Carl, you mentioned WHA, in Madison, WI.
Again, one of those last three letter callsigns.
I suppose it's possible they left their daytime
power on by mistake - sometimes that happens.
But if the signal sounded fairly weak, then maybe
it really was the lower power - what was that -
51 watts?
I have heard quite a few stations that are listed
as very low power at night. Some of them sound
like they REALLY are running their specified low
power. Then - I know of some that really have
mistakenly run the day pattern and power at night -
very very rarely.
Then there are some that just leave their daytime
power and pattern on all of the time.
I hear a station a few states away every night on
one of the regional channels. It is supposed to
run 22,000 watts day/directional and about 50 watts
at night. Their signal totally dominates the channel.
They must be running their day authorization at night,
hoping the wrong people won't notice. (Or the right
people, depending on your point of view.) i don't
think it's right - but their it is.
Speaking of WHA in Madison, WI - years ago one of
my FM DX friends heard the WHA FM transmitter here
in Connecticut via E-skip. Man, it was BOMBING in.
I remember that night well. Every channel on the
FM BCB had about 3 stations. Because of the FM
capture effect, and the rapidly changing characteristics
of E-skip, stations kept changing rapidly on each
frequency. It was impossible to get an ID on anything.
But WHA held it's own for a while, until the E cloud(s)
moved away and other stations came in instead. A local
station (well - about 20 miles away) was completely
obliterated by a station from YOUR STATE, Carl!
I really love scanning the AM and FM bands. Sometimes
you just don't know what you will pick up.
Best Wishes,
Bruce, DOGGRADIO STUDIO 2
Of the very few things I remember clearly, I distinctly recall reading that 20-Watts and above are required on the AM band to achieve skywave type skip. I would guess that the clear voice from WHA last night was 51-Watts, but I am only guessing. The signal drifted into the background and slowly came back for a few minutes, until I stopped listening.
Public broadcasting in Wisconsin is possibly one of the most mature state-wide public radio networks in America. I remember hearing educational programs from the State network in grade school in the 1940s.
KDX also skips. I remember one day I skipped broadcasting because I was out of town.
The sun is setting on the second day of carrier current broadcasting at 970kHz with 2Watts. The audio quality is exactly as good as the AMT3000 & 5000 from sstran, and it is a remarkable technology.
It seems to me that for the home installation only low Wattage is required. I think the FCC's allowance of powers all the way up to 50Watts takes into account large industrial and institutional size CC where huge power systems require more push.
I am guessing that a variable power transmitter with about the top power of 6 or 7Watts would serve the typical home station, and Doggradio's version is right at 6Watts although not built for variable power, but there have already been discussions about using attenuation.
I receive such a strong signal in the house that I may actually reduce power, although I suppose it will be tempting to see what happens with higher Wattage, maybe just one time.
My problem now is that I don't know which one of these stations to listen to.
Thus far the carrier current experience has been a triumph, but certain worries are creeping in.
I think I mentioned that on one house radio, a Zenith Transoceanic, the mid AM band is somewhat disturbed by the strength of 970kHz on about three religious stations.
Now I have tuned across a kitchen AM radio and found that most of the dial is upside down, smothered, mixed up, not there at all, or very crushed.
The power needs to be lowered. If anyone on this leg of the power service is unable to hear their favorite program on the station of choice it would be a disgrace in the part 15 community.
Dreams are no more than bubbles in a haystack finding needles.
The adventure is only beginning.
With all the transmitters going that you have radiating inside your house, and now a CC system added to that, is it any wonder why your radios are all freaking out??
Remember a couple weeks ago when I said there will be something you will discover with all that going at the same time in such close proximity to the house wiring and the transmitters and antennas themselves, and that I would let you discover what that would be?
Keep on going...much much more to discover! 😉
RFB
I started composing this message when
RFB wrote his, just above. It took
me longer - so I just saw his reply
to you, Carl.
What follows, is my take on this before
I saw RFB's reply.
Carl - yes - the radios in your house
are completely overloaded. So overloaded
that some of them do not function
correctly.
Those radios are almost directly connected
to your transmitter. Isn't that right?
When I put a small AM radio right next to
the DOGGRADIO 1690 transmitting antenna,
that radio stopped playing altogether!
It went silent! There was so much RF
field there, that RF energy was induced into
various parts of the operating stages in
the radio. Amplifiers that required certain
bias voltages would cease to function because
the bias voltages would be incorrect.
Especially in the early RF stages probably.
RFB could probably word this better.
On the other hand, a radio plugged into
the wall socket of a house nearby is in a different
situation, in my opinion.
The RF field induced into the power line will
go through many changed before it even gets
next door. A quarter wave length at 970 kHz
is a couple of hundred feet, right? Before
the energy gets out of your house, even before
it gets into the next property, there will be
peaks, nulls, impedance lumps, phasing situations,
(in phase, out of phase) induction with other
objects - all kinds of things that will effect
your transmitter RF energy. A few hundred feet
of AC line after your transmitter RF out may
result in a very very different situation.
The signal could be much weaker.
Again, RFB can either agree with this idea or
disagree. I really don't know for sure, but
it seems to make sense.
I just don't want you to feel as if you are
causing some kind of harm. It is my bet
that you are not.
Also, if you turn off 1550, 1680, and 13.560,
your radios might function better - maybe?
However, RFB IS the expert. Let's see what
he has to say about it.
Best Wishes,
Bruce, DOGGRADIO STUDIO 2
Thank you good people for the points of view, and I will try running ONLY the 970 CC without all the other radiational stations, and we will see the difference.
Another thing I don't like is that tonight at midnight, when the programming ended, I had to climb into the dark basement to turn off 970. There is no way I'd want to leave a silent carrier on all night. There will need to be a remote control system added.
They say there is no rest for the wicked, but I am kept so busy there is never time to be wicked.
A round of applause for Bruce and his analysis of two very important points. The localized RF induction field within the home and the difference through the line variables when the signal arrives next door or down the street.
The thing to always remember is that AC power wiring, be it in a building or strung across the landscape makes for a very VERY lousy transmitting antenna vs the conventional method of sending out a signal over a distance from a central point radiator cut and tuned to resonate at the transmitting frequency.
The vertical 1/4 wave tower/antenna radiating a signal has only a few things to fight against to throw the signal, whereas AC electrical wiring, designed to carry voltage and current supply and not RF, has a ton of things to offer a CC system to fight against to get the signal to the receiver, most of which starts right at the source point, or coupling point. Such a roadblock was immediately found when Carl connected the coupler to the two main hots and the return path was the neutral. A high VSWR resulted and could not be tuned out even though the coupled signal did manage to find it's way along the grid 2.5 + blocks (vehicle radio reception). Even with the high VSWR, his CC signal easily could have been received by radios plugged into AC power past the point where the vehicle radio lost the signal.
The very nature of the electrical wiring and power grid system is what creates all these neat little things Carl has and is still discovering. A far cry from a simple wire or 3 meter stick out back...isn't it! :p
There are indeed similarities between a conventional radiating system and a CC radiating system. Both methods do put RF into the environment. Both methods create a very strong localized induction field, and both create a far field.
The conventional MW vertical allows for the far field radiation to easily propagate away from the center point whereas electrical wiring and the many inductive things around the wiring such as conduits and vent ducts etc, quickly absorbs the potential for significant far field radiation pattern to be produced.
Yes...you can and probably are overloading your radio receivers if they are sitting right next to that coupler or breaker box..including that FM tuner serving as the CC system's STL receiver link. Yes, your other radios throughout the house will get a very strong signal and those closer to the coupling point an even stronger signal.
Each one of those radios will react differently based on their front end sensitivity characteristics as well as detector and IF circuit characteristics and the distance from the coupling point. Sounds to me like Carl's radios are simply doing what would be expected from typical radios within a location of a CC system. Now throw in all those other transmitters sending near field RF onto the same wiring the CC system is, all getting together and having an RF party with intermixing song and dance dinner, some of which will be amplified due to the stronger CC signal present, all within such close proximity to one another, is it any mystery that the radio receivers are going crazy?!
Remember the testing of the exciter on the bench while at the same time a 13.560 transmitter was also in operation with it's transmitting antenna directly ABOVE that same work bench putting a very strong inductive RF field (near field) right onto that LPB exciter..and audio was heard on what was supposed to be a non modulated carrier.
Expand on that experience with this new experience of the radios reacting like they are. It's the same cause and effect, localized within the walls of the dwelling. The chance of this happening next door or down the street is highly unlikely due to the nature of the loading characteristic of the power grid the CC signal is riding on. By the time it loops to the next house, and the next and so on, the inductive field (near field) strength is far less, and radios within that weaker inductive field will not be overloaded and going nuts like those within the very strong inductive field.
The next round of testing and investigating should be done with just the CC system running and the other transmitters shut off. This won't prevent your nearby radio receivers from being saturated, but you will remove any potential intermixing going on between all those generated RF fields in close proximity like they are.
RFB
This morning we started by running only the 970 CC transmitter with an audio tone.
The kitchen radio, a Panasonic table model from the 1970s, was able to scan the entire AM band with no stations in any way blocked by spurious signals from the CC. However, the tone was present at all times in the background as if the radio's amplifier was detecting the station, not the receiver section. In fact I was able to pull in many out-of-town stations without interference. This radio is on a direct AC circuit that goes straight to the power panel.
I turned on 1550kHz, AMT3000, located at the far end of the building feeding a Wintenna (the window frame is part of the 3-meter antenna). It did not cause any disturbance in combination with 970 CC.
Turned on 1680kHz, AMT5000, feeding the Wintenna about 7-feet from the Panasonic radio. Now the radio started being a little blitzy, to use a technical term.
But the most dial bloat happened when SW 13.560mHz was turned on, the indoor dipole arriving at its southern tip only 3-feet above the Panasonic radio. The Panasonic started flapping its tongue and rolling its eyes.
RFB and MICRO1700 have been perfectly correct in their estimate of what is happening here at the Internet Building.
"The kitchen radio, a Panasonic table model from the 1970s, was able to scan the entire AM band with no stations in any way blocked by spurious signals from the CC. However, the tone was present at all times in the background as if the radio's amplifier was detecting the station, not the receiver section."
Sounds like this particular radio is in need of a front end alignment. 1970 eh...ya I bet those IF coils in there and their little caps across their coils have broadened their view of the world in all these years (component aging and drifting from tolerance).
The reason why you heard faint tone across the dial as well as at the 970 point on the dial is because that radio's IF and detector inductors have drifted from their factory adjustment points, which will make the radio see more than just what frequency you tune into. Add to that the proximity of that radio to the coupling point.
"I turned on 1550kHz, AMT3000, located at the far end of the building feeding a Wintenna (the window frame is part of the 3-meter antenna). It did not cause any disturbance in combination with 970 CC.
Again here is an example of the proximity factor. Further away from the receiving radio and adding the unusual radiator (window frame) producing an unusual field pattern from the shape of the radiator. Nothing unusual in that. But to really put it to the test, put that radio a couple of feet away from the Wintenna and I guarantee it will see a tone across the entire dial plus the tuned signal.
See the puzzle coming together yet?
"Turned on 1680kHz, AMT5000, feeding the Wintenna about 7-feet from the Panasonic radio. Now the radio started being a little blitzy, to use a technical term."
I am going to assume that your not feeding a single Wintenna with two transmitters are you? I hope not.
Here we have a perfect example of near field inductive effects. 7 feet separate the radiator from the receiver.
"But the most dial bloat happened when SW 13.560mHz was turned on, the indoor dipole arriving at its southern tip only 3-feet above the Panasonic radio. The Panasonic started flapping its tongue and rolling its eyes."
Isn't that interesting. That 13.560 seems to do the most damage out of the rest. Understandable as it is putting out a bit more signal than the two MW 100mW units and on a much higher frequency. I do hope that thing has a good low pass filter on it. If it doesn't, I suggest you keep it turned off until it gets one, or better yet, shut off until you get it a proper antenna OUTSIDE...on all of them would be the better and proper way to solve your intermixing over saturating issues going on.
Basically Carl..nothing unusual or damaging is going on at all. You are merely experiencing what takes place with that many RF emitting devices in close proximity to one another as well as their proximity to receivers and the unusual radiators being used. Yep..chasing your own tail here my friend.
Looks like a whole revamp and rebuild of your station's transmitter arrangements will be required, starting off by putting that 13.560 onto a proper antenna outside. Same with the two SSTran MW units. They too are getting inductive near field RF from that 13.560 TX just like everything else is.
It's a good thing these TX's are low power. But to a radio receiver with front end amplifiers and tuned circuits, it is no mystery at all why the radio receiver is acting like it is with all these intermixing RF fields bouncing around and in between the walls of your house.
In a nutshell...the problem is localized and within your own home. The fix is known and should be done. I hear the summers there are nice and perfect for doing some outdoor activity....like setting up proper antennas for these 3 transmitters!
Besides all that..isn't the point to get the signal out to listeners BEYOND the confines of the walls of your house??
If all you want to do is broadcast in the house, then put attenuators on those TX's, especially the 13.560 and shorten their antennas so the near field being produced is less destructive. Your lucky so far that all of this, even prior to the CC system, has not over driven all the radios you have and or done some damage to other circuits in other devices.
Remember our two friends...(a) and (b). Now include a (C).
The (C) is the first letter of your first name, and it is the (C)'s arrangement of these things that is the cause which is creating the undesired effects.
Anything else? :p
RFB
Why does "clear clarity" make me think of wine? Oh, I guess because of "Claret" which fits that section of the vocabulary. I forget, is Claret red or white?
Everything RFB has said throughout the CC project has been correct and I have tried and proved each stage of the process, which is why everything has worked as predicted.
Even the kitchen radio is, yes, a drifter. Even being tuned to a solid signal that radio will drift and needs occasional re-tuning. Of course part 15ers love tuning things, so that is no annoyance. Once I picked up a Florida shortwave station at about 1mHz, middle of the AM dial, and I looked it up and it was a 1-million Watt station! But that never happened again.
Since we managed to sink an 8-foot ground rod for this project, we certainly can get some outdoor antennas built. It would be nice to "put the RF out the door," so to speak.
AFTER THOUGHTS: Putting RF out the door sounds like we have a dog named RF. That made me think of the word "leash," then my brain noticed that an antenna is not unlike a leash. How about calling it a "sky leash?"
Another day on the CC with programs going out through the wall and across the poles.
Because 2Watts works so well, I have the sense that more Wattage has no actual use in this setup, might even cause problems if we edged up to 20Watts (the max).
But I would like to try less power, so we are preparing for a 1Watt test.
You will hear all about it.
Hello Carrier Current Journal readers.
Yes, this is the new online news zine, The Carrier Current Journal.
During the first few days of full time carrier current operation, KDX CC ran on 2-Watts of power. But today the power has been cut in half, we are transmitting with 1-Watt.
We are testing the low power efficiency of broadcasting with the neutral injection method, which has been proven very effective in this installation.
More test observations later.
So........when driving around tell us about your range...
Headed east toward the same direction the electric lines from our transformer aim, and we have an interesting difference to note between 2-Watts and today's power of 1-Watt.
With 2-Watts the strong signal on 970kHz could be heard for 2.5 blocks before it dropped very rapidly into no signal.
Now, with 1-Watt, the strong portion of the signal holds for 1.5 blocks, then there is a weaker signal but still receivable, until the 2.5 block point, when the signal disappears.
I did another test using a portable radio, to see how well the signal does in the rear of the building, back where no electric lines are run from our particular transformer.
There is one possible exception to the statement just made, the next house on the east is on the same transformer, and if they happen to have an electric line out to a backyard lamp post, that would make a difference. Due to a high fence I do not know what's over there.
The 970 signal became slightly weaker but was still very usable, up at the mulch pile, about 125-feet back.
I believe we can safely return to a 2-Watt status, until the next test, when we will run 3-Watts.