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Author Topic: Let your child operate CW on air without a license  (Read 4463 times)
VK5EEE
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Posts: 939




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« Reply #30 on: August 14, 2017, 10:12:49 PM »

If I was a kid, I would be totally disinterested in sending CW over the Internet. What a waste of time! How inefficient! How difficult!

Let alone the AWFUL noises that pass as "CW" from those poor folks trying to use mice instead of keys.

On the other hand, among the static, pulling out a signal from the sky, just with my wire antenna, that's got some appeal. Next comes wanting to send some electricity down that wire.
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Long Live Real Human CW and wishing you many happy CW QSO - 77 - CW Forever
M0LEP
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« Reply #31 on: August 15, 2017, 03:07:08 AM »

Perth is the closest large Australian city to H.E. Holt

...for very Aussie values of "close". Wink
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W3TTT
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« Reply #32 on: August 15, 2017, 11:06:01 AM »

Although the precise relationship between power and field strength can depend on a number of additional factors, a commonly-used equation to approximate their relationship is:

((P * G) / (4 * pi * D^2)) = ((E^2) / (120 * pi))

30 uV/m at 30 meters is roughly 27 nanowatts EIRP (G=1).  The calculation is frequency-independent.
Yes, I saw that formula in the FCC documentation.  I did the same calculation and came to the same result.  My question was directed at the FCC rule itself. Since the formula is so old (used for AM Broadcast) it would seem to make no sense for 40 meters.  1 MHz at 30 meters is inside the near field.  At 7 Mhz it is halfway out into the far field.  Either way, it seems useless as a measure and the value is so small as to be useless too. 
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KB9CFH
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« Reply #33 on: August 15, 2017, 09:04:18 PM »

Maybe you need to read the help files with CwCom. You might find out you CAN use either a straight key OR an Iambic. As for BORING on the internet, How about not letting them do anything at all.
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VK5EEE
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« Reply #34 on: August 15, 2017, 10:47:31 PM »

No the answer is not to let them do less, but more. Let them use your radio, to a degree, let them have something to strive toward, some fun and some excitement, some WOW factor. The internet is what they need LESS of. And MORE of others.
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Long Live Real Human CW and wishing you many happy CW QSO - 77 - CW Forever
KB9CFH
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« Reply #35 on: August 16, 2017, 09:15:11 PM »

And if you have a whole bunch of kids that know morse code but don't have ham licenses, how about letting them use CwCom to send morse code to each other. Seems like a good idea to me.
Might even get them into using morse with flashlights and aldis lights ( ship to ship) with Superaldis 3 They could practice using the lights when there isn't a radio anywhere in the vicinity. Gee how about that.
And all this on the internet and not some dumb old radio.
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VK5EEE
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« Reply #36 on: August 16, 2017, 09:33:55 PM »

Whatever floats THEIR boat, not our opinions, is surely best? Let them choose! Give them ALL the choices. CW over Facebook, CW on your radio with or without a dummy load, CW Com, with a key, a mouse, keyboard, see what THEY want to do, and then facilitate or guide, or coax toward the radio if you like :-)

gee, I just looked it up, it is indeed COAX -- perhaps a good sign?
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W3TTT
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« Reply #37 on: August 24, 2017, 07:51:08 AM »

 Roll Eyes
Another idea - just thinking and just saying - and I might be shot down for this idea.

The official FCC rules for the broadcast band (540-1710 KHz) state the limit for a transmitter is "100mW".  One hundred milliwatts. That is a significant amount of power, it may be heard over a few hundred meters away.  Of course this type of use must not interfere with licensed broadcasters, and must accept interference from licensed etc.

What about a cw transmitter for a frequency that is between station channels and is between stations that are in the "grave yard"?  So, between channels means that the channels in the US are all on a 10 KHz even number, e.g. 1270, 1280, 1290, 1300 KHz, etc.  My suggestion here would be a cw transmitter on the 5 KHz between two channels, such as 1275, 1285, 1295, 1305 etc.  and so on.  Also, these frequencies are called the graveyard because many stations are assigned each frequency.  Unless there is a local (within 50 miles) station, all you hear on these graveyard frequencies is many stations all interfering with each other.  You can't pick out any distinct station.  The FCC allows this for some reason known only to themselves.  Also, when a cw transmitter is on a frequency that is 5 KHz away from any other transmitter, the hetrodyne will be at 5000 Hz, which is outside of the passband of any AM Broadcast receiver, as defined by the FCC. 

The bottom line is that a cw transmitter with power of 100 mW on a frequency of AM Broadcast channel plus five, would be legal according to current FCC rules. 

Modern receivers and rigs with modern CW filtering of 250 Hz passband would be able to pick up such signals nicely, filtering out the AM stations. 

So, my thoughts are that this situation would allow CW operation without a license, legally and according to FCC rules. 

Any thoughts, anyone?

 Undecided
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N4OI
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« Reply #38 on: August 24, 2017, 11:52:31 AM »

I'm wondering if those with children are forgetting that they can use your key and have fun on the radio, a great way for them to be excited in learning CW. Naturally it will help if they know some CW to start with, but you can also hold their hand. The only thing you need to do is supervise and operate the VFO and ensure the transmission is legal, e.g. ID every 10 minutes at least. But in between that they can use your TX. So I'm wondering if folks with kids with them have considered this and given it a try.

Ahh... this explains a lot of what I hear on the bands...  toddlers, I assume...

73
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WW7KE
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« Reply #39 on: August 24, 2017, 11:58:54 AM »

Roll Eyes
Another idea - just thinking and just saying - and I might be shot down for this idea.

The official FCC rules for the broadcast band (540-1710 KHz) state the limit for a transmitter is "100mW".  One hundred milliwatts. That is a significant amount of power, it may be heard over a few hundred meters away.  Of course this type of use must not interfere with licensed broadcasters, and must accept interference from licensed etc.

What about a cw transmitter for a frequency that is between station channels and is between stations that are in the "grave yard"?  So, between channels means that the channels in the US are all on a 10 KHz even number, e.g. 1270, 1280, 1290, 1300 KHz, etc.  My suggestion here would be a cw transmitter on the 5 KHz between two channels, such as 1275, 1285, 1295, 1305 etc.  and so on.  Also, these frequencies are called the graveyard because many stations are assigned each frequency.  Unless there is a local (within 50 miles) station, all you hear on these graveyard frequencies is many stations all interfering with each other.  You can't pick out any distinct station.  The FCC allows this for some reason known only to themselves.  Also, when a cw transmitter is on a frequency that is 5 KHz away from any other transmitter, the hetrodyne will be at 5000 Hz, which is outside of the passband of any AM Broadcast receiver, as defined by the FCC. 

The bottom line is that a cw transmitter with power of 100 mW on a frequency of AM Broadcast channel plus five, would be legal according to current FCC rules. 

Modern receivers and rigs with modern CW filtering of 250 Hz passband would be able to pick up such signals nicely, filtering out the AM stations. 

So, my thoughts are that this situation would allow CW operation without a license, legally and according to FCC rules. 

Any thoughts, anyone?

 Undecided

That's not a problem at all, as long as the power input is 100 mW or less, and the antenna is 3 meters.  The Part 15 rules don't mandate any mode, except for those sections designed for a specific use (wireless microphones, field disturbance sensors, etc).  You can even operate CW in the FM broadcast band, although I have no idea why anyone would want to, as long as the field strength is 250 uV/m at 3 meters (17 nanowatts EIRP).

I don't know how active they are these days, but these Part 15 hobbyists are called LOWFERS (160-190kHz), MEDFERS (AM broadcast, usually on 1610-1700 kHz), and HIFERS (13560 ± 7 kHz). 

IIRC, the CB channels can still be used as well, but not in the way the old 100 mW walkie-talkies operated, and not under Part 95.  The kiddie-talkies were moved to 49.82-49.9 MHz, which is also a general-use Part 15 band, in the 1980s.
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VK5EEE
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Posts: 939




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« Reply #40 on: August 24, 2017, 07:32:51 PM »

Yes 27000 +/- a large amount, I forget, would have to look it up... is also allowed many countries with higher power.

https://en.wikipedia.org/wiki/ISM_band

26.957 MHz to 27.283 MHz    Type B    center frequency 27.12 MHz    Worldwide    FIXED & MOBILE SERVICE except Aeronautical mobile service, and CB Radio

Type B (footnote 5.150) = frequency bands are also designated for ISM applications. Radiocommunication services operating within these bands must accept harmful interference which may be caused by these applications.

IN Australia "LIPD" Licensed Idiot Police Department? No, Low Interference Potential Devices. http://www.acma.gov.au/Industry/Spectrum/Radiocomms-licensing/Class-licences/lipd-class-licence-spectrum-acma

LIPDs operating in bands designated for industrial, scientific and medical (ISM) applications are not protected from interference caused by ISM applications (e.g. microwave ovens). The ISM bands are:

    13553-13567 kHz

    26957-27283 kHz

    40.66-40.70 MHz

    918-926 MHz

    2400-2500 MHz

    5725-5875 MHz

    24-24.25 GHz

Operating frequencies

The LIPD class licence authorises any person to operate a device that uses a frequency:

    on or within a range of frequencies, mentioned in column 3 of Schedule 1 of the LIPD class licence;

    at a radiated power that does not exceed the maximum EIRP mentioned in column 4 of Schedule 1 of the LIPD class licence;

    within any of the limitations mentioned in column 5 of Schedule 1 of the LIPD class licence.

PUNISHMENT

For exceeding the power limits per 1uV/km a fine of $10,478 dollars and jail time of 3 years, revocation of driving license.

Here is the license:

https://www.legislation.gov.au/Series/F2015L01438

Nothing allowed in the AM broadcast band in Australia. Someone might broadcast a message of insurrection that could be heard by 2 or 3 neighbors. But, among other things, allowed are:

All transmitters: 13.553–13.567MHz 100 mW you can go far with 100mW on CW and the band there is quiet. But that is probably 100mW EIRP relating to some theoretical bureaucrat antenna, so a dipole may allow you a lot less. I did not research the endless foot notes.

Quite promising is All transmitters 26.957–27.283MHz 1 W yes that is one Mega Milli Watt of Power!!!! subject to:
   

(a)    Separation of the operating frequency from the centre frequency of any adjacent citizen band radio channel must be at least 5 kHz.

(b)   The emission bandwidth must not exceed 10 kHz.

One can go quite far there on 1W on ground wave, and in many years time, perhaps, around the world. 27000kHz meets that requirement and Xtals for that frequency are easily available.

But one around the 13.56 MHz would seem more useful, and I wonder if the punishments for exceeding the 0.1 Watt are noticed, or enforced. One could always try to plead ignorance on the first offense, given the regulations are so complicated and you could not afford a liar lawyer to interpret them.
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Long Live Real Human CW and wishing you many happy CW QSO - 77 - CW Forever
WW7KE
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« Reply #41 on: August 24, 2017, 08:24:24 PM »

Interesting that Australia allows higher power on 13.56 and CB, but nothing on AM.

The American general-purpose Part 15 bands (outside the general radiation limits of 47 CFR 15.209) are:

§15.217:  160-190 kHz -- 1 watt input, 15 meter antenna/feedline/ground length.
§15.219:  510-1700 kHz -- 100 mW input, 3 meter antenna/feedline/ground length.

§15.225 defines the following, mostly used for RFID tags, but modes are not specified, so anything goes:
13.110-13.410 MHz -- 106 uV/m at 30 meters, or roughly 337 nW EIRP
13.410-13.553 MHz -- 334 uV/m at 30 meters, or roughly 3.3 uW EIRP
13.553-13.567 MHz -- 15,848 uV/m at 30 meters, or roughly 7.5 mW EIRP.
13.567-13.710 MHz -- 334 uV/m at 30 meters, or roughly 3.3 uW EIRP
13.710-14.010 MHz -- 106 uV/m at 30 meters, or roughly 337 nW EIRP (yeah, try that in the 20m Extra band. Grin )

§15.227:  26.96-27.28 MHz (CB) -- 10,000 uV/m at 3 meters, or roughly 30 uW EIRP.  100 mW kiddie-talkies are no longer authorized.
§15.229:  40.66-40.70 MHz:  1000 uV at 3 meters, or roughly 300 nW EIRP.
§15.235:  49.82-49.90 MHz:  10,000 uV/m at 3 meters, or 100 mW input with a one meter single-element antenna.
§15.239:  88-108 MHz:  250 uV/m at 3 meters, or 17 nW EIRP.  Bandwidth must be 200 kHz maximum.

§15.249: 
902-928, 2400-2483.5, 5725-5875 MHz:  50 mV/m at 3 meters, or roughly 0.75 mW EIRP.
24.0-24.25 MHz:  250 mV/m at 3 meters, or roughly 19 mW EIRP.

The transmission mode is not specified under any of these FCC regulations.

IIRC, Canada also allows their equivalent of Part 15 in the ISM 6780 kHz band, but I don't know the power and/or field strength limits.  This is not authorized in the US.
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HB9FXW
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Posts: 48




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« Reply #42 on: August 24, 2017, 10:43:49 PM »

Here in Switzerland it's illegal to let any unlicensed person to operate your rig, unless for a public event but then you need to notify the autorities 2 weeks prior.

Quite promising is All transmitters 26.957–27.283MHz 1 W yes that is one Mega Milli Watt of Power!!!!

I wish my QRP rig had five of those mega-milliwatts, but unfortunately it only has kilo-milliwatts.  Wink
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VK5EEE
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« Reply #43 on: August 24, 2017, 11:51:32 PM »

I wish my QRP rig had five of those mega-milliwatts, but unfortunately it only has kilo-milliwatts.  Wink
Oh yes, so does mine  Angry I measured the power wrongly  Roll Eyes thanks for alerting me!
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Long Live Real Human CW and wishing you many happy CW QSO - 77 - CW Forever
N4RSS
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« Reply #44 on: August 25, 2017, 07:38:07 AM »



OET bulletin 63 has this:

Although the precise relationship between power and field strength can depend on a number of additional factors, a commonly-used equation to approximate their relationship is:

((P * G) / (4 * pi * D^2)) = ((E^2) / (120 * pi))

P is transmitter power in Watts
G is the numerical gain of the transmitting antenna relative to an isotropic source
D is the distance of the measuring point from the electrical center of the antenna in meters
E is field strength in volts/meter.

120 * pi, or 376.9, is the impedance of free space in ohms

30 uV/m at 30 meters is roughly 27 nanowatts EIRP (G=1).  The calculation is frequency-independent.


It can be fun to see how far dimensional analysis can get you.  Not being familiar with the above equation I pursued the following.  Mixed some fundamental units with derived ones for convenience sake:

Power [energy/time] = Field strength [energy/charge-length]^2 multiplied by "X"
                                  whose dimensions force dimensions of power on the left

"X" therefore has dimensions [charge]^2 x [Length]^2/[energy] x [time]

[Length]^2 is area, 4piD^2 pretty obviously, area of sphere

[charge]^2/[energy][time] is the inverse of impedance in ohms as we know, which equals 120pi for free space

Therefore, Power/[(4piD^2) = (Field strength, E)^2/120pi

Consider a unitless gain factor on the left if other than 1

« Last Edit: August 25, 2017, 07:40:25 AM by N4RSS » Logged
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