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Carlbuilt 400HD vs C400 vs CM400
- Thread starter TimmyTheTorch
- Start date
His bias circuit is crap. Schottky clamping diode/resistorsThat bias is just resistor providing bias voltage or temperature compensated bias circuit as it should be done?
Mike
The only builder I have ever saw do this was Peakaboo in the Joker amplifiers. He came up with and designed his own regulated AB bias scheme. He would even grind off component part numbers and values so no one would try to copy it. Best amp I ever owned.That bias is just resistor providing bias voltage or temperature compensated bias circuit as it should be done?
Mike
He is selling those boards now. I bought four of them due to no time to make the boards from scratch myself. Each board serves 2 transistors. He uses the TIP31 setup. I dont know of any fulltime builders using that bias setup yet, the ones that do bias is just the diode/cap/resistor deal as far as I know. I guess thats better then no bias. I think Shockwave turned me to Him if I am not mistaken. Rob S also built like that too.
Ahem
...
I did it as well. I even had a thread here showing the schematic and everything but it's lost to time. I basically copied a Kenwood bias schematic.
The bias he uses is class B schottky diodes and resistors. Garbage amps.
It's a CB amp, and in that sense they're all garbage amps, however it's still better than some of the class C stuff that seems built to include the least amount of parts and still make RF.
Cb amps are not Henry or Metron built quality.....
73
Jeff
Not from what I have seen. Horrible construction, the cheapest parts possible and oscillates like a kazoo, when driven below recommended limits. Spurs-a-plenty. But, he says, his amps don't spur. Must be some kind of voodoo in here that makes his junk special.
This is on my bench today
Attachments
have you seen fan failure or overheating issues with Carl's boxes? c80 and hd200 models with lots of talk time on ssb. with 7w PEP per 2879 and 5w per 2290, these boxes have never got above 100° in a 70° environment, or a poor audio report on ssb. kept clean, smoke free, and with a low standing wave.
original poster: i recommend the variable power option. 1 of the boxes i have does NOT like the high position on the output power switch (200hd). having a panel meter showing draw on the power supply and a decent swr meter told me something was set to go way too hot. i stay away from what he recommends for drive input or power output.