Anybody know how to divide a QAM modulated carrier by 2 while keeping the modulation?
I just soldered in the 2.4 GHz VCO, this should result in a 2.4 GHz QAM modulated signal, but it would be nice if I do no need to build a down converter (mixer type).
I think this is not possible?
This is not possible. You need that down-converter.
Just use a sub-harmonic oscillator for a divide by two. With a tetrode,the power goes into a grounded plate (yes,zero volts), and the power out is from grid #1. Power gain might be in the region of -30dB.
WTF ?
I am in no position to call anyone here ficking nuts, but I think this is close. You really should descrivbe the theory of operation of this - um - whatever it is.
A Robertotron ?
Actually he might be able to use some sort of small magnetron to do this I think, but the details are not clear to say the least.
Remember regenerative receivers and the qunching ? There might be something up that path.
Or not. I really do not know. Personally I think it is impossible, but you know alot of things USED TO BE impossible so I will not really say it.
And Robert, if you can get this to work with a tetrode, you think maybe is would work with a dual gate FET ? What were you gong to do with the other grid there ?
Curious. (er now)
OK; i am going to assume that you did not get waylaid by the negative power gain, nor getting power from the grid. That correct terminology was inserted to confuse the masses.
Circuit: input (tuned to fundamental) signal/transformer drives the plate around ground. Cathode, grid #1 configured as a conventional oscillator adjusted to almost oscillation (tuned to 1/2 fundamental, the sub-harmonic) with grid #2 acting as the plate; typical voltage around 40-50V as i remember; oscillation adjustment prolly done here. Been around 50 years since then. Input AM is seen at the output, giving the desired results. Good for NBFM as well. Should be decent for QAM.
A dual gate FET might work; one needs non-linearity as this scheme is the equivalent of a parametric amplifier/oscillator.
On a sunny day (Sun, 09 Nov 2014 13:12:07 -0800) it happened Robert Baer wrote in :
Ah, yes, think I get the idea now. Interesting.
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