On 6/29/2016 12:19 PM, Jeff Liebermann wrote:
On Wed, 29 Jun 2016 11:29:12 -0400, rickman wrote:

Mostly yet.

That should be "yes". In a hurry today (like all other days).

However, some bands do not require a license and operate
under FCC Part 15:
http://www.lwca.org
https://en.wikipedia.org/wiki/LowFER
http://www.arrl.org/lf-low-frequency
https://hackaday.io/project/6882-lowfer-transmitter-for-your-arduino
etc...

Very interesting. I see a difference between the ARRL article and the
Hackaday page. ARRL says the power limit on the US 1750 meter "free
band" is 1 W into the "transmitter's final stage" while the Hackaday
page says the limit is 1 W into the "feedline" and antenna system.

This might help:
http://www.lwca.org/sitepage/part15/index-what.htm
http://lwca.org/library/reference/
Note that it's a bit out of date. Adjust the links for 2016.
You want part 15.217 (Operation in the band 160-190 kHz.)
http://www.ka7oei.com/ct_lowfer_archive.html

I see that kind of stuff quite a bit in the FCC rules-n-regs. They
sometimes fail to specify WHERE the transmit power is to be measured.
Is it at the input to the xmitter, output of the xmitter or at the end
of a lossy feed line. What does one do if the system is not 50 ohms?
I don't have an answer and since the FCC never will admit to making a
mistake, it's unlikely to be fixed. Should you ask for clarification,
you'll probably get an answer from the FCC which you don't want to
hear. Been there, many times. My best advice is do your best with
what you have, don't try to play FCC attorney, and muddle onward into
the unknown.

Thanks for the links. I found 15.217 and it says,

15.217 Operation in the band 160–190 kHz.
(a) The total input power to the final
radio frequency stage (exclusive of fila-
ment or heater power) shall not exceed
one watt.

Since they specifically exclude the filament power I supposed that 1
watt limit is on the power from the supply rather than the "input" power
to the grid/base/gate of the active element. So in reality the 1 watt
limit at the input to the final stage will produce less than 1 watt at
the output of the final stage.

With the frequency being so low, a class D output could potentially
provide nearly the full watt to the feedline I expect. Some amount of
filtering would be needed to prevent the carrier from making it out the
antenna, but using sigma-delta techniques should help to minimize that.

With such low power and simple output stage, it could be placed at the
antenna which would allow the full 15 meters to be antenna.

--

Rick C

On Wed, 29 Jun 2016 12:53:28 -0400, rickman wrote:

I'm back from the dentist drilling holes in my teeth and bank account.

Thanks for the links. I found 15.217 and it says,

15.217 Operation in the band 160–190 kHz.
(a) The total input power to the final
radio frequency stage (exclusive of fila-
ment or heater power) shall not exceed
one watt.

Yep, that's it.

Since they specifically exclude the filament power I supposed that 1
watt limit is on the power from the supply rather than the "input" power
to the grid/base/gate of the active element. So in reality the 1 watt
limit at the input to the final stage will produce less than 1 watt at
the output of the final stage.

With the frequency being so low, a class D output could potentially
provide nearly the full watt to the feedline I expect. Some amount of
filtering would be needed to prevent the carrier from making it out the
antenna, but using sigma-delta techniques should help to minimize that.

Yep, except why bother with an amplifier? You could just modulate a
200Khz switching power supply and get similar results. Lots of other
options available, but few of them involve a traditional amplifier
multiplier chain.

With such low power and simple output stage, it could be placed at the
antenna which would allow the full 15 meters to be antenna.

Any way you look at it, it's going to be flea power buried under tons
of atmospheric noise. Everything you do up to about 300 meters range
is near field.
http://www.part15.us/forum/part15-forums/general-discussion/part-15-am-communications-near-field
http://www.part15.us/forum/part15-forums/general-discussion/longwave-broadcast-dx-171-khz

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

On Wed, 29 Jun 2016 07:59:51 -0700, Jeff Liebermann
wrote:

I have been looking into design of receivers in the LF to ELF frequency
ranges. Is this part of "amateur" radio?

Mostly yet. However, some bands do not require a license and operate
under FCC Part 15:

I forgot to mumble something about which bands require an amateur
license and which do not under Part 15. The lowest frequency band
that requires a ham license is 160 meters (1.8 to 2.0 MHz).
http://www.arrl.org/frequency-allocations
The various bands below that fall under Part 15.xxx as intentional
radiator rules and do NOT require a license. However, 135.7 to
137.8Khz (2200 meters) is designated as an amateur radio band by the
ITU. However, since it more easily falls under unlicensed Part 15
rules, the FCC does not require an amateur license to operate there.
These bands are not world wide and vary by national jurisdiction:
https://en.wikipedia.org/wiki/LowFER
https://en.wikipedia.org/wiki/2200-meter_band

Most LOWFER experimenters have ham radio call signs and use them on
the LOWFER frequencies. There is no requirement to identify with an
amateur call sign, but it is convenient.


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

"rickman" wrote in message ...

The term "amateur" is often applied to people who have obtained a
license to use radio equipment for communications. Is this term
inclusive of those who don't obtain a license but use receivers for
various uses?

I have been looking into design of receivers in the LF to ELF frequency
ranges. Is this part of "amateur" radio?

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

I would say no. Can we term such people radio experimenters, please?

There are certainly radio experimenters who neither need or want to hold
licenses to use the amateur bands and I have NO objection to their choice
of what they want to build and try. I think the folks who hold ham licenses
can legitimately lay claim to the moniker "radio amateur."

I wish language had the same certainties as, say, physics. It doesn't.
Language has wiggle room and we're stuck with it.

"Sal"

"rickman" wrote in message ...

The term "amateur" is often applied to people who have obtained a license
to use radio equipment for communications. Is this term inclusive of those
who don't obtain a license but use receivers for various uses?

I have been looking into design of receivers in the LF to ELF frequency
ranges. Is this part of "amateur" radio?

No.
My understanding of "amateur radio" is having a license to transmit on
"amateur" bands.
Receiving, studying receivers, building receivers, etc. does not require a
license....at least in civilized countries

On Saturday, July 2, 2016 at 6:05:19 PM UTC+10, Wayne wrote:
"rickman" wrote in message ...

The term "amateur" is often applied to people who have obtained a license
to use radio equipment for communications. Is this term inclusive of those
who don't obtain a license but use receivers for various uses?

I have been looking into design of receivers in the LF to ELF frequency
ranges. Is this part of "amateur" radio?

No.
My understanding of "amateur radio" is having a license to transmit on
"amateur" bands.
Receiving, studying receivers, building receivers, etc. does not require a
license....at least in civilized countries

That makes you an SWL.

On Thu, 30 Jun 2016, Jeff wrote:


I forgot to mumble something about which bands require an amateur
license and which do not under Part 15. The lowest frequency band
that requires a ham license is 160 meters (1.8 to 2.0 MHz).
http://www.arrl.org/frequency-allocations

That of course depends on which country you live in.

In the UK 137kHz is an band that requires an amateur licence, with a power
limit of 1W ERP (a significant difference to 1W into the PA stage)!!

427 to 479kHz is also an amateur band in the UK with a 5W erp limit

I think the US is a tad behind, but that may have already changed.

Here in Canada we definitely have one of the new LF bands, but I can't
remember the details.

As long ago as WARC 79 there was talk of making that low frequency license
free band a ham band, so finally that's come to fruition, more or less.

Michael

On Tue, 28 Jun 2016, rickman wrote:

The term "amateur" is often applied to people who have obtained a license to
use radio equipment for communications. Is this term inclusive of those who
don't obtain a license but use receivers for various uses?

I have been looking into design of receivers in the LF to ELF frequency
ranges. Is this part of "amateur" radio?

It's complicated.

One reason amateur radio exists is because once Marconi spanned the
Atlantic with radio, it was out of the lab and people played with it.
There was a time when daily newspapers would have articles about it, so i
gather.

INitially, nobody had a use for radio, that came through use. So when the
Titanic sunk in 1912, the rules were tightened and then later tightended
more. Amateur radio was there from the start, the rules getting tighter
as the years progressed.

So you didn't need a license at first, and then later people started
broadcasting because they were aware more people were playing with radio
receivers than actually had transmitters.

There probably was no distinction initially, but as time went on, yes
"amateur radio" does mean a licensed ham radio operator.

There are people who have similar interests, but not in transmitting (or
they don't want to bother with the license), they are "amateurs" but not
"amateur radio operators" or whatever you want to call them. SOme have
mentioned shortwave listeners, and a subset of that is interested in
building, but I think most SWLers are just interested in receiving, maybe
building small projects to enhance reception.

SOmeone brought up part 15. That may be a grey area. 100mW walkie
talkies on the CB band were part 15, and in the sixties there were even
projects (and commercial units) for improving performance, "you can DX so
long as you keep within the rules", unlike CB that was only intended for
local communication. So those would place the transmitter and integral
antenna up a tower, and then use a decent shortwave receiver for
reception. That gave you height, but the better receiver probably helped
a lot, since those 100mW walkie talkies generally used superregenerative
receivers.

But that wouldn't have classified as "amateur radio".

And in the sixties and seventies there were articles in the hobby
magazines about that 160 to 190KHz band, promoting it as a hobby. Every
few years there'd be an article, often a construction article, but then
nothing. I think it was the late seventies when we'd start to hear about
serious work on that band, though perhaps it just wasn't visible before.
But as someone said, often by hams who were interested in using those low
frequencies. But the users of that band would be called "radio
hobbyists" even though the more serious users probably did have ham
licenses.

Michael

Michael Black wrote:
On Thu, 30 Jun 2016, Jeff wrote:


I forgot to mumble something about which bands require an amateur
license and which do not under Part 15. The lowest frequency band
that requires a ham license is 160 meters (1.8 to 2.0 MHz).
http://www.arrl.org/frequency-allocations

That of course depends on which country you live in.

In the UK 137kHz is an band that requires an amateur licence, with a power
limit of 1W ERP (a significant difference to 1W into the PA stage)!!

427 to 479kHz is also an amateur band in the UK with a 5W erp limit

I think the US is a tad behind, but that may have already changed.

Here in Canada we definitely have one of the new LF bands, but I can't
remember the details.

As long ago as WARC 79 there was talk of making that low frequency license
free band a ham band, so finally that's come to fruition, more or less.

Here in the Netherlands amateur radio licenses have been scrapped some
ten years ago. We have no licenses anymore. The amateur bands are
now all "license free bands with obligatory registration", like
maritime VHF radio. You just apply for a callsign and away you go,
without license.

To apply for a callsign you still need to pass an exam, just like with
maritime VHF. So to the outsider the system may look the same. And
in fact, many amateurs still talk about "the license". But there isn't
any.

Rob wrote:

Michael Black wrote:
On Thu, 30 Jun 2016, Jeff wrote:


I forgot to mumble something about which bands require an amateur
license and which do not under Part 15. The lowest frequency band
that requires a ham license is 160 meters (1.8 to 2.0 MHz).
http://www.arrl.org/frequency-allocations

That of course depends on which country you live in.

In the UK 137kHz is an band that requires an amateur licence, with a power
limit of 1W ERP (a significant difference to 1W into the PA stage)!!

427 to 479kHz is also an amateur band in the UK with a 5W erp limit

I think the US is a tad behind, but that may have already changed.

Here in Canada we definitely have one of the new LF bands, but I can't
remember the details.

As long ago as WARC 79 there was talk of making that low frequency license
free band a ham band, so finally that's come to fruition, more or less.

Here in the Netherlands amateur radio licenses have been scrapped some
ten years ago. We have no licenses anymore. The amateur bands are
now all "license free bands with obligatory registration", like
maritime VHF radio. You just apply for a callsign and away you go,
without license.

To apply for a callsign you still need to pass an exam, just like with
maritime VHF. So to the outsider the system may look the same. And
in fact, many amateurs still talk about "the license". But there isn't
any.

Does that mean anyone in the Netherllands can transmit on amateur
frequencies provided they don't a callsign that sounds like an amateur
one?
--

Roger Hayter