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Do you mean the value of the old part that was removed? The small ones seem to deteriorate sooner than the big ones. 73

As popular CB radios become older they get senile. In a way. Aluminum electrolytic capacitors have a finite life span. And a radio with dozens of them inside can develop a whole spectrum of quirks and outright failures as they fail. Problem is, the age alone is not the only factor. Mileage...

Here's a fault we have seen in more than one newer Connex radio. This one is a CX46 with the amplifier under it. The problem occurs when the transmit audio gets "enhanced", or the modulation boosted in any way. The transmit audio will squeal no matter where the mike gain is turned. Turn it all...

Twenty years ago or so I posted pics showing how to "lock" the clarifier on a RatShack TRC-457 base CB. Has the same pc board as a whole list of 1978 radios, but the mobile version sold by Cobra is different. The control wires on the base station connect to the solder side of the pc board. The...

That's what I need to do. Come up with a popular product that sells out in less than a year, but with half the stock held back. Then come back two years later when the price has tripled or more, and cash in with the remaining half of the original stock. If only Eric had a few dozen cases of...

Found this listing for the volume/squelch/power control used in millions of mobile radios. Same one used as echo volume/speed...

Yeah. People want what they want. 73

Nope. FCC wouldn't permit it. The 8734 is the only factory-installed part. It's a partly-crippled 8719. An Expo-100 style crystal kit will work with the 8734. The advantage is that the channels are all in sequential order above 40 and below 1. Modding the PLL chip inputs throws the added...

That radio dates from the mid-1980s. If your buddy had a 1985 Ford Tempo that won't start, there's a good chance it would need more than just one little thing to make it a daily driver again. 40 years takes its toll, even if the mileage is low. Some time around the 40-year mark, you can count...

The current drain of the radio can't be measured easily using the internal power supply. But putting your meter on the 10-Amp DC hookup and inserting it into the positive wire of an external DC supply might be informative. If the radio is drawing excess current, that alone might be causing the...

It's almost never the transformer. That component tends to be a go/no-go proposition. A "partial" fault almost never happens. The unregulated voltage you measured sounds about right. The voltage regulator is failing to hold the output steady. Question is why? An oscilloscope is a handy tool for...

The whole folklore of "known" issues is mostly relevant the first 20 years of the radio's life. When it gets to be closer to 50 years, it's best to expect multiple faults. A quick "known" fix for troubles in a radio that old is probably a vain wish. When we replace all 50 electrolytic caps in...

Schematic is in the CB Tricks collection. The mike only uses ten of the twelve pins. At least what's inside the factory mike is all pretty mundane. 73

As Roseanne Rosannadanna would say, "It's always somethin'". A friend generously offered to powder coat a DX300 top cover. Seems appropriate for an amplifier with an asking price around a kilobuck. Just one problem The powder softens and sags when heated. It filled the upper right corner. Made...

Got it! Gonna use it on the next one. Just can't bring myself to tear this one down that far again. 73

For sideband stay away from built-in drivers. Stick with as many transistors in one stage as you can afford and drive them directly from the radio. And yeah, you need bias. Sideband audio quality is unforgiving about amplifier drive level. Staying around 2/3 throttle compared to an amplifier's...

For a long time FM broadcast stations used a half-wave dipole shaped into a circle. Just how equal the pattern was around the azimuth I don't know, but to increase ERP they were stacked one above the other. Don't remember seeing more than four of them stacked that way. If you're looking for an...

Is this the one with six pins? 73

I thought it took a toggle switch to make the connection missing from the sequence in the channel selector. 73

Start 'em young. Told my daughters more than once they could help with a brake job or ride the bus all week. 73