White Tornado 225 Plus

[SMILEX2692002]

I have one. It has 2 2sc2879's HG brand in it.
I'm seeing 150 watts pep on AM and SSB with a HR2510.
Its drawing around 12-15 amps from my power supply.

I notice the low power level is no different than the high power level setting.
The medium just limits the power back a few watts on the AM carrier.

I believe this amplifier had mrf 455's from the factory.

I wonder if the circuit board is only configured to allow power levels of what the factory Mrf 455's would produce?

Since I have 2× 2879's I expected more output power?

 

[nomadradio]

The one I remember with this name had a pair of 2SC2290 in it. That transistor was a bit cheaper than the 2879 25 years ago.

Sounds like the impedance-matching setup in the amplifier is optimized for the smaller transistor. If you have a look at the Texas Star schematics on CB Tricks, you'll see that the component values and transformer windings are not the same for both transistor types.

Don't have a revised setup on file to optimize that model for the larger transistors. Tweaking the capacitor values and transformer windings is a bit like shooting in the dark unless you have a similar amplifier with a working setup to copy. Biggest hazard is making it unstable. If it oscillates and "runs away" that can pop the RF transistors.

If there was a chance of doubling the power, that might come close to being worth the expense and trouble. On average that would boost the S-meter reading on the other end by one S-meter number or less.

Tweaking might get you half-again the wattage above what you see now. Probably no more than that. Certainly not double.

The marginal increase of around 50% you might get from heavy-duty tweaking will get you an even smaller S-meter boost at the other end.

If you're just in love with a higher wattmeter reading, go for it. Worst you can do is blow it up, or maybe also the radio's final.

But the payoff won't be an increase in transmit range that's enough to see.

All a matter of what your objectives are.

73