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Not a fault I've seen. Not sure where to look for the PLL's lock detector signal on that one. Might be worth seeing what a 'scope reveals there. Tiny pulses could indicate a PLL on the edge of being unlocked, maybe? Just grasping at straws. 73

Traditional shunt resistor for a grid-current meter is connected from B-minus to ground. But that assumes that the B-minus "floats" and connects to the filament center-tap, maybe through the relay and a zener diode. This model connects the B-minus to ground, more or less. At least the...

Any chance that it thinks it's stuck in transmit? Pretty sure this is what it will do if power is applied with the mike keyed. A circuit fault that keys it for you might do this. Haven't touched a 5010 in decades. Does it have a "TX" indcator on the display like a 2510? 73

Can't tell from the pic which of the three options was used. Connect only the pin 2 wire, only the pin 4 wire or connect both of them to pin 1. Simply wiring up a 4-pin socket to the radio requires one of those three answers to the math problem 5 doesn't equal 4 73

Alignment for a Uniden Washington or Cobra 142 would be a lot closer. 73

Won't get the time to try that before the weekend. Got customer traffic the rest of the week. 73

Static discharge, far as I know. 73

Finally drew it up to match the pics. And the radio. 73

Somebody has modded the mike socket. Just how well they did it, you'll find out. If it says "Uniden" it was built with the 5-pin mike. 73

Bigggest drawback of the rigid metal-body adapters is the leverage. Even a light pull on the mike cord turns into leverage against the nut that holds the socket in the radio. Before long the mike socket is rattling around loose. Just my two cents. 73

The original 4-pin Washington radio with the uPD858 inside bore the brand President. It was made for only one year, 1978. Then the FCC outlawed channel selectors that could be tweaked between detents to produce not-legal binary codes. All radios built `1979 and later with unlocked PLLs like the...

Hmm. Does leave the question of carrier-crystal frequencies up in the air. We're accustomed to poking the center pin of a coax jumper near the carrier oscillator and using a calibrated ham HF radio to eavesrop and use the 1 kHz tone method. If you hear the pitch of the receiver's noise change...

Or you could install our 4-pin mike socket adapter. Only uses pins 1,2 and 3. Pin 4 can be hacked as "phantom" power for a mike with active circuits. Pricey, but it would make the desktop a bit neater...

This the basic design found in the Yaesu FT-101 radio before inflation made them leave it out from the "EE" models. Processing the RF signal is more effective than processing the audio. 73

The older they get, the more expensive it gets to rehab them. I wish I had a name to pass along, but everyone I knew who would take that job has passed on, can't see well enough or hold his hands steady to do that kind of job. No telling how helpful Google would be these days. 73

Drew this up ages ago from a customer's radio while it was here. The chip is a custom part meant to be used in a suburban-home intercom system, with a single Ding on the yellow wire for the front door, a double ding-dong on the brown wire for the back door, and a third noise that I can't...

That's the joke now. The CB is the "backup" radio. Only gets turned on when traffic backs up. Keys the mike asks what's up and gets told he could have gotten off at the previous exit and gone around the backup. If he had the radio turned on before arriving at the parking lot. 73

RTFM part two: The three binary inputs that select one of eight stored frequencies are indeed inverted logic. That means a "zero" is a logic high, or 3.3 Volts. And a binary one is logic low, or ground. The manual doesn't say so explicitly, but it does say that if you don't connect anything to...

Is the driver's Plate Tune control a bit "twitchy"? Does it behave differently on one side of the knob's peak position than it does on the other side of the peak? Next suspect on the list after a grid-bias fault would be a stability issue, especially in an amplifier with a built-in driver stage...

Sure sounds like a failed filter capacitor in the negative grid-bias voltage source. Did all the small electrolytics get replaced along with the big ones? The only rational approach is to replace every, single one, large and small both. 73