On 8/1/2014 12:22 PM, Rob wrote:
Jerry Stuckle wrote:
On 8/1/2014 8:18 AM, Rob wrote:
Jerry Stuckle wrote:
On 7/30/2014 1:22 AM, Lostgallifreyan wrote:
Jerry Stuckle wrote in news:lr9ohj$33f$1@dont-
email.me:

But the amplifier you're trying to use is meant to feed a receiver
directly, not another antenna. So output is going to be very low (on
the order of microwatts) - much lower than any amplifier which feeds an
antenna.


Small point, but.... Microwatts. Those new legal microstransmitters are said
to be in NANOwatt range output, but allegedly work on the distance scales I'm
interested in. Microwatts should certainly have worked, but despite the crude
test dipole being good (on standard wired reception test anyway), it didn't
work for transmitting even a foot or two with the radio's whip parallel to
the upper part of it. If nanowatts should have, the MAR-6 looks like driving
picowatts, if I'm lucky.


I would suggest you check again. Receivers aren't that sensitive. Most
unlicensed transmitters are in the 100-500 mw range, and have a coverage
of maybe 100 feet. And picowatts aren't even worth discussing.

You were the guy that believed that dBm meant dB over a millivolt,
weren't you? And claimed that you had all that experience in cabling
and signal levels? And thought that digital TV was transmitted at
the same ERP as analog?

I'm getting more and more astonished that you made any working system
and did not just fry the expensive receivers of all your clients!


And I'm more and more astonished that you seem to know my business
better than I do.

I certainly do! Your claims are all hogwash. Either you did not know
your (technical) business when you were in it, or you have forgotten
everything now that you are out of it for decades.


No, you know NOTHING about my job, the people I employ or their
technical expertise. You think EVERYONE IN THE WORLD is as smart as you
are. But here's a clue - the VAST MAJORITY OF THE WORLD is SMARTER THAN
YOU.

You have no idea about what orders of magnitude are involved.
For example: a picowatt is about 8.6uV in 75 ohms. An FM receiver
will give a clear signal on that. Not full quieting, but certainly
receivable.


I know EXACTLY what a picowatt is. And I also know what portable
receivers are capable of. Sure, if you feed a picowatt directly into
the front end of a receiver, a good receiver will hear the signal. But
what field strength do you need at the antenna for a portable FM
receiver to hear that signal? And most of your inexpensive portable
receivers will not hear much of a signal (if at all), even if you do
feed a picowatt directly into the front end (not that you can without
major surgery on the receiver).

Unlicensed transmitters for dedicated frequencies like 433MHz (wireless
headphones and the like) are about 10mW, and for broadcast bands
(e.g. to link an MP3 player to a radio) they are even less. E.g. in
the FM broadcast band the limit in the EU for such a transmitter is 50nW
effective radiated power. That still allows for a 30dB path attennuation
for a usable signal on the receiver.


Sure, but you're also talking a 5Khz deviation (actually about 12Khz
bandwidth). Commercial FM uses 75Khz deviation (typically around 180Khz
bandwidth). A huge difference.

But as you are used to jumbling up your dBm and dBmV values, you have
no idea about that. Your business was probably connecting ready-made
equipment, and selling. But certainly not testing and debugging, that
is clear.


No, i am not used to jumbling them up. You just have no idea what my
industry uses for measurements.

IOW, a typical troll - thinks he knows it all when he knows absolutely
nothing.

--
==================
Remove the "x" from my email address
Jerry, AI0K

==================