is more stable soldered directly to the pcb.
Now it's no big deal to set it back on frequency. Just remember to squirt contact/control cleaner into the tiny red trimmer capacitors and spin them until the scratchy noises are gone. No point it setting a trimmer cap if it's noisy and will "jump" out of adjustment on its own.
The older a base radio gets the more personality it acquires. This one turned out just fine.
73
First complaint was no transmit. That turns out to be simple.
After:
Fortunately the driver transistor's collector lead was still long enough to solder securely.
This didn't fix the problem by itself. Yet. Turns out a few tuning slugs had been turned in the transmit section, but that didn't take long to correct. Makes you thing someone was twisting tuning slugs hoping to see the wattmeter magically spring to life.
Now that it transmits, the frequency is over a half channel too low, no matter where I turn the clarifier. Looks sketchy. I always recommend against using electrical tape inside a radio.
Looks just as sketchy without the tape.
Turns out somebody wanted to "unconvert" the clarifier back to stock, with the transmit frequency locked to a trimpot.
Not interested, so I wired it to lock transmit and receiver frequencies together. The orange wire from the ground side of the clarifier control goes where it was already, but it will reach the foil pad where it belongs without the short spliced-in piece.
The hot side of the clarifier control has the white wire with the red stripe. Didn't have any wire that color, so this red wire is spliced onto it, connected to the 8 Volts DC that powers the PLL chip.
Naturally there is more squirrelly stuff on the component side of the pc board as well.
A closeup of D35 explains why the transmit frequency was way off. You have to "unclip" this one to restore factory setup.
I won't be putting D35 back, I want this radio to be useable on sideband.
One last detail remains if you wish to "lock" receive and transmit frequencies together. A resistor on the very front edge of the circuit board gets clipped, R187. Fortunately that was already done. Whoever it was that wanted to restore the stock clarifier wiring didn't have a complete list of the necessary details.
The stranded two-conductor wire connecting the 11.1125 crystal looks suspiciously like the wire used with Expo 100 channel kits for this kind of radio. No evidence of an extra hole in the radio to mount one of those, so who knows? The crystal is more stable soldered directly to the pcb.
Now it's no big deal to set it back on frequency. Just remember to squirt contact/control cleaner into the tiny red trimmer capacitors and spin them until the scratchy noises are gone. No point it setting a trimmer cap if it's noisy and will "jump" out of adjustment on its own.
The older a base radio gets the more personality it acquires. This one turned out just fine.
73
