Hi Vic, there are several things that might explain what you see, and very likely it's a combination of several. The dummy load might not be exactly 50 ohm with zero reactance. Most are pretty good,
Jim, AND -- there's another point that virtually EVERYONE who has commented in this thread seem ignorant of. ANY distortion mechanism produces BOTH harmonics and INTERMOD. Good point to keep in mind.
Jim, But is it in an RF amplifier? Really? Spend a bit of time on any ham band with a spectrum analyzer that has good frequency resolution and you'll learn in the first 30 minutes that this is true.
Alex, I think the ARF15XX line has 300 V devices.at the kW level involved, the output impedance is disgustingly close to 50 ohms. Do you mean to say "delightfully close"? I would see it that way - if
Gary, your post pretty much condenses this matter. I will just comment on a few of the points: Inter modulation is just what the term implies. Two or more signals modulate each other in the signal pa
Cathy, I sent you a direct reply yesterday, but your e-mail server bounced it back, stating that my server's IP is banned! Do you happen to have some alternative e-mail address where I could send it
I also shudder somewhat when I see a Morse code transmission referred to as "continuous wave". Only the radio industry does. The semiconductor industry doesn't. When you look into the datasheet of an
Hi Jim, and all, When you see an SDR receiver selling for a few hundred bucks, it's pretty simple to add a low power transmitter. So adding a high gain amplifier makes for a cheap SDR radio capable o
Hi Peter, A friend of mine, ex Telefunken design engineer, already built a class E amp around 2x8 cheap SIHP10N40D transistors at less then 1 Euro each. With 15W of drive output is 1200W. I just had
Chris, I know that Manfred and others on this list have advanced thermodynamics knowledge Well, mine isn't really advanced, it's just somewhat better than that of most hams. I still need to use onlin
Bill, I have experienced several such cases of fellow hams blowing crud all over a band, and "not hearing" those who report the problem. But most of the offenders I have heard are operating factory-m
Jim, USING ALC to control drive level for a power amplifier is a CAUSE of splatter and clicks. ALC should NEVER be used to set drive level. How do you do it, then? I would say that when transmitting
Jim, You are confusing speech processing, which is generally done at base band (that is, on the audio signal before it is applied as modulation), with ALC, which is control feedback between an RF amp
Cathy, Jim, and all, I have seen many, many online posts asking for an all-mode VHF/UHF rig that doesn't include HF. These used to be available, but have disappeared. Such rigs appeared on the market
Cathy, For weak-signal usage, you want low noise figure and high sensitivity, but you really don't care about dynamic range. You are unlikely to have a strong signal next door to desense your rig. Th
Joe, With amps or VHF/UHF radio I have always wanted to see a weather proof black box to mount at the antenna and then a control panel/power supply for the shack. It's not really convenient to place
Gerald, Scott, The satellite is the moon of course. With current and free WSJT software there is no need for the gigantic antennas that have been used in the past. I have used WSJT, and at first it w
Steve, and all, I was nearly killed at age 15. This seems to be a pretty universal initiation rite for homebrewers. I used to be very careful and cautious even when a youngster, but still couldn't av
Hi Cathy, Jim, and all, I agree that a part of the higher dissipation is caused by higher idle current, multiplied by higher plate voltage. But I think that you are wrong in a few points here, Jim, a
Bill, Today those of us look back at what we did and would not want our own children do the same. And I think that this is a mistake. Teh current generation of children, in many parts of the world, i