Though they have their own share of problems just as AM or FM they do have the un-canny ability to be heard in the most adverse environments.
CW is often the choice for beacons used for aviation, ham radio, part 15 LW and in some cases 11 meter beacons. Maritime beacons are often Morse code programmed into a digital chip much like the one built in to the Talking House.Some beacons are more sophisticated and use a type of telemetry to send important oceanic readings back to NOAA via satellite or land based stations.
SSB is my second home when operating a cb radio because it can be heard for 1000's of miles and in most cases a voice on ssb can be pulled in when many stations are piled up on one frequency.
SSB of course is all audio but is only good for voice because of the narrow bandwidth the SSB signals occupy. If i was going to operate in the 1750 meter band as a part 15 station i think it would be AM or FM. And yes FM can be used there but i am not sure what the audio quality would be like down there. I imagine you can add a c-quam encoder and transmit in am stereo.??
This is a great idea and a great group project.
Though they have their own share of problems just as AM or FM they do have the un-canny ability to be heard in the most adverse environments.
CW is often the choice for beacons used for aviation, ham radio, part 15 LW and in some cases 11 meter beacons. Maritime beacons are often Morse code programmed into a digital chip much like the one built in to the Talking House.Some beacons are more sophisticated and use a type of telemetry to send important oceanic readings back to NOAA via satellite or land based stations.
SSB is my second home when operating a cb radio because it can be heard for 1000's of miles and in most cases a voice on ssb can be pulled in when many stations are piled up on one frequency.
SSB of course is all audio but is only good for voice because of the narrow bandwidth the SSB signals occupy. If i was going to operate in the 1750 meter band as a part 15 station i think it would be AM or FM. And yes FM can be used there but i am not sure what the audio quality would be like down there. I imagine you can add a c-quam encoder and transmit in am stereo.??
This is a great idea and a great group project.
"I imagine you can add a c-quam encoder and transmit in am stereo.??"
Sure..why not. All that would be needed on the receiver is adapting a decoder to a receiver, such as the ASPiSYS AM C-QUAM decoder board.
http://www.aspisys.com/dqam.htm
Also ASPiSYS can adapt the ASMAX-1 TX unit to transmit on the LW band. Simply request them to gear it up for LW when ordering.
http://www.aspisys.com/ampll.htm
Can do the same for a LW station operating in FM mode. Add a stereo encoder to the TX, add a FM stereo decoder to the receiver (same IF connection point as the AM C-QUAM decoder) and you got LW FM Stereo.
RFB
"Forget about AM or SSB. Slow speed Morse code is the mode for Lowfers."
Modulation methods are only limited by the experimenter's will to be weird.
A lot can be learned by examining what is being done in the Lowfer arena. However what Lowfer's are doing today does not mean other methods are impossible.
The endeavor here is not trying to establish 1000 mile distant contacts, or shoot for the most efficiency in the transmitter through modulation or operation modes.
The goal here is to put something on the LW band that the general public will be able to pick up besides buzzes and noises and digital hashes or blips and bleeps of Morse code.
If we can achieve local coverage (and even at 1W A3E a LW signal will cover far more range than a 100mW MW can) for all those radios on the wally world and rad shack shelves built to pick up the LW band in AM mode, the effort will be worthwhile.
The general public will not bother wasting time tuning into a band of radio where nothing but a band of noises and buzzes and beeps are found. But put something there that they can recognize..like regular audio..be it music or voice, that will get their attention real quick. With a little bit of proper campaigning, public awareness to the "Lost Band", and by providing something more than just clicks and pops and whistling buzz bops, then perhaps that "Lost Band" won't be so lost after all.
The FCC rules specify "ANY" in the mode of operation for the 160-190Khz Part 15 band. That means we are not limited to the type of operating mode just because traditionally the "Lowefer's" operate in CW. The "Lowefer" concept is to DX communications as far as possible with the lowest power possible.
I do not knock what Lowfer's do. Their operations are specific and for a specific purpose. This LW endeavor has its own purpose and goal as well. And the goal and purpose cannot be achieved by setting up this LW network as nothing more than more noises, bleeps and pops. What would be the point?
If AM was not a viable means of transmission on the LW band, then all those European stations currently operating A3E in the LW band would not exist...despite their mega watt power range vs our mere 1W power limit.
As to having the real estate for a ground radial system, well one may not have enough, but then again that does not mean that another won't. Heck current MW setups do not have enough real estate either..not when a typical MW setup requires at least 120, 120 foot long radials, yet Part 15 setups in the MW band are doing just fine with what they CAN set up in what space they do have...same can be applied to the LW setup.
Again..it is a matter of willingness to experiment and discover what will work and what will not work...just like the MW band or any other band.
If we all stuck with tradition...we would still be running around in cloth robes and going to town in horse drawn buggies sending messages via pigeon express and in floating bottles.
If there is something to be forgotten about...I say lets forget tradition and start doing. Nothing done is nothing gained.
RFB
In the spirit posed by RFB in his great pep talk, please know, one and all, that KDX plans to go AM on the LW band. That is the deal.
HOWEVER, in the future we might play other games.
We might try SSB, or STEREO or CW or .... other or.
My old friend Percy Downer puts it this way, "Why do it?"
That may not be the best person to quote, but I'm going to do it!
A great idea Carl! The LW network stations can also setup other operations using CW or SSB or digital in the LW band as expansions to the network as a whole.
Why not!
That is what I mean by willingness to be weird in this hobby. The limits are only set by the limits put on imagination.
RFB
To demonstrate the potential, I offer a sample sound file (mp3 format) of a recent test of my LW transmitter design operating in A3E mode on 180Khz at 1W into the Motorola R 2012 D analyzer and its internal 50 ohm dummy load.
The audio was recorded from a portable battery powered radio (MXC Crown CR28/SN 16328) placed near the transmitter. Audio is then taken from the earphone jack into the line input on my station's audio production computer running Adobe Audition 1.5 as the sampling program in WAV format.
Tuning begins at 150Khz at a slow but steady rate (manual tuning) and reaches the LW test frequency at 180KHz. We then get to hear just how good LW AM sounds..even from an inexpensive receiver...in mono! (Mode A3E @ 76%)
http://krocksradioone.com/files/K_ROCKS_LWSAMPLE1_180KHZ_128kps.mp3
http://krocksradioone.com/files/K_ROCKS_LWSAMPLE1_180KHZ_320kps.mp3
Enjoy.
RFB
That sounds REALLY good!
So you cooked up an LWBC
test transmitter already?
I was thinking of getting
a Ramsey AM-1C, building it
for 540, and just changing the
caps or coils to go down from
there. That would also get a
test signal going. And the AM-1C
is only 35 or 40 dollars. I
think there is a way to increase
the power of that circuit.
I'm just looking at it for the sheer
fun of trying it.
(I am still working on the 13.560 rig.)
Bruce,
Dog Radio Studio 2
"So you cooked up an LWBC
test transmitter already?"
Yep. All still on the breadboard and far from the final prototype.
Not a bad idea to take a Ramsay AM-1C and modify it for LW.
RFB
"That sounds REALLY good!"
It does! And the sample is of voice with low music background.
The next sample is of music content. Same test conditions and equipment as the first sample. Except this time I turned the tuning knob a bit faster from 150Khz to the test frequency at 180Khz.
http://krocksradioone.com/files/K_ROCKS_LWSAMPLE2_180KHZ_128kps.mp3
http://krocksradioone.com/files/K_ROCKS_LWSAMPLE2_180KHZ_320kps.mp3
RFB
The LW AM samples are excellent demonstrations and indeed reveal the quality achievable on low frequency.
Before I logged in and heard those examples, I was having a thought that relates very closely to the discussion...
I suggest that, for purposes of extending the reach of an AM signal on a long wave channel, one could do the following:
1.) roll-off the signal below 200Hz because the low frequencies consume large amounts of available energy and dynamic range;
2.) roll-off frequencies above 4kHz because the upper frequencies eat up bandwidth and lower over-all modulation;
3.) put a 5dB peak around 2.5kHz;
3.) drive the sound hard by limiting tightly at the upper level;
4.) compress to bring up quieter signals above the noise-floor;
5.) mono.
This could be described as a voice response curve similar to that used on the telephone network for speech clarity.
In essence, only "intelligible and intelligent" information utilizes the modulation energy, and the loudness and sharpness of the signal would penetrate noise and distance.
Gentlemen?
This morning I am conducting a study-review of the Rules for unlicensed long wave.
15.209 9kHz to 490kHz 2400uV/V @ 300m
15.217 160kHz to 190kHz 1W to final 15m antenna
Getting familiar with the terrain.
The other day I posted the long wave bandwidth covered by my Sangeon and Transoceanic radios, and today I remembered the little Alinco communications receiver, and it is very wide and long in the channels covered:
100kHz to 515kHz in 5kHz increments.
Oh boy.
"I suggest that, for purposes of extending the reach of an AM signal on a long wave channel, one could do the following....
This could be described as a voice response curve similar to that used on the telephone network for speech clarity."
Do not see any reason not to try those suggestions. After all, its all about experimenting!
RFB
160-190 kHz
Cable locating equipment 1 Watt peak
output power
15.213
Any 1 Watt input to final RF
stage
15.217
Any 2400/f(kHz)
μV/m @ 300 m
A 15.209 (A means the type of detector used to make the measurement....Average peak. Q is Quasi-Peak.
The word "Any" describes the mode of operation..ie AM/FM/CW/FSK etc.
2400/180khz = 13.33 μV/m @ 300m which is 984 feet, 3.02 inches from antenna.
Just a bit lower μV/m for MW @ 30m which is 24000/f μV/m @ 30m. 24000/1670 = 14.37125 μV/m @ 30m which is 98' 5.10" (15.209 Q) NOTE: Frequency used is the K-ROCKS AM station on 1670Khz.
15.221-Q (CC) is about the same as well. 47715/1670 = 28.578m for 15 μV/m which is 91' 10.36". NOTE: Frequency used is the K-ROCKS AM station on 1670Khz.
Taken from the trusty dusty FCC Part 15 Handbook OET publication #63. Any errors report them to the appropriate formula gurus at the FCC and Texas Instruments (maker of calculator).
RFB