Quick shortcut way to see if your amp is running right/clean



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This vid just shows how to do a quick test on an amp (or radio) to see if it is clean or throwing a harmonic, feedback, or ac hum etc without using a scope. If the signal is clean, a wattmeter will show the same watts with a dead key on both Peak and RMS! Yes, even a Bird wattmeter. If the wattmeter shows a difference between peak and average (only on a dead key) then something is wrong with your signal. RF wattmeters look at dead key (Carrier) as DC, and modulated AM RF (Swing or audio) as AC. If you know basic electronics, with DC, Peak and RMS are the same. Hence if your wattmeter is showing different, you are dirty, you have a problem. Best to use a scope though, but not everybody has one of those. That's all I really wanted to show in this video, but if you are interested in whats going on with the Maco in the vid, keep reading.
Still in the process of refurbing a 2nd Maco KW recently I picked up. This one had a base power supply (which I wanted to see/copy badly) and the RF deck. I already had another RF deck, but with a mobile power supply in rough shape and no base power supply. Since I don't do mobile and don't have a DC power supply that big, I was building a base AC power supply from a Phantom 500 chassis. A Phantom normally has 10 or 12 tubes and 3 transformers. D+A amps normally use 1 transformer for every 4 tubes. However since I was going to use this Phantom just to power the Maco KW (11 M-2057 tubes), Everything except the high voltage circuitry was taken out and a 4th transformer was installed. Anyway, the schematics I found on it are not complete (even on CBTricks) so my project stalled. Now with this complete Maco KW, I already reversed engineered it, made my own schematic with pinouts, and after I get out a few more bugs, hopefully it will be ready to rumble and then I will go back and tackle the 2nd one too. I normally start with recapping an amp, but I wanted to reverse engineer it first and see some output before I started changing things around. I got output now, but those original HV caps aren't up to the task. Update video coming soon.
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