allan crites wrote:
Kevin, I'm sorry to have to tell you this but I think your calculator
batteries need to be changed.
0 dBM = 0.2236 volts in a 50 Ohm circuit.
+20 dBM is indeed 100 mW and P=EI and inserting 100 mW into the Eq.
for Volts in a 50 Ohm system, E= the sq. rt. of the quantity (.100 x
50) = sq. rt. of 5 = .707 V. or 707 mV. not the 2.24 V. you indicated.
Not sure what planet you are from Allan, but since you admit that 0 dBm
is .2236 Volts, and everyone knows that an increase in power by 10 dB is
the same as multiplying that figure by 10, I'm correct - you are way off.
Even if the rcvr had an input Z of 50 Ohms (without any X component at
the operating freq. which I doubt but let's accept that as so) , the
rcvr input Z at a freq. removed by 6 MHz can hardly be assummed to be
any thing close to 50 Ohms and is more likely to be highly + or -X
therefor not absorbing or accepting any input signal and your
analysis lacks merit.
My statement said power "hitting the input port", I said nothing about
power being accepted or absorbed into the receiver, therefore again -
I'm correct - you are way off.
Let me remind you that, on this particular email list, I (we) strive for
accuracy. I don't just come up with some crap to make things
interesting - I've been 'doing' duplex radio systems since I was 14 -
I'm now 46, so you do the math, correctly this time.
You state my "analysis lacks merit". Unless you have tried the the
experiment I refer to - and have found something different to report,
why don't you try keeping your off base thoughts and inaccurate
calculations/information to yourself. If this seems to come off as a
hot headed warning - you have read this post correctly. (I'm the list
owner (in case you haven't figured that out)). By the way, the GE PLL
exciter has 22 dB less phase noise at 600 kHz from its primary carrier
than does its multiplier counterpart, you can bet it's way more than
that at 6 MHz.
End of thread - everyone please more forward.
Kevin Custer
