I've learned more in this Part 15 game than in
41 years of ham radio.
I wish you well.
Bruce,
DOGGRADIO STUDIO 2
My carrier current station is on hold awaiting parts, so I have begun scrolling through this very interesting thread because I have not given up on the long wave idea.
Something I found is this, a declaration from RFB:
"I am going to build a LW TX. It will use a PLL circuit with reference crystal controlling an oscillator, probably a Colpits design, followed by a two stage buffer. Then flow into a balanced modulator chip with selectable carrier or carrier null to facilitate AM and SSB. For the FM, there will be the typical direct FM configuration via the infamous varactor diode. When not operating in FM mode, the varactor circuit will simply be bypassed with a DIP package relay."
Since that time you have reported actually running a LW transmitter, so we would like an update on what you have built and whether it will be placed into the public domain for our snooping.
BUT, it is your right to hold the invention as proprietary information, in which case we will simply remain envious and curious.
"we would like an update on what you have built and whether it will be placed into the public domain for our snooping."
When it's done. :p
RFB
The Deep Voice Long Wave Transmitter Project remains unfinished and I am considering taking a short cut and purchasing an AM88 so I can bring a long wave signal to the air.
However, not being the only member of the National Longwave Network I will keep the Deep Voice Web Page active and follow any activity on these threads regarding longwave development.
Great Ken, nice batch of links for low power.
That 10-gallon loading coil looks like something for giants.
Long wave could be renamed giganto-wave, just the opposite of micro-wave.
Carl, I suggest you hold off on getting
anything for longwave. I really think
you are heading in the right direction
with what you have.
And Why don't we see if RFB is able to show
us his unit when he's done. (No pressure,
RFB.)
By the way, some of those links were mind
blowing. I can't believe those coils and
variometers!
bruce, DRS2
I'm not sure why Doggradio Studio 2 would advise against investing in long wave at this time, but what's interesting is that he is so right.
Before putting the AM88 transmitter on the credit card, I made one last reading of the Specs and Features. Some problems jumped out.
Think about this:
Medium Wave Power Out AM Mode: 100mW max (2000kHz)
My Comment: If that is true, then the transmitter is illegal. Do you understand why? But that only applies to the medium wave use of the transmitter, and I want to use it's long wave feature.
Long Wave Power Out AM Mode: 200mW (150 kHz) into 50 ohms.
My Comment: Let's assume that is true. It would mean the transmitter is only 20% efficient. Are you interpreting it the way I am?
Order is canceled. Doggradio Studio 2 gives good advice.
Well, I knew there was something lacking
regarding the AM88's longwave capability,
but I think the guys at North Country Radio
are very good people and I think they have
a great company.
Here's the thing. I think the AM88 is really
intended for the AM broadcast band. This
is just my opinion - however there may be
some truth to it. AND, It is my belief (or theory)
that the 100 mW AM BCB OUTPUT SPEC is a
typo. These guy are very very smart, and I
think they just goofed. (This is just my theory,
of course.)
The AM88 AM transmitter and the MPX96 FM
transmitter (I own an MPX-96) began as construction
articles in a very well known electronics magazine.
I think the magazine might have been Popular Electronics,
but I'm not sure. it was years ago, anyway.
(This may have fostered the beginnings of North
Country Radio at that time.)
As far as I can remember from the original article,
the AM88 article stated that it was for the AM BCB.
And if I am not wrong about this, I think the LW
capability is a secondary "gift" that the AM88 provides.
It will operate down there, but just not at the full power
allowed by Part 15 at 160 to 190 kHz.
(Again, this is just my brain talking.) I understand the
AM88 is VERY GOOD on the AM BCB and that it's
audio is first rate!
As we know, most experimenters down on 160 to 190 kHz
are using digital formats from old Morse code up to
the most advanced experimental digital protocols that
exist today. I have heard stories about Part 15 operations
that ARE using voice down there, but I believe this
is very rare. I think some of these AM LW experiments
are just yard casting. And if you have a nice antique radio
collection, yard casting on your property can be fun
just by itself. And here are some old radios that tune LW.
I know - I have a 50 year old radio that is pretty good
down on LW.
So - the AM88 doesn't do Part 15 full power(?) or modulation(?)
down at 160 to 190 khz...
(I'll take a look at this, too.)
So I think this is why North Country Radio came out
with it's LF-90, which is a Morse code transmitter for
the 160 to 190 range, which runs I watt DC input to
the final. It's just Morse code, but that's really where
you have to start, I think.
If I had the land and the money, I would get an LF-90
and North Country Radio's LF receiving converter in
a minute! I have always wanted to operate down there,
even if just with a Morse code beacon.
I believe what RFB is fabricating is a different kind of
transmitter. I believe, with the right parts and adjustments,
his version could operate at many different modes, such
as AM, cw, ssb, and maybe even something like QRSS or
PSK31. (QRSS and PSK31 are some digital modes that
i know a little about, but not much. There is so much
interesting work being done with the digital modes.)
So, if I'm correct, RFB is fabricating a low power section
that can generate these many modes, and then he plans to
employ a linear amp to get things up to the 1 watt area.
I know that there has been successful experimentation
on the west coast with 160 - 190 ssb - I have read about it.
Anyway, that's what I think RFB is doing. I have no doubt
that he will prevail, but he is very busy, and it might take
him a while.
So this is what I think, anyway. I think North Country Radio
is a wonderful company. But if it was me, I would get an
LF-90 transmitter, get it going with Morse code, and then
try to modulate it. I remember RFB stating that this is
possible.
So that's it from here.
Best Wishes,
Bruce, DRS2
P.S. Maybe I'll save up for North Country Radio's
receiving converter, and then go for an LF-90
after that. It will take a while, but maybe, for me,
that is the way to go!
P.P.S. The specs for the AM-88 that you mentioned
above, Carl, were 100 mW out at 2000 kHz. Well,
that's the top of the 160 meter ham band. If you
own a ham license, there is nothing illegal about
that (except that you meed to be below 2000 kHz
to really be in the ham band, you know - like 1990 kHz
so the upper sideband doesn't get out of the band.
Perhaps the DC input of the transmitter is adjustable. -Bruce
The AM88 has one other spec that should be mentioned.
CW or FM Power Output up to 1 Watt at lower frequencies.
But my main goal is to run AM audio programming.
I am going to complete work on Deep Voice, all it needs is the oscillator.
I might combine some audio recordings of Morse code as a kind of CW, but what will it say? KDX does not run station I.D. because we are not required to do so.
Maybe the code could say stuff like, "Hi. How ya doing?"
Hi Carl!
The longwave beacon guys do just
about any identifier that they want.
25 years ago, my local BC engineering
friend was running a beacon on longwave
part 15 at 189 kHz. This was running
straight cw. He also ran a 100 mW cw
beacon on 1625 kHz. It was heard out
to about 100 miles also.
He used his name and also gave out his
address for QSL info. I believe his
beacon got out about 100 miles. (Since
I was once a graphics artist, I designed
his QSL card. There's still a copy of
it around here somewhere.)
The LW Part 15 beacon I heard on my FRG-7700
in West Hartford in about 1982, simply identified
itself as SD. The frequency and identifier were
on the published lists from the Long Wave Club of
America (a wonderful club, by the way) so everybody
who heard SD knew where to send their monitoring info.
You could just use C A R L - if you wanted to. You
could even do it as true cw - just on/off carrier
at the top of the hour. but that would require some
work to figure out how to do that.
If you use an audio tone on the carrier for
your ID, I would recommend a fairly high pitch
that gets through the noise. This is what
AM BCB stations do for scheduled DX tests. And
it works.
I hope that's helpful.
Best Wishes,
Bruce, DRS2
P.S. The radio rumor mill says that
somebody's 13.560 MHz (approx) beacon
went 7000 miles recently. However, before
you laugh and fall off of your chair, I
can tell you that I believe it.
Some of these "13.560" beacons are running
special digital modes. The evidence that this
beacon made it 7000 miles to the receiving point
is the graphic trace on a computerized software
driven receiver. I saw a picture of it on one of
the links that was posted on this thread. That's
why I had mentioned that, someday, I might hear
your 13.560 MHz carrier here. It is possible.
The audio would be too weak, though.
But this is the wrong thread for that. -Bruce
For awhile I thought that "CW" stood for "continuous wave", but that wouldn't fit what it actually means. The "C" might stand for "Code" but what does "W" mean? Maybe it means "Code What".
Anyway, you bring up a point that I bring up: how can the "on off" keying that actually distinquishes CW be accomplished automatically, which I assume the beacon stations require in order to operate constantly. Surely the HAM is not sitting there personally keying the beacon all day and all night. That would be more insane than operating a part 15 station with perfect programming that goes 200 feet.
A really smart automation system should be able to cut and restore the carrier or switch transmitters in addition to merely running audio playlists, but do any of them do that? Perhaps we should invent a way of doing that.
Would it count if the announcer simply voiced "dash-dash-dit-dit..."
If the announcer voiced the morse code it would be MCW.
From Wiki:
"Simply put, MCW uses a fixed audio tone to modulate a carrier wave. This is an older method of sending Morse code, with continuous wave being the more common method used today.
Unlike A1A CW transmissions, A2A MCW morse can clearly be heard on a normal AM radio receiver. It was commonly used by many RDF beacons to send a morse station identifier on a regular basis.
MCW is not allowed in the United States on amateur radio frequencies lower than 50.1 MHz, as it is a very inefficient use of radio spectrum."
A2A, or modulated continuous wave,
gets used by AM radio stations
that are participating in DX tests.
The carrier is always running, and
you can hear the audio Morse code
(MCW) through all of the noise and
interference. AM DX listening clubs
still do this. They will arrange for
at station to go on during the test
time, very often on the day pattern,
and the station will play announcements
and MCW. Then a bunch of AM DXers
might be able to log a state they never
would have heard otherwise.
CW is continuous wave, which doesn't
really make sense - but it refers to
a carrier wave (which is keyed on and off.)
They named it continuous wave because it
came along after spark gap transmitting,
which wasn't a carrier, it was just a keyed
spark that went out to the transmitting antenna.
Bruce, DRS2
Spark gap transmitters produce a damped waveform.
With each spark the tuned LC circuit is "shocked" into oscillation. Like striking a bell there is the initial large output which dies (damps) out until the next "shock".
CW, continuous wave oscillators, on the other hand produce a steady unmodulated RF waveform. Intelligence is impressed on the continuous wave by interrupting it but the output power is constant rather than damping out repetitively.
Now, a rotary spark gap transmitter does produce a specific audio tone due to the fact that the damped wave is occuring at a repetitive audio rate. The stationary spark gap transmitter produces a more random noise (buzz) as the spark does not occur at a specific repetition.