John Smith I wrote:

But .0000000017 watts?

I thought we were talking a full watt!

(more of a pirate in me than some grin)

JS

John Smith I wrote:

Anyway, I would pursue this much differently.

Indian reservations are exempt from MANY of the rules, regulations and
laws the rest of us non-indigenous peoples are subject too.

I'd see if the above were not a factor in all this.

JS

wrote in message
oups.com...
John,

So, say I had a CW oscillator on the colorburst frequency. I'll shunt
the output
with a 50 ohm resistor to ground. I'll put a random wire at the top of
the
resistor.

Basic equations yield P = (EE) / R

If R is 50 Ohms and maximum output power is 1.7e-9 watts, then E
is 4.1e-5 volts.

So, would a measurement of 40 microvolts or less across the resistor
be satisfactory?

Thanks,

The Eternal Squire

I think it would be about 300 uV across 50 ohms ( I think you are off by
about an order of magnitude). Yes, I think that would be okay. A good place
to understand this stuff is on the ARRL site. Look into the BPL and RFI
things there. Read everything you can find about this subject. If you
research this thoroughly, you will find allies in the field, I'm sure.

My intent here is not to discourage you in your project, but to encourage
you to think critically. Always ask yourself why this has not been done
before. Most of the time there is a reason, but sometimes (a small
percentage of the time) it is because nobody has had an interest in the
subject.

But, you didn't ask for my philosophy. I sometimes get carried away. I
apologize for that.

Cheers and 73,
John

If (mind you, IF) I was going to make a device that would bootleg a signal
over a 30 mile range, the LAST frequency I would pick is one that had a real
good chance of messing up somebody's color TV set in that radius.

Google on Mouser, crystal, and you will get HUNDREDS of cheap crystals that
aren't going to be messing up anybody's home entertainment devices. You
might also google for "emergency frequency" to keep away from the Coast
Guard's "hit the red button" frequencies.

If it twer me, I'd probably find a quiet spot on 80 meters for the little
rugrats.

Jim



wrote in message
oups.com...
John,

So, say I had a CW oscillator on the colorburst frequency.

Okay, suppose I make a colorburst CW oscillator and shunt it with a 50
ohm resistor.
I'd put a random wire at the top of the resistor.

So from basic equations P = (EE)/R, with a power limit of 1.7 nanovolt
this gives a voltage limit of 0.6 microvolt.

I'm afraid I don't have a voltmeter or scope that goes that low.

The Eternal Squire

On Jan 25, 9:44 pm, "John" wrote:
wrote in oglegroups.com...

My question is this: so long as final output to the antenna is within
the requirement of part 15 unlicensed operation, is part 15 unlicensed
operation allowed within a band normally governed under part 97?
Part 15 operation would easily cover a 30 mile radius on 80M. http://www.access.gpo.gov/nara/cfr/w...7cfr15_06.html

Part 15.223 says in part...

"Subpart C_Intentional Radiators
Sec. 15.223 Operation in the band 1.705-10 MHz.

(a) The field strength of any emission within the band 1.705-10.0
MHz shall not exceed 100 microvolts/meter at a distance of 30 meters.
However, if the bandwidth of the emission is less than 10% of the center
frequency, the field strength shall not exceed 15 microvolts/meter or
(the bandwidth of the device in kHz) divided by (the center frequency of
the device in MHz) microvolts/meter at a distance of 30 meters,
whichever is the higher level."

For CW operation, your bandwidth is zero for all practical purposes. You
will therefore be allowed 15 uV/m at 30 meters.

From this I made a very crude estimate of your allowed transmitter output
power. Assuming your transmitter antenna is 100% efficient and radiates
hemispherically, your transmitter output power is allowed to be no more than
about 1.7 nanowatts (1.7e-9 watts). For ideal circumstances (0 dB receiver
antenna gain, 100% efficient receiver antenna), you would get less than 5 uV
at a receiver 400 meters away. I stress that this is for ideal
circumstances. If your transmitting antenna is less efficient, you can run
more power, but less of your power gets launched. How efficient is that
antenna, anyway? On the other hand, your antenna may have some directivity
which would further limit your power.

This is making my head hurt.

All that can really be said about this estimate is that, to be safe, you
should not have much more than about 2 nanowatts output power unless you
have the ability to measure the field strength according to regulations.

Good luck with your project.

73,
John

) writes:

What I want to do is provide each kid with a popcorn CW transceiver for
the colorburst frequency (3579 khz), a key, a short random wire, and a
battery. That way they could practice amongst themselves with
myself as occasional net control.

The last thing in the world you want to do is give them the ability to
send and receive. Because then you'll get a bunch of senders and nobody
who can receive.

I made the same mistake when I was ten and got a morse code set. Two
units connected by wires, and you could switch between a morse sounder,
a light bulb or a buzzer. It was great for sending away, but the problem
was there was nobody to receive. And sending didn't mean a
thing in learning to receive.

I think it's correct to believe that youngsters would be interested
in morse code, a "secret language" at an age when "secret language"
means something.

But I don't see this helping.

You need to send to them, something they don't need licenses for or
a worry about whether the transmitter needs a license or not. But
then, they do need receivers. Only later will they have the ability
to communicate with morse code.

They don't need license-free transmitters to get a feel for ham
radio. They can talk (and if they know morse code, send) as third
parties over your station. You can build up simple receivers for
them, or better yet get them interested in building their own simple
receivers, and then listen to a ham band or your code practice
transmissions.

Building the receivers is a way to get them enthused about the hobby,
if done right. Again, getting the thing to work is a sense of
accomplishment, and it doesn't matter how simple the receiver might
be.

Charles Kitchin has had some simple regen receivers in QST in recent
years, using easy to get parts. I looked at one and everything could
come out of a good junk box. He had one that used a color subcarrier
crystal, again an easy to get part and which made it easy to tune. At
least one of the articles is at the ARRL website for all to access. Do
a websearch on his name, and you'll find that various clubs have done
it as a group project.

But also, when amateur radio is taught in schools, it always looks
good, because so many pass the test. I'm not so sure so many stick
with the hobby. Some of what's appealing about the hobby is that it's
not for everyone. I passed the test when I was 12, and it was something
to boast about at school, if school hadn't ended just before I got
the test results. I'm not convinced it would have had the same appeal
if it had been a regular school thing.

So often amateur radio benefits those school kids as a catalyst for
other things. And thus it's important that in this case getting the
ham license isn't the end goal. Getting them interested in learning,
getting them interested in building, even getting them interested
in communicating should be the goal. If they get something out of
building a simple radio receiver, then that's more important than
passing a test but getting nothing.

So letting them be third parties on your radio, and talking to distant
places, or even other reserves, is beneficial, whether or not it
leads them to getting a license. Getting them interested in building,
be it a radio receiver or some other gadget that can be made with
junk parts, is beneficial in itself. (And maybe a reservation isn't
the home of much electronic trash, but it's generally so easy to
get that they could learn from the act of taking things apart.)
Build up various means of sending morse code, and use that as
demonstration of things, rather than seeing morse code as the goal.
You can send morse by radio, and light, but you can also modulate
a light so you get a tone with morse code out of the speaker at
the receiving end. During WWII there was various activity using
the earth to send and receiver (since ham licenses were in suspension),
and that's another neat thing. You need to show them that there
are neat things, before they can pursue those things.

These things are the lure to get them interested in amateur radio.
They help to make going after the license appealing. But if it's
done right, they will benefit long before they make a decision about
getting a ham license.


Michael VE2BVW

In fourth grade (1952) a camp counselor had built a voice radio transmitter
that put out a signal on the broadcast band that we could hear all over the
campground. Was it illegal? HELL yes, it put out almost a watt into a
random wire antenna. Could it be heard a couple of miles away? HELL no. It
was a watt into a junk antenna.

That illegal transmitter put this kid into a 50 year career as an
electronics engineer with a lot of stops along the way.

My advice ... build a VOICE transmitter that has a couple of miles range and
let the kids have fun with it.

Licenses, we don't need no steenking licenses...

Jim


wrote in message
ups.com...
All,

I have a situation, and would like some opinions rather than flames on
how to handle it. My wife teaches at a public school just off the
Easter Arizona Navajo reservation. Lately, a junior school science
teacher is starting up a science club and has asked me to provide for
the amateur radio side of the club and be its control operator.

RST Engineering wrote:
That illegal transmitter put this kid into a 50 year career as an
electronics engineer with a lot of stops along the way.

My advice ... build a VOICE transmitter that has a couple of miles range and
let the kids have fun with it.

Licenses, we don't need no steenking licenses...

Jim



Andy writes:

And remember, it is much easier to ask for forgiveness than
for permission....

Do what you gotta do, but don't advertise. There is always someone
around who will try to make a big thing about it. And for goodness
sakes, don't tell anyone involved that what they are doing is illegal.
(Also, I would advise against posting this on newsgroups :))) )

Andy

AndyS wrote:

...
And remember, it is much easier to ask for forgiveness than
for permission....

Do what you gotta do, but don't advertise. There is always someone
around who will try to make a big thing about it. And for goodness
sakes, don't tell anyone involved that what they are doing is illegal.
(Also, I would advise against posting this on newsgroups :))) )

Andy


AndyS:

To sum that up? "If all else fails play dumb?"

Hey, it has worked for me in the past! chuckle

Regards,
JS

RST Engineering wrote:


That illegal transmitter put this kid into a 50 year career as an
electronics engineer with a lot of stops along the way.

My advice ... build a VOICE transmitter that has a couple of miles range and
let the kids have fun with it.

Licenses, we don't need no steenking licenses...

Jim


And they say the American spirit is dead? They say the men have all
been "feminized" in America? They say the pointy-head attorneys have
brain washed everyone with threats of litigation? They say the
multi-dollar corporations now run the people like a heard of sheep under
thought control?

Hmmm, I wonder ... grin

Warmest regards,
JS