Recent content by nomadradio

Wow! They upgraded to surface mount. The pink (violet?) wire is power, the black wire is ground. Leaves you three white wires. One of them is the audio output. The other two probably connect to a pushbutton switch. One white wire is attached near the board's edge near the black wire. I'll guess...

Took a couple of days off. That chip didn't show up in radios I remember from the 70s. Honestly don't recall modding a radio with that one in it. The only schemo I have here at home shows a PLL02A for that radio. I'll see what the Sams shows next time I get to work. 73

I start by unsoldering the center leg of TR43. If you hear no change, the culprit is an early-production TA7222P, probably a "P" and not the later "AP" version. Can't see that ID on the chip until it's removed anyway. If this kills the noise, replacing TR43 is the next thing to try. This...

There's more to it than just the PLL chip's specs alone. What model radio is this? The Sams CB books would mostly provide a guide to the particular divider arithmetic for a specific model. That's always been my starting point for a channel mod. 73

Mission creep? Rampant featuritis? Naw! I'd call it way cool! 73

This is what happens when a popular URL gets abandoned. Gets hijacked to obtain clickthroughs to malware sites. Probably bought it outright when it expired. Tsk. 73

After years of promising myself I'd update our discontinued 1990s PLL synthesizer I finally have a solution I can use. Troy Radio sells a handful of DDS solutions, but one of them is a bona-fide screaming bargain. Their "AM/FM-only" package provides a rotary encoder, nominal 1-inch OLED display...

That's what it is. A quarter Watt fits just fine. 73

The original Centralab product line got sold decades ago to a company called "E-Switch". They boosted the prices through the stratosphere. I need to dust off the wafers we kept after monobanding ham linears for the 11-meter hot-rod crowd. They figured out that it's a weak link in the chain when...

A heat sink on the rubidium box. Probably ought to do that to mine. 73

Hmm. Cobra 21. A 23-channel radio. Not made since about 1976. Cobra 21XLR. Made in 1978 Cobra 21GTL. Made in the early 1980s. Cobra 21 Plus. Late 1980s, a real dog. Cobra 21LTD. 1990s radio. "Cobra 21" is a bit like "Ford Mustang". Doesn't narrow things down all that much. Controls...

The switches I remember had a set of contacts on both sides, operated in parallel. Seems like they held up okay until the SWR got too high. 73

At the school of hard knocks. 73

That's how we test echo boards, pings and roger beeps before installing into a radio. Catching a dud before it's installed saves labor and frustration. That tester has appeared with more than one brand name on it over the years. 73

Bao Feng 2.0? 73