Indoor FM boost with no cables?
 

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.

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

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

Indoor FM boost with no cables?
 

Jerry Stuckle wrote in news:lraskh$gup$1@dont-
email.me:

Most
unlicensed transmitters are in the 100-500 mw range, and have a coverage
of maybe 100 feet.

That sounds right. I thought nanowatts seemed a bit small a claim. I probably
need about 10mW based on what you said there. (I think it was Wikipedia's
article that stated the nanowatts, but as so often happens, there was no
mention of the antenna and actual radiated power, no hint of what efficiency
(or lack of) resulted.

I won't retry for now. Messing around with a direct wired link to the
external aerial is more fun for a while. ETM on a PL-390 is as fun as many
people have said it is...


And picowatts aren't even worth discussing.


I should never have mentioned them. :)

Indoor FM boost with no cables?
 

Jerry Stuckle wrote in news:lras98$ebf$1@dont-
email.me:

As for determining whether it is oscillating or not - I wouldn't trust
anything short of a good spectrum analyzer. The signal could be
anywhere (and changing frequency). A spectrum analyzer will still show
it; a receiver won't necessarily.


No clues at all? I remember when I first set up that little MAR-6 based
preamp, it had some nasty side effects on the sound till I added a springy
ciopper alloy strip to each side on the underside of the board so it bit
gently into the aluminium case when I slid it in to it, finally curing the
local RF oscillations it had before I solved this. I was wondering if similar
audible sounds might be heard as a guide to other, larger scales of local
feedback and oscillation.

Indoor FM boost with no cables?
 

On 7/30/2014 5:00 PM, Lostgallifreyan wrote:
Jerry Stuckle wrote in news:lras98$ebf$1@dont-
email.me:

As for determining whether it is oscillating or not - I wouldn't trust
anything short of a good spectrum analyzer. The signal could be
anywhere (and changing frequency). A spectrum analyzer will still show
it; a receiver won't necessarily.


No clues at all? I remember when I first set up that little MAR-6 based
preamp, it had some nasty side effects on the sound till I added a springy
ciopper alloy strip to each side on the underside of the board so it bit
gently into the aluminium case when I slid it in to it, finally curing the
local RF oscillations it had before I solved this. I was wondering if similar
audible sounds might be heard as a guide to other, larger scales of local
feedback and oscillation.


Not necessarily. Even if there were physical vibrations, they may be
out of the audible range. But even vibrations are not common. You were
lucky you could hear it.

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

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

Indoor FM boost with no cables?
 

amdx wrote in :

Anyway, keep plugging away, as I listen to WABC in New York on my
internet radio, driving my FM transmitter that I receive on a portable
radio I carry around while doing my morning routine, part of which
is writing a compound sentence while in Florida. :-)


Sound a bit like the kind of fun I have with serial links (on smaller
scales). I'll give it a rest for now but I will retry eventually, I like
exploring this stuff. (And others, like coding, which is a rival for my time
right now..) Soon to merge the two demands in a bit of code to make a Psion
Organiser XP control the AR-3000. Lot of fun to be had there, I think.

Indoor FM boost with no cables?
 

Jerry Stuckle wrote in news:lrbmkt$ohq$1@dont-
email.me:

Not necessarily. Even if there were physical vibrations, they may be
out of the audible range. But even vibrations are not common. You were
lucky you could hear it.


Well, it was like a flanger having a psychedilc fit. :) Hard to ignore!
Fortunately easy to cure. I imagine that many other sources of wild RF
oscillation might affect the sound like that.

Indoor FM boost with no cables?
 

On 7/30/2014 5:08 PM, Lostgallifreyan wrote:
Jerry Stuckle wrote in news:lrbmkt$ohq$1@dont-
email.me:

Not necessarily. Even if there were physical vibrations, they may be
out of the audible range. But even vibrations are not common. You were
lucky you could hear it.


Well, it was like a flanger having a psychedilc fit. :) Hard to ignore!
Fortunately easy to cure. I imagine that many other sources of wild RF
oscillation might affect the sound like that.


Not really. To affect the sound, you need something which will respond
to the RF in a physical vibration manner (i.e. magnetic), and the signal
must be in the audio spectrum.

Neither is very likely.

--
==================
Remove the "x" from my email address
Jerry Stuckle

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

Indoor FM boost with no cables?
 

Jerry Stuckle wrote in news:lrcavl$dok$2@dont-
email.me:

On 7/30/2014 5:08 PM, Lostgallifreyan wrote:
Jerry Stuckle wrote in news:lrbmkt$ohq$1@dont-
email.me:

Not necessarily. Even if there were physical vibrations, they may be
out of the audible range. But even vibrations are not common. You were
lucky you could hear it.


Well, it was like a flanger having a psychedilc fit. :) Hard to ignore!
Fortunately easy to cure. I imagine that many other sources of wild RF
oscillation might affect the sound like that.


Not really. To affect the sound, you need something which will respond
to the RF in a physical vibration manner (i.e. magnetic), and the signal
must be in the audio spectrum.

Neither is very likely.


To produce audio from RF directly all that is needed is for the difference (a
beat frequency) to fall within the audio pass band of the equipment. A wildly
varying frequency of oscillation could make a sweep of audio pitch. Timbre or
variability of effect might give plenty of clues as to cause. That's what led
me to find and fix the original oscillations in the dodgy ground plane
connection in the preamp casing. If it can happen this way on one (tiny)
scale, I see no general reason why it could not happen on the larger scale
with feedback between antennas a hundred feet apart. Whether I can use it
diagnostically is questionable, but I think it can exist. Given the number of
frequencies picked up by the antenna, I find it hard to beleive that NO stray
feedback oscillation would differ from any one of them by a value that puts
it in the audio band. I'm fairly sure I'd hear something, especially if
choosing a clean audio signal over which it woudl easily show up.

Indoor FM boost with no cables?
 

On 7/31/2014 3:36 AM, Lostgallifreyan wrote:
Jerry Stuckle wrote in news:lrcavl$dok$2@dont-
email.me:

On 7/30/2014 5:08 PM, Lostgallifreyan wrote:
Jerry Stuckle wrote in news:lrbmkt$ohq$1@dont-
email.me:

Not necessarily. Even if there were physical vibrations, they may be
out of the audible range. But even vibrations are not common. You were
lucky you could hear it.


Well, it was like a flanger having a psychedilc fit. :) Hard to ignore!
Fortunately easy to cure. I imagine that many other sources of wild RF
oscillation might affect the sound like that.


Not really. To affect the sound, you need something which will respond
to the RF in a physical vibration manner (i.e. magnetic), and the signal
must be in the audio spectrum.

Neither is very likely.


To produce audio from RF directly all that is needed is for the difference (a
beat frequency) to fall within the audio pass band of the equipment. A wildly
varying frequency of oscillation could make a sweep of audio pitch. Timbre or
variability of effect might give plenty of clues as to cause. That's what led
me to find and fix the original oscillations in the dodgy ground plane
connection in the preamp casing. If it can happen this way on one (tiny)
scale, I see no general reason why it could not happen on the larger scale
with feedback between antennas a hundred feet apart. Whether I can use it
diagnostically is questionable, but I think it can exist. Given the number of
frequencies picked up by the antenna, I find it hard to beleive that NO stray
feedback oscillation would differ from any one of them by a value that puts
it in the audio band. I'm fairly sure I'd hear something, especially if
choosing a clean audio signal over which it woudl easily show up.


Yes, I know how it works - I've held both amateur and commercial
licenses for well over 40 years and worked on almost everything from $40
CB sets to multimillion dollar mainframe computers. I've even done some
design in my free time. I suggest you not try to teach those who know
more than you your "facts".

The facts a to have the beat frequency, you need two signals within
15kHz or so of each other. Those signals must be mixed, which means at
least one must be non-linear. This will give you a beat frequency in
the audio spectrum.

Once you have this, you need something to generate a strong enough
magnetic field in the audio frequency range to act as a driver, and
something close enough and made of a magnetic material to vibrate.

I've seen a fair number of spurious emissions over the years (mostly
from VHF/UHF radios). Every one of them has been RF, and none of them
have created audio oscillations.

A few months ago we even had a case right here where a VHF radio in a
county bus had a spur on the input to the local 2 meter ham repeater.
Once again, no indication in the bus this was occurring. The county
found out about it only after the hams contacted them.

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

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

Indoor FM boost with no cables?
 

On 07/26/2014 09:24 PM, David Platt wrote:

A few years ago I helped chase down a noise source which was wandering
randomly through the 2-meter repeater input sub-band, and causing
prolonged noisy squelch tails on the ends of transmissions on several
different repeaters in the Silicon Valley area....

Reminds me. Some years back I had the duty of fox-hunting a noise
source inside Great Mall of the Bay Area that was throwing noise on
Milpitas PD's receivers. I wandered around the back doors in the south
core with a PD handheld and a scanner. Turns out a Muzak machine's
power supply was doing it. They sent a replacement and the problem was
gone.

Once there was a laundromat in Redwood City whose TV was spewing junk
around 154 MHz, out the antenna port, jamming Fire channels. I don't
recall how that was resolved, whether an amp was installed isolating the
antenna, or they just got the place a new TV.

Indoor FM boost with no cables?
 

On 7/31/2014 10:07 AM, Eric Weaver wrote:
On 07/26/2014 09:24 PM, David Platt wrote:

A few years ago I helped chase down a noise source which was wandering
randomly through the 2-meter repeater input sub-band, and causing
prolonged noisy squelch tails on the ends of transmissions on several
different repeaters in the Silicon Valley area....

Reminds me. Some years back I had the duty of fox-hunting a noise
source inside Great Mall of the Bay Area that was throwing noise on
Milpitas PD's receivers. I wandered around the back doors in the south
core with a PD handheld and a scanner. Turns out a Muzak machine's
power supply was doing it. They sent a replacement and the problem was
gone.

Once there was a laundromat in Redwood City whose TV was spewing junk
around 154 MHz, out the antenna port, jamming Fire channels. I don't
recall how that was resolved, whether an amp was installed isolating the
antenna, or they just got the place a new TV.




And of course there's the now infamous hair salon in San Antonio, Tx,
with the fluorescent light ballasts that caused problems to AT&T Cell
phone network (and it seems this is not the only business with this
problem).

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

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

Indoor FM boost with no cables?
 

Jerry Stuckle wrote in news:lrdc2v$b15$1@dont-
email.me:

The facts a to have the beat frequency, you need two signals within
15kHz or so of each other. Those signals must be mixed, which means at
least one must be non-linear. This will give you a beat frequency in
the audio spectrum.


Ok, that nonlinear bit makes sense. If the signals do not do that then I'd
have nothing to detect the way I heard it. When I said audio I didn't mean
direct emission from something driven by strong RF. I was thinking it might
be heard from a weak signal added to the output audio signal, as happened
with that preamp's casing before I improved its connection to the PCB's
ground plane. The sound was a kind of whistling squeal, almost white-noise at
times. I imagined that feedbacking antennas might also produce this, and
that's the core of my question, whether or not this is true, or useful even
if it is.

By the way, I'm not trying to teach you anything. I know you know these
things or I'd not be here asking stuff. I was just stating what I know to try
to get to the bottom of this, and so you had some basis for pitching a reply
based on what you have reason to think I might understand.

Indoor FM boost with no cables?
 

On 7/31/2014 3:39 PM, Lostgallifreyan wrote:
Jerry Stuckle wrote in news:lrdc2v$b15$1@dont-
email.me:

The facts a to have the beat frequency, you need two signals within
15kHz or so of each other. Those signals must be mixed, which means at
least one must be non-linear. This will give you a beat frequency in
the audio spectrum.


Ok, that nonlinear bit makes sense. If the signals do not do that then I'd
have nothing to detect the way I heard it. When I said audio I didn't mean
direct emission from something driven by strong RF. I was thinking it might
be heard from a weak signal added to the output audio signal, as happened
with that preamp's casing before I improved its connection to the PCB's
ground plane. The sound was a kind of whistling squeal, almost white-noise at
times. I imagined that feedbacking antennas might also produce this, and
that's the core of my question, whether or not this is true, or useful even
if it is.

By the way, I'm not trying to teach you anything. I know you know these
things or I'd not be here asking stuff. I was just stating what I know to try
to get to the bottom of this, and so you had some basis for pitching a reply
based on what you have reason to think I might understand.


Even if it were a weak signal added to the audio output, chances are you
wouldn't hear it. As I said before - you were very lucky to hear the
squeal before; very few spurious radiations will have any audio component.

And BTW - your problem with the ground plane was probably corrosion in
the connection, causing the RF to be rectified. But even then,
generally it will not be in the audible frequency range.

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

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

Indoor FM boost with no cables?
 

Jerry Stuckle wrote in news:lre73e$jps$1@dont-
email.me:

Even if it were a weak signal added to the audio output, chances are you
wouldn't hear it. As I said before - you were very lucky to hear the
squeal before; very few spurious radiations will have any audio component.

And BTW - your problem with the ground plane was probably corrosion in
the connection, causing the RF to be rectified. But even then,
generally it will not be in the audible frequency range.


Agreed, even the thin oxide layer on the aluminium when new was enough
corrosion. Also, not enough points of contact around the edges of the board
before I fixed it.

About 'lucky', maybe. :) The rason I brought it up was because the sound WAS
so white-noise like. It seemed to imply a scatter so broad that a careful ear
might detect a far lesser version of the effect.

Indoor FM boost with no cables?
 

On Thu, 31 Jul 2014 10:19:38 -0400, Jerry Stuckle
wrote:

And of course there's the now infamous hair salon in San Antonio, Tx,
with the fluorescent light ballasts that caused problems to AT&T Cell
phone network (and it seems this is not the only business with this
problem).

The hair salon refused to do anything about it so they got a letter
from the FCC.
http://www.commlawblog.com/2013/10/articles/enforcement-activities-fines-f/bulbs-behind-bars-ii-fcc-goes-after-hair-salon-lighting-fixture/
Seems to be a common problem. Here's one in Smog Angeles:
http://www.pcworld.com/article/2095940/la-buildings-lights-interfere-with-cellular-network-fcc-says.html
My guess(tm) is electronic ballasts.

My favorite was GPS interference from TV amplifiers:
http://gpsworld.com/the-hunt-rfi/
I was not involved in either the cause or solution.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Indoor FM boost with no cables?
 

On Thu, 31 Jul 2014 08:16:29 -0400, Jerry Stuckle
wrote:

Yes, I know how it works - I've held both amateur and commercial
licenses for well over 40 years and worked on almost everything from $40
CB sets to multimillion dollar mainframe computers.

Well let's see... I got my novice license when I was 15, so that means
I've had a ham license (various call signs) for 51 years. My FCC
First Class and now GROL for about 46 years.

I've even done some design in my free time.

My time is not free. I did RF design and ran a 2way shop for about 11
years. I guess that having more years of experience entitles me to
tell you how to run your life.

I suggest you not try to teach those who know
more than you your "facts".

Yep. Quantity is a good substitute for quality. Unfortunately, I
have to agree with most of your comments.

The facts a to have the beat frequency, you need two signals within
15kHz or so of each other. Those signals must be mixed, which means at
least one must be non-linear.

Signals are not linear or non-linear, but are usually called
"distorted" if not a clean sine wave. The circuitry through which the
signals pass can be linear or non-linear. Linear circuits do not mix,
unless overloaded. If the mixing circuit is non-linear, you can use
harmonics to create more mix combinations that result in 15KHz
frequency difference.
n*f1 +/- m*f2 = beat_freq
where n and m are integers.

This will give you a beat frequency in
the audio spectrum.

Yep. However, my hearing is kinda marginal and needs something lower
than about 10-12KHz.

Once you have this, you need something to generate a strong enough
magnetic field in the audio frequency range to act as a driver, and
something close enough and made of a magnetic material to vibrate.

True. There has to be an electric to audio transducer somewhere.
However, there are situations where the mechanism is obscure. For
example, when I moved into my house in Ben Lomond in 1973, the 200MHz
radar on nearby Mt Umunhum was running megawatts pointed straight at
me. Every time the rotating dish went by, my hi-fi would produce buzz
out of the speakers at the pulse repetition frequency. That was easy
enough to understand. However, the coils inside my kitchen electric
oven also went twang as the beam went by, which was more difficult to
explain. There had to be a rusty connection or bolt, but I couldn't
find one. Maybe the oven or coils were resonant at 200 Mhz. I never
did figure out how it worked.

I've seen a fair number of spurious emissions over the years (mostly
from VHF/UHF radios). Every one of them has been RF, and none of them
have created audio oscillations.

When I transmit on my VHF HT near my comptah speakers, they buzz
loudly. Does that count?

A few months ago we even had a case right here where a VHF radio in a
county bus had a spur on the input to the local 2 meter ham repeater.
Once again, no indication in the bus this was occurring. The county
found out about it only after the hams contacted them.

The county should have had a new digital or narrow band radio. Was
this a new radio? I usually look at the output on a spectrum analyzer
before letting something go out the door.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Indoor FM boost with no cables?
 

On 7/31/2014 7:03 PM, Jeff Liebermann wrote:
On Thu, 31 Jul 2014 10:19:38 -0400, Jerry Stuckle
wrote:

And of course there's the now infamous hair salon in San Antonio, Tx,
with the fluorescent light ballasts that caused problems to AT&T Cell
phone network (and it seems this is not the only business with this
problem).

The hair salon refused to do anything about it so they got a letter
from the FCC.
http://www.commlawblog.com/2013/10/articles/enforcement-activities-fines-f/bulbs-behind-bars-ii-fcc-goes-after-hair-salon-lighting-fixture/
Seems to be a common problem. Here's one in Smog Angeles:
http://www.pcworld.com/article/2095940/la-buildings-lights-interfere-with-cellular-network-fcc-says.html
My guess(tm) is electronic ballasts.


Yes, I know the story, Jeff. That's why I quoted it. And it's not the
only business which has had problems with GE ballasts. GE has claimed
they've fixed the problem with additional filtering. We'll see.

My favorite was GPS interference from TV amplifiers:
http://gpsworld.com/the-hunt-rfi/
I was not involved in either the cause or solution.


This does not surprise me. There have been a number of problems with
such units, typically from overseas. Many of them are sold in the U.S.
without the required FCC Certification - which puts an unwitting owner
at risk as well as those around him/her.

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

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

Indoor FM boost with no cables?
 

On 7/31/2014 7:29 PM, Jeff Liebermann wrote:
On Thu, 31 Jul 2014 08:16:29 -0400, Jerry Stuckle
wrote:

Yes, I know how it works - I've held both amateur and commercial
licenses for well over 40 years and worked on almost everything from $40
CB sets to multimillion dollar mainframe computers.

Well let's see... I got my novice license when I was 15, so that means
I've had a ham license (various call signs) for 51 years. My FCC
First Class and now GROL for about 46 years.

I've even done some design in my free time.

My time is not free. I did RF design and ran a 2way shop for about 11
years. I guess that having more years of experience entitles me to
tell you how to run your life.

I suggest you not try to teach those who know
more than you your "facts".

Yep. Quantity is a good substitute for quality. Unfortunately, I
have to agree with most of your comments.


True. Fortunately, all of my experience has been "quality".

The facts a to have the beat frequency, you need two signals within
15kHz or so of each other. Those signals must be mixed, which means at
least one must be non-linear.

Signals are not linear or non-linear, but are usually called
"distorted" if not a clean sine wave. The circuitry through which the
signals pass can be linear or non-linear. Linear circuits do not mix,
unless overloaded. If the mixing circuit is non-linear, you can use
harmonics to create more mix combinations that result in 15KHz
frequency difference.
n*f1 +/- m*f2 = beat_freq
where n and m are integers.


Just because a signal is not a sine wave does not mean it is distorted.
A mix of several different frequencies (i.e. music, voice) produces
something far from resembling a sine wave - but it is not distorted. I
won't get into the math here - but there is a solid foundation.

And if a linear circuit is overloaded, it is no longer linear.
Harmonics may or may not come into play - it all depends on the
characteristics of the circuit. For instance, the harmonics of an FM
band (88-106 MHz) amplifier are nowhere near the audio range. And mix
combinations are even less likely to be anywhere near the audio range.

This will give you a beat frequency in
the audio spectrum.

Yep. However, my hearing is kinda marginal and needs something lower
than about 10-12KHz.


Audio range is generally considered to be 20Hz - 15Khz. But that is a
general range; individual people can have greater or lesser ranges.

Once you have this, you need something to generate a strong enough
magnetic field in the audio frequency range to act as a driver, and
something close enough and made of a magnetic material to vibrate.

True. There has to be an electric to audio transducer somewhere.
However, there are situations where the mechanism is obscure. For
example, when I moved into my house in Ben Lomond in 1973, the 200MHz
radar on nearby Mt Umunhum was running megawatts pointed straight at
me. Every time the rotating dish went by, my hi-fi would produce buzz
out of the speakers at the pulse repetition frequency. That was easy
enough to understand. However, the coils inside my kitchen electric
oven also went twang as the beam went by, which was more difficult to
explain. There had to be a rusty connection or bolt, but I couldn't
find one. Maybe the oven or coils were resonant at 200 Mhz. I never
did figure out how it worked.


Could be - but what was radar doing at 200Mhz? Not only will it
interfere with both business band and amateur frequencies, but the large
beam width would make it pretty useless. And as weather radar, it would
be useless.

I've seen a fair number of spurious emissions over the years (mostly
from VHF/UHF radios). Every one of them has been RF, and none of them
have created audio oscillations.

When I transmit on my VHF HT near my comptah speakers, they buzz
loudly. Does that count?


Whatever trips your trigger.

A few months ago we even had a case right here where a VHF radio in a
county bus had a spur on the input to the local 2 meter ham repeater.
Once again, no indication in the bus this was occurring. The county
found out about it only after the hams contacted them.

The county should have had a new digital or narrow band radio. Was
this a new radio? I usually look at the output on a spectrum analyzer
before letting something go out the door.


This is an 800 Mhz radio, not VHF. Only the spur was on VHF.

But then it appears you're just trolling like you usually do. The
difference is this time I'm not going to fall for it. You can have the
last word.

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

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

Indoor FM boost with no cables?
 

On 7/31/2014 7:29 PM, Jeff Liebermann wrote:

My time is not free. I did RF design and ran a 2way shop for about 11
years. I guess that having more years of experience entitles me to
tell you how to run your life.


I should also add - "ran a 2way shop for about 11 years". That hardly
qualifies you as an "expert". As for "RF design" - what did you design
- TV amplifiers?

And I never said my time was free - I said in my free time. It's a
hobby I enjoy. But trolls don't understand that.

Again - I'm not falling for your trolling again - you can have the last
word.

--
==================
Remove the "x" from my email address
Jerry Stuckle

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

Indoor FM boost with no cables?
 

On Thu, 31 Jul 2014 20:24:10 -0400, Jerry Stuckle
wrote:

Yes, I know the story, Jeff. That's why I quoted it. And it's not the
only business which has had problems with GE ballasts. GE has claimed
they've fixed the problem with additional filtering. We'll see.

Here's more on the story on noisy GE electronic ballasts:
http://www.commlawblog.com/2014/02/articles/enforcement-activities-fines-f/bulbs-behind-bars-iii-more-lighting-fixtures-mess-up-mobile-data-service/
However, GE has found that a small number of units of the
2-lamp ballasts identified above that were manufactured
prior to September 19, 2011 have produced unintentional
high-frequency radio emissions that have the potential to
cause interference with certain types of wireless communications.

...the product codes for the problem ballasts were 72262 and 72266.

Note that the bulletin was NOT publicly distributed by GE and that
there was no voluntary recall by GE. Looks like GE has effectively
buried the problem. With only two documented interference complaints,
both with clueless business owners, I don't believe that the FCC has
enough cause to act on the matter. However, I will give GE credit for
somewhat publicly admitting that there was a problem, even if they did
bury it.





--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Indoor FM boost with no cables?
 

On 7/30/2014 9:40 AM, 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.

I'm unclear, is mW microwatts or milliwatts as you wrote it? The reason
I ask is that a 500 milliwatt transmitter would certainly have a
receivable distance much greater than 100 feet, no?

--

Rick

Indoor FM boost with no cables?
 

On 7/31/2014 9:28 PM, Jeff Liebermann wrote:
On Thu, 31 Jul 2014 20:24:10 -0400, Jerry Stuckle
wrote:

Yes, I know the story, Jeff. That's why I quoted it. And it's not the
only business which has had problems with GE ballasts. GE has claimed
they've fixed the problem with additional filtering. We'll see.

Here's more on the story on noisy GE electronic ballasts:
http://www.commlawblog.com/2014/02/articles/enforcement-activities-fines-f/bulbs-behind-bars-iii-more-lighting-fixtures-mess-up-mobile-data-service/
However, GE has found that a small number of units of the
2-lamp ballasts identified above that were manufactured
prior to September 19, 2011 have produced unintentional
high-frequency radio emissions that have the potential to
cause interference with certain types of wireless communications.

...the product codes for the problem ballasts were 72262 and 72266.

Note that the bulletin was NOT publicly distributed by GE and that
there was no voluntary recall by GE. Looks like GE has effectively
buried the problem. With only two documented interference complaints,
both with clueless business owners, I don't believe that the FCC has
enough cause to act on the matter. However, I will give GE credit for
somewhat publicly admitting that there was a problem, even if they did
bury it.






Yes, Jeff, I am quite aware of the entire story. There is a lot more
about it than you have found. I just didn't post it here because it is
unrelated to the newsgroup. However, there have been several articles
about it in the technical newsletters.

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

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

Indoor FM boost with no cables?
 

On 7/31/2014 9:29 PM, rickman wrote:
On 7/30/2014 9:40 AM, 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.

I'm unclear, is mW microwatts or milliwatts as you wrote it? The reason
I ask is that a 500 milliwatt transmitter would certainly have a
receivable distance much greater than 100 feet, no?


According to standards, mW is milliwatts. uW (actually, greek "mu"W but
I'm not using a charset here that defines it, so the standard is "uW")
would be microwatts.

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

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

Indoor FM boost with no cables?
 

On Thu, 31 Jul 2014 20:34:32 -0400, Jerry Stuckle
wrote:

Could be - but what was radar doing at 200Mhz? Not only will it
interfere with both business band and amateur frequencies, but the large
beam width would make it pretty useless. And as weather radar, it would
be useless.

Left over from the cold war. Someone forgot to turn it off or
something.

214-236 Mhz. Not sure about the pulse repetition frequency but it had
to be fairly low audio frequency in order to obtain the long range. At
3500ft elevation, the radar range is 84 miles.

Some of the URL's below show 420 to 450 MHz for the AN/FPS-24. That's
wrong for the early models. Built in 1957 and pulled the plug in
1980:
http://en.wikipedia.org/wiki/Mount_Umunhum
http://en.wikipedia.org/wiki/AN/FPS-24
http://www.radomes.org/museum/equip/fps-35.html
https://www.google.com/search?q=mt+umunhum+radar&tbm=isch
https://www.youtube.com/watch?v=nqfsWBZR8XM
I can see the building through the trees from my house. Amazing what
5 megawatts can do.

The dish rotated at the then standard rate of two revolutions per
minute. So, every 30 seconds, there was a blast of buzz from the
hi-fi, 2way, phone, and oven (I didn't have a TV back then). I
learned to automatically stop talking just before the bzzzzzt, and
continue talking after it was gone in about one second. When they
pulled the plug in 1980, I continued to do this unconsciously for
several months. Incidentally, I tried bypasses and ferrite beads.
They helped, but didn't totally eliminate the buzz. Transcribing
vinyl records to 1/4" tape was a lost cause.



--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Indoor FM boost with no cables?
 

On Thu, 31 Jul 2014 20:37:16 -0400, Jerry Stuckle
wrote:

I should also add - "ran a 2way shop for about 11 years".

You really shouldn't truncate my quotes. What I said was
"I did RF design and ran a 2way shop for about 11 years."
That means that I bounced back and forth between RF design and 2way
radio for about 11 years with a few gaps in between. The elapsed time
was from 1971 through about 1983.

Somewhat after graduating college, I worked for Communitronix
repairing CB and commerical radios (mostly CB) and installing radios
in cement mixers. I vaguely recall that the owner fired me, probably
for good reason.

I then went to work for Pacific Mobile Communications in Stanton CA,
which still exists today. Mostly, it was maintaining three repeater
sites in the L.A. area.
http://802.11junk.com/jeffl/pics/Old%20Repeaters/index.html
The building to the right was the main site on Santiago Pk:
http://www.trabucooutdoors.com/assets/images-1/odds_ends/santiagopk.jpg

PMC is associated with Alpha Electronics, which made sub-audible tone
boards for various radios, DC and tone remotes, etc. The later tone
boards used hybrids. We had our own hybrid production line, PCB
etching facility, assembly line, and production test. When not
dealing with the radios, I helped design all of these.

After that, was hired by Standard Communication (SCC) of Wilmington to
integrate various products, mostly from Alpha Electronics, into their
product line. I didn't stay long, mostly because of the 1.5 hr
commute.

Somewhat later, I left the area and eventually landed in the Santa
Clara area, where I worked for Intech Inc designing mostly marine
radios. Finding photos is a bit difficult, but I did manage to find
one of the Intech M3600 2-30 MHz HF SSB marine radio:
http://www.hellocq.net/forum/read.php?tid=226493
Offhand, I recall doing about 12 products in 9.5 years. Numbers and
details if you want them. Oh, some manuals here for the AN-SRD/21 and
AN-SRD/22 direction finders for the USCG.
http://802.11junk.com/jeffl/AN-SRD-21/
http://802.11junk.com/jeffl/AN-SRD-22/

After Intech, I went to work for Granger Assoc where I designed a
900MHz SCADA system to be used by Southern Calif Edison for remote
power factor capacitor switching. I did the transmitter, power amp,
RF switching, duplexer, and whatever nobody else wanted to do.

I left Granger in about 1983 to become a real estate speculator,
consultant, and student. I decided to turn my hobby into a profession
and become a computer consultant. I attached myself to computer store
and built up the repair business, while maintaining my RF consulting
business.

Since most of my experience since that time has been in on radio
related areas, I won't bother to detail them. There were also some
short term jobs and contracts mixed in with the aforementioned work
that are not worth mentioning.

That hardly
qualifies you as an "expert".

I do not claim to be an expert. What I said was
"I guess that having more years of experience entitles
me to tell you how to run your life."
You indicated that on the same basis, you could tell
Mr Lostgallifreyan to:
"I suggest you not try to teach those who know
more than you your "facts".
I would appreciate it if you would extend me the same courtesy and not
try to teach me your "facts".

As for "RF design" - what did you design
- TV amplifiers?

See detail above. List of products and responsibility if you want
them. I'll have to do some digging to find them all, but am willing
if you think it will help you in some way.



--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Indoor FM boost with no cables?
 

On Thu, 31 Jul 2014 21:29:11 -0400, rickman wrote:

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.

I'm unclear, is mW microwatts or milliwatts as you wrote it? The reason
I ask is that a 500 milliwatt transmitter would certainly have a
receivable distance much greater than 100 feet, no?

He's right. The receivers aren't that sensitive. For example, I just
excavated the Silicon Labs Si470-31 data sheet, which shows an FM
sensitivity of 1.1 uV into 50 ohms for a S+N/N ratio of 26dB. The
reason is the wide (200KHz for FM and 500KHz HD Radio) occupied
bandwidths. The bigger the bandwidth, the more noise gets in, and the
lower the sensitivity. Crudely, double the bandwidth and lose -3dB
(i.e. half) in sensitivity.

Much depends on the antennas and the field strength sensitivity. Let's
see what the Friis Equations produces. If I assume a best case of a
2dB gain dipole at the transmitter, but a crude earphone cord antenna
at the receiver (-3dB at best). Then what I get is:
TX 27dBm (500 mw)
TX ant 2dB
path loss ????
RX ant -3dB
RX sens -107dBm
Path Loss = 27 + 2 -3 -107 = 81 dB
Plugging into:
http://www.proxim.com/products/knowledge-center/calculations/calculations-free-space-loss
I get 1.7 miles at 100 MHz. Looks like it should work.

Things get messy when I run the numbers again with the typical
receiver sensitivity found in analog receivers. These have typical
sensitivity of 9 dBf. That's dB(Femtowatts) or 10^-15 watts
reference. Converting to a milliwatts reference, that's:
9*10^-15 watts / 1*10^-3 watts = 9*10^-12
converting to dB, or 10 log of the ratio:
dB = 10*log(9*10^-12) = 10 * (-11) = -110 dBm
which is allegedly 3dB more sensitive than the all digital chip. I
don't believe it. So, with 3dB less sensitivity, you should get about
half the range or 0.85 miles.




--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Indoor FM boost with no cables?
 

On 7/31/2014 9:47 PM, Jerry Stuckle wrote:
On 7/31/2014 9:29 PM, rickman wrote:
On 7/30/2014 9:40 AM, 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.

I'm unclear, is mW microwatts or milliwatts as you wrote it? The reason
I ask is that a 500 milliwatt transmitter would certainly have a
receivable distance much greater than 100 feet, no?


According to standards, mW is milliwatts. uW (actually, greek "mu"W but
I'm not using a charset here that defines it, so the standard is "uW")
would be microwatts.

I'm not asking about the standard, I'm asking what you meant by mW. Why
do you say with a power level of 500 mW (27 dBm) a transmitter would
only have a range of 100 feet? With the low bandwidth we are discussing
this seems to be *very* short.

--

Rick

Indoor FM boost with no cables?
 

"Lostgallifreyan" wrote in message
. ..

Michael Black wrote in
news:alpine.LNX.2.02.1407260017460.20123@darkstar. example.org:

Modify the radio so coax can be attached, and feed it from the good
antenna outside (or even just positioned well inside).

Or, buy a radio that already has an external antenna jack.


Now that would be cheating. :) Actually the one I bought does have one, but
the point was convenience, allowing local tuning as usual but with no
unwanted wires trailing around as I carry a radio between rooms while
working.

If it were practical I imagine we'd all be doing it, I just wondered if
there
might be soem compromise I can use, but likely not one that isn't already
standard practise.

If you will be changing to a different station more often than every hour or
two, stop reading now. I cannot help you.

You can buy a low-power FM broadcaster for considerably less than US$100,
according to a few quick checks I made online just now. If you have any
location in your flat where you get reliable reception of your favorite
station(s), locate a receiver there and connect the audio out -- headphone
jack or speaker terminals -- into the FM broadcaster and choose an unused
frequency on the FM radio spectrum for the FM broadcaster. Then, listen to
that frequency. Your source for audio could be almost any device with an
AUDIO OUT jack: AM radio, FM radio, CD player, computer audio (for streaming
services).

I know it works reliably. Before I retired, my desk in a metal building was
far from the nearest window and AM radio listening was almost impossible,
with squeals and squawks from the computers. I used an FM broadcaster to
send the audio of my favorite station across the room from a location by a
window to an FM radio on my desk. I powered the AM radio and the FM
broadcaster from two wall transformers. It literally worked for years, as I
never turned it off.

Power consumption is insignificant. More details on request.

"Sal"
KD6VKW

Indoor FM boost with no cables?
 

"Jeff Liebermann" wrote in message
...

On Thu, 31 Jul 2014 21:29:11 -0400, rickman wrote:

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.

I'm unclear, is mW microwatts or milliwatts as you wrote it? The reason
I ask is that a 500 milliwatt transmitter would certainly have a
receivable distance much greater than 100 feet, no?

He's right. The receivers aren't that sensitive. For example, I just
excavated the Silicon Labs Si470-31 data sheet, which shows an FM
sensitivity of 1.1 uV into 50 ohms for a S+N/N ratio of 26dB. The
reason is the wide (200KHz for FM and 500KHz HD Radio) occupied
bandwidths. The bigger the bandwidth, the more noise gets in, and the
lower the sensitivity. Crudely, double the bandwidth and lose -3dB
(i.e. half) in sensitivity.

Much depends on the antennas and the field strength sensitivity. Let's
see what the Friis Equations produces. If I assume a best case of a
2dB gain dipole at the transmitter, but a crude earphone cord antenna
at the receiver (-3dB at best). Then what I get is:
TX 27dBm (500 mw)
TX ant 2dB
path loss ????
RX ant -3dB
RX sens -107dBm
Path Loss = 27 + 2 -3 -107 = 81 dB
Plugging into:
http://www.proxim.com/products/knowledge-center/calculations/calculations-free-space-loss
I get 1.7 miles at 100 MHz. Looks like it should work.

Things get messy when I run the numbers again with the typical
receiver sensitivity found in analog receivers. These have typical
sensitivity of 9 dBf. That's dB(Femtowatts) or 10^-15 watts
reference. Converting to a milliwatts reference, that's:
9*10^-15 watts / 1*10^-3 watts = 9*10^-12
converting to dB, or 10 log of the ratio:
dB = 10*log(9*10^-12) = 10 * (-11) = -110 dBm
which is allegedly 3dB more sensitive than the all digital chip. I
don't believe it. So, with 3dB less sensitivity, you should get about
half the range or 0.85 miles.
================================================== =====

When I was in the Navy, I was detached from my ship for a short school. I
bought a Radio Shack FM broadcaster that used a 9v battery. A couple of
guys and I fashioned a folded dipole for the FM band as the transmit antenna
and used a BCB radio for the audio input. We pushed the folded dipole a few
feet out a second-story window on a broom handle and proceeded across the
base to see how far we could hear our signal on a portable FM radio.

We went about a 1000 feet before the signal became useless, although there
were some dropouts closer than that. I do not know the output of the device
in milliWatts, but I suspect it is much less than the nominal 100 milliWatts
that limits the no-license operation.

"Sal"

Indoor FM boost with no cables?
 

"Sal M. O'Nella" wrote in message ...



major snipping

less than the nominal 100 milliWatts
that limits the no-license operation.
================================================== ====

I don't think that 100 milliWatt limit exists now, if it ever did. The FCC
provides guidance and the limit appears to be under a microWatt in the FM
band. I'd be happy to get clarification.

"Sal"

Indoor FM boost with no cables?
 

On 8/1/2014 12:37 AM, rickman wrote:
On 7/31/2014 9:47 PM, Jerry Stuckle wrote:
On 7/31/2014 9:29 PM, rickman wrote:
On 7/30/2014 9:40 AM, 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.

I'm unclear, is mW microwatts or milliwatts as you wrote it? The reason
I ask is that a 500 milliwatt transmitter would certainly have a
receivable distance much greater than 100 feet, no?


According to standards, mW is milliwatts. uW (actually, greek "mu"W but
I'm not using a charset here that defines it, so the standard is "uW")
would be microwatts.

I'm not asking about the standard, I'm asking what you meant by mW. Why
do you say with a power level of 500 mW (27 dBm) a transmitter would
only have a range of 100 feet? With the low bandwidth we are discussing
this seems to be *very* short.


I follow the standards.

Not much more than that. Remember - the commercial FM band has +/-
75kHZ deviation. Additionally, there are limits as to the antenna on
Part 15 devices - you can't, for instance, place a 6db gain antenna 200'
in the air.

Realtors around here use them to advertise houses; they place one in the
house with a recording that describes the house with a sign out front
showing the frequency. Reception from the street is typically within a
couple of houses either side.

Our college radio station ran 10 watts to a 3db gain antenna on top of
one of the dorms. The dorm was only 3 stories plus attic, so the
antenna was maybe 40-45 feet in the air. Good coverage was about a 2-3
mile radius with a typical portable receiver (or car); an external
antenna on the receiver obviously extended that.

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

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

Indoor FM boost with no cables?
 

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!

Indoor FM boost with no cables?
 

On 8/1/2014 8:00 AM, Jerry Stuckle wrote:
On 8/1/2014 12:37 AM, rickman wrote:
On 7/31/2014 9:47 PM, Jerry Stuckle wrote:
On 7/31/2014 9:29 PM, rickman wrote:
On 7/30/2014 9:40 AM, 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.

I'm unclear, is mW microwatts or milliwatts as you wrote it? The reason
I ask is that a 500 milliwatt transmitter would certainly have a
receivable distance much greater than 100 feet, no?


According to standards, mW is milliwatts. uW (actually, greek "mu"W but
I'm not using a charset here that defines it, so the standard is "uW")
would be microwatts.

I'm not asking about the standard, I'm asking what you meant by mW. Why
do you say with a power level of 500 mW (27 dBm) a transmitter would
only have a range of 100 feet? With the low bandwidth we are discussing
this seems to be *very* short.


I follow the standards.

Not much more than that. Remember - the commercial FM band has +/-
75kHZ deviation. Additionally, there are limits as to the antenna on
Part 15 devices - you can't, for instance, place a 6db gain antenna 200'
in the air.

Realtors around here use them to advertise houses; they place one in the
house with a recording that describes the house with a sign out front
showing the frequency. Reception from the street is typically within a
couple of houses either side.

Our college radio station ran 10 watts to a 3db gain antenna on top of
one of the dorms. The dorm was only 3 stories plus attic, so the
antenna was maybe 40-45 feet in the air. Good coverage was about a 2-3
mile radius with a typical portable receiver (or car); an external
antenna on the receiver obviously extended that.

Ok, if you are talking about 500 milliWatts, how do you get 100 feet
from that?

--

Rick

Indoor FM boost with no cables?
 

On 8/1/2014 8:45 AM, rickman wrote:
On 8/1/2014 8:00 AM, Jerry Stuckle wrote:
On 8/1/2014 12:37 AM, rickman wrote:
On 7/31/2014 9:47 PM, Jerry Stuckle wrote:
On 7/31/2014 9:29 PM, rickman wrote:
On 7/30/2014 9:40 AM, 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.

I'm unclear, is mW microwatts or milliwatts as you wrote it? The
reason
I ask is that a 500 milliwatt transmitter would certainly have a
receivable distance much greater than 100 feet, no?


According to standards, mW is milliwatts. uW (actually, greek "mu"W
but
I'm not using a charset here that defines it, so the standard is "uW")
would be microwatts.

I'm not asking about the standard, I'm asking what you meant by mW. Why
do you say with a power level of 500 mW (27 dBm) a transmitter would
only have a range of 100 feet? With the low bandwidth we are discussing
this seems to be *very* short.


I follow the standards.

Not much more than that. Remember - the commercial FM band has +/-
75kHZ deviation. Additionally, there are limits as to the antenna on
Part 15 devices - you can't, for instance, place a 6db gain antenna 200'
in the air.

Realtors around here use them to advertise houses; they place one in the
house with a recording that describes the house with a sign out front
showing the frequency. Reception from the street is typically within a
couple of houses either side.

Our college radio station ran 10 watts to a 3db gain antenna on top of
one of the dorms. The dorm was only 3 stories plus attic, so the
antenna was maybe 40-45 feet in the air. Good coverage was about a 2-3
mile radius with a typical portable receiver (or car); an external
antenna on the receiver obviously extended that.

Ok, if you are talking about 500 milliWatts, how do you get 100 feet
from that?


Portable receivers have notoriously poor antennas and receive
sensitivity. A whip antenna is better, but awkward. An external
antenna on a good receiver will receive a fair amount further - but
that's not portable. Plus building, etc. will attenuate the signal
(concrete is really bad - add steel rebar and it's even worse).

Like anything else - you *can* get farther than 100 feet, but that's
about all you can expect reliably.

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

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

Indoor FM boost with no cables?
 

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. But that's trolls for you.


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

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

Indoor FM boost with no cables?
 

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.

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.

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.

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.

Indoor FM boost with no cables?
 

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

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

Indoor FM boost with no cables?
 

Jerry Stuckle wrote:
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.

I never doubt that!
But I am sure I know more about it than you!
And so do many others here.
It is you that is *thinking* he has a lot of knowledge, but knows
absolutely no facts. Not that this is required to employ people, just
make sure you never toucht the stuff yourself!

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).

It was you that was coming up with picowatts when others suggested
nanowatts. That tells enough, doesn't it?

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.

No, not at all. It is the EU regulation for unlicensed devices operating
in the 100 MHz broadcast band that they must not emit more than 50nW.

Now I'm sure that in America everything is bigger and the rules are better
(not the receivers, apparently), but you are not going to convince me that
the same equipment in America emits 100-500mW. That is just ignorance
on your side.

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.

Oh yes I do! dBm, meaning dB over a milliwatt.
And in the cable industry, dBuV, meaning dB over a microvolt.

In America, where everything is bigger, probably dB over a millivolt,
but not expressed as dBm!

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

That's you, I take?

Indoor FM boost with no cables?
 

On 8/1/2014 7:45 AM, rickman wrote:
On 8/1/2014 8:00 AM, Jerry Stuckle wrote:
On 8/1/2014 12:37 AM, rickman wrote:
On 7/31/2014 9:47 PM, Jerry Stuckle wrote:
On 7/31/2014 9:29 PM, rickman wrote:
On 7/30/2014 9:40 AM, Jerry Stuckle wrote:
On 7/30/2014 1:22 AM, Lostgallifreyan wrote:
Jerry Stuckle wrote in

Our college radio station ran 10 watts to a 3db gain antenna on top of
one of the dorms. The dorm was only 3 stories plus attic, so the
antenna was maybe 40-45 feet in the air. Good coverage was about a 2-3
mile radius with a typical portable receiver (or car); an external
antenna on the receiver obviously extended that.

Ok, if you are talking about 500 milliWatts, how do you get 100 feet
from that?


I concur with the 100ft number with 500 milliwatts.
If everything is right you can get a little more, but don't
rotate the radio or move your body to the wrong spot.
I have a transmitter that is switchable between 500mw and 1 watt.
I might be able to get 200 ft but the radio needs to be held just right.
It works fine around the house and yard with 6db of attenuation before
the rubber ducky antenna.

Mikek

---
This email is free from viruses and malware because avast! Antivirus protection is active.
http://www.avast.com

Indoor FM boost with no cables?
 

On 8/1/2014 1:48 PM, Rob wrote:
Jerry Stuckle wrote:
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.

I never doubt that!
But I am sure I know more about it than you!
And so do many others here.
It is you that is *thinking* he has a lot of knowledge, but knows
absolutely no facts. Not that this is required to employ people, just
make sure you never toucht the stuff yourself!


Wrong again. But like all trolls, you THINK you know things you don't.
The difference between ignorance and stupidity - ignorance can be
cured. And like all trolls, you are just plain stupid.

And as a matter of fact, I train the people who work with me. I've been
in the electronics business for over 40 years, working on everything
from $40 dollar CB sets to multi-million dollar computer mainframes. I
doubt you've even touched a soldering iron.

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).

It was you that was coming up with picowatts when others suggested
nanowatts. That tells enough, doesn't it?


Check back - I wasn't the one who mentioned picowatts. However, like
all trolls, you can't read, either.

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.

No, not at all. It is the EU regulation for unlicensed devices operating
in the 100 MHz broadcast band that they must not emit more than 50nW.


That's fine for the EU. It is different in the U.S.

Now I'm sure that in America everything is bigger and the rules are better
(not the receivers, apparently), but you are not going to convince me that
the same equipment in America emits 100-500mW. That is just ignorance
on your side.


I didn't say the same equipment. I said it is legal in the United States.

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.

Oh yes I do! dBm, meaning dB over a milliwatt.
And in the cable industry, dBuV, meaning dB over a microvolt.


In your country, maybe. But here, most cable technicians when talking
dB are talking dBuV. But one again you show your ignorance.

In America, where everything is bigger, probably dB over a millivolt,
but not expressed as dBm!


I never said that, either. But like the troll you are, you can't get
anything straight.

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

That's you, I take?


You all over. As you just proved once again.

But that's only expected from an anonymous poster with an invalid email
address and no call sign (probably aren't a ham, either). Too afraid to
let his boss know the trash he's posting - he'd get fired.

Now I'll let you have the last word. Trolls always need to have the
last word.


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

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