Question about radio waves

[RISC777]

"I haven't checked my wobulator lately. (Do you know what one is?)"

I do, now.

"See what happens when I stay up 'till 3:00am? Oh that's nothing, you should see me leaving the Field Day site Sunday morning in a straight jacket! . . . "

Some jackets can be quite comfortable.

 

[RISC777]

"What is velocity modulation and how is it used?"

Accomplishing interchange of power, dc power to rf power. Electrostatic field acceleration and deceleration.
' The amount of kinetic energy in an electron is directly proportional to its velocity. '

edit: Oh, used in microwave tubes.

 

[kb2vxa]

Hi Risc and all,

First things first, no you don't. "Wobulator" is an outdated name for a sweep frequency generator. I tried on a straight jacket once and it's NOT comfortable in the least. Mo hair jackets were a fad, at least for a time Mo was comfotable without all that itchy hair. I never figured out what that stuff was and I hadn't even heard of Mo Collins back then.

Yup, velocity modulation is accomplished in the klystron used in UHF TV transmitters. I have seen smaller versions used in old microwave gear, it is a metal octal based tube with a cap and looks like something out of a shortwave receiver I once had. At the same hamfest I saw some old WW2 Nazi tubes with "Wermacht" stamped on them, neat. The REAL kicker was a case of kinescopes NIB, wish I hadn't spent my money, I would like to own one of the first TV camera tubes.

Edited because mo hair without the jacket would confuse the heck out of you. Around that time there were hippies, they had mo hair then than thier kids have now. Strange, nobody made sick jokes about it, must be a flashback from all that acid. I'll leave you with this thought, mho is the reciprocal of ohm, the unit of conductance. Now they call it seimens which prompted me to update The Sex Life of an Electron after all these years. And you thought a pregnant antenna was a sick joke???

"It's alright ma, I'm only bleeding."
Dylan

 

[RISC777]

Actually, the pregnant antennas had me laughing hard enough to wipe tears away.

edited to Apologize for slightly hi-jacking the thread.

 

[Al42]

"The higher the frequency, the smaller percentage a given bandwidth is."
Isn't that another way of saying;
"The frequency bands are bigger the higher you go so a higher data rate and more occupied bandwidth is allowed.

Not really. Frequency bands are an arbitrary man-made thing. What I said is a mathematical fact - 1 MHz is a smaller part of 5,000 MHZ than of 50 MHz.

After market add-on;
Here's a question for the Geek Squad. If you modulate a 1MHz carrier with a 2Mb/s data stream, what wold be the occupied bandwidth?

Depends on the modulating waveform (a perfect square wave would produce an infinite bandwidth - rise time of zero is infinite frequency), but probably around 20 MHz or so if you were close enough. Close enough to "DC-to-daylight" so as not to matter.