This is transistor linear 50-54 MHz power amplifier designed for use with amateur radio. So I have NO idea what part is in this thing. This will allow you to reduce the risk of failure of this product. What could be causing this? Bad relay? Bad coupling caps?Īgain working w/o a schematic has been difficult.Īlso the original receive amp transistor is marked: Most of the powerful dual transistor radios use multiple 2SC2290 transistors to achieve their output. Do not hook up a linear amp if your SWR (standing wave ratio) is bad. Has a factory internal 200w amp for extra power when needed. Also not seeing anywhere near 200w out of it, so I am at a bit of a loss to figure out why this amp isn't working as it should. Hook up the CB antenna, and make sure that the standing wave is correct. When you know which parts of the radio are working properly you can concentrate on suspect stages and. By tracing signals stage-by-stage through your radio you can find the issues that cause it to not play or play poorly. Using a transistor as a switch, similar to a light switch, allows us. A signal tracer is simply an amplifier that can detect audio and RF signals and then play them through its built-in speaker. When you turn on the light switch in your home, you do a little mechanical work with your hands that allows electricity to flow through your light bulbs. They tested OK with both the diode test and resistance test. One of the best features of transistors that enables modern digital electronics is that a transistor can act like a switch. I'm sure this can't be correct.īTW - what is the proper input power to mrf454's? IOW, 3w in to the amp, and 1 1/2w out of the amp when turned off. Texas Star amps are crap but some people are used to that and think they are decent amps. Single Sideband models (SSB) will normally have output of 12 watts, with some models hitting around 18-20 watts after. Once the carrier is modulated, output on the radio may reach 10-12 watts on average with some models hitting around 15-18 watts. The bias circuit was regulated with thermal tracking. A standard CB radio is going to have an AM carrier (also know as deadkey) of around 3 to 4 watts. When the amp is off, I am seeing a 1 1/2 watt carrier loss thru it into the dummy load. If you want a good SSB amp he was building AB biased transistor amps at one point and probably still is. Don't know much at all about amps so bear with me.

Cb radio transistor amp basics