The ElectronMans Cave

RF Transistor Testing: Spotting Fake 2SC1969 Finals the Right Way

By AJ York • N5AJY

Counterfeit RF transistors have been a problem for years, and the classic 2SC1969 final is one of the most commonly faked parts on the market. In this article, I’ll walk through a real-world comparison between commonly sold “Mitsubishi” clones and the newer HG 2SC1969 replacements—and why testing matters more than labels.


The Problem with “Too Good to Be True” RF Parts

Like many techs, I’ve purchased 2SC1969 transistors from online marketplaces that were clearly marked as Mitsubishi. They often work—at least at first—which makes the problem harder to spot.

But markings don’t make a transistor genuine. Performance, bias behavior, and internal structure tell the real story.


Initial Bench Testing: What a Tester Can (and Can’t) Tell You

Using a standard transistor tester, both devices appear normal at first glance:

This is where many people stop testing—and that’s the mistake. A basic tester can confirm polarity and junctions, but it does not tell you how the device behaves under RF load.


An Interesting Discovery: Junction Behavior

When testing the HG 2SC1969, something stood out immediately. The tester detected a diode-like junction between internal elements that was not present in the common clone.

That difference alone doesn’t condemn the clone—but it’s an early hint that these parts are not built the same internally.


Real-World Test: Cobra 2000 Final Comparison

Bench tests only go so far. The real test is how a transistor performs in-circuit.

Using a Cobra 2000, I performed a straight swap:

Chinese Clone “2SC1969”

HG 2SC1969

Same radio. Same circuit. Same conditions. The only change was the transistor.


Bias Matters—and Fakes Often Get It Wrong

One of the biggest red flags with counterfeit RF finals is improper bias behavior. If you can’t properly set bias, you’re not working with a correct RF device—no matter what the label says.

In this case, the clone would transmit power but refused to behave correctly during bias adjustment. The HG device behaved exactly as expected.


Why This Matters for Repairs

Installing counterfeit finals can lead to:

You end up chasing problems that aren’t really there—all because the part itself is wrong.


Final Verdict

Not all replacement RF transistors are created equal. While some clones may “work,” they don’t perform like the real thing—and that matters in RF stages.

If you’re repairing radios that originally used the 2SC1969, the HG 2SC1969 is currently the closest true replacement I’ve tested.

Spend a few extra dollars. Save yourself hours of troubleshooting.


Related Reading

As always, this is real-world testing—not theory, not hype, and no affiliations. If you have questions, I’m happy to help.