Somewhere on the net, is a 2 watt vacuum tube CC
schematic that looks similar to the 5 watt circuit
mentioned above.
I think a lot of people on this board have seen
that 2 watt circuit, also.
The guy who published the Popular Electronics
5 watt transmitter made no mention of neutral
injection. I wonder why or why not?
Actually - I had never heard of neutral injection
either - UNTIL I came here to PART15.US.
Thanks again,
Bruce, DOGGRADIO STUDIO 2
Because my CC coupler is homemade, I conduct
experiments late at night after midnight
usually.
This check involves NO DIRECT CONNECTION
to the AC line. (Just like my coupler.)
All I did was plug an extension cord
into the wall socket. Then I got
a CB/HAM field strength meter - you
know - the kind that costs 20 or 30 dollars.
I just wrapped the extension cord around
the antenna of the field strength meter
that I was holding in my hand. The other
end of the extension cord was not connected
to anything.
I received a very very small meter reading. It
was just a little bit more than zero, but
it was something. I think this field strength
meter probably uses a diode like a 1N34.
Knowing that a 1N34 takes about 0.2 or 0.3
volts to turn on and drive the meter tells
me that there is some RF voltage on my
house AC line, just like there is supposed
to be. (And there was no direct connection.)
To be sure this was really coming from my
transmitter, I put a timer on the transmitter
to turn it off a minute of so.
And I just stood there - holding the meter,
with the AC cord wrapped around the antenna.
I had a radio on, and was listening to
the signal. I watched the slight deflection
on the meter. And I watched and I watched.
A minute or two passed, and I heard the timer
turn off the transmitter - and the signal
disappeared from the radio. At the same time,
the needle on the FS meter fell down to zero!
This was in the next room about 30 feet away
from the transmitter.
Then I went to the other end of the house and
tried it. The results were very similar. I
received a very very small reading on the FS
meter. When the timer turned the transmitter
off, the small reading dropped to zero.
So I guess that shows that the coupler is
putting some RF energy into the AC line.
For whatever it's worth.
Best Wishes,
Bruce, DOGGRADIO STUDIO 2
Still operating daily at a temporary frequency of 670kHz with 2-Watts neutral injection. I have made note that neutral injection in this case is very stable. Every morning and evening I check the SWR and it never varies from 1.5:1.
Have prepared to order parts to re-build the output filter for the permanent frequency of 970kHz.
Am also wondering about having a backup transmitter, and the idea of the moment is to rebuild the Ramsey AM25 according to Radio8Z's instructions, with a linear amplifier to reach 2-Watts at 50-ohms.
That plan makes maximum use of on-hand resources, as there is no other application for the Ramsey at this time.
ABOUT Doggradio2's EXPERIMENT WITH A METER.
It does appear that you saw enough of the AM CC signal on your meter to indicate its presence on the AC line. Evidently the 60Hz AC energy is below the range of you meter.
With that small reading you can try to find coupling combinations that boost the RF reading on that meter.
Thanks for your feedback.
I'm glad your CC system is stable.
That's a great idea about using the
AM-25 as a backup.
Is that AMP for the AM-25 2 watts input
or two watts output?
Best Wishes,
Bruce, DOGGRADIO STUDIO 2
I sent you an email containing both an image and schematic of a 10 watt solid state MW CC amplifier shortly after you won the auction on ebay for your TCU-30 coupler. If you can find that and print out the image and schematic, your all set to build a very stable and clean linear for that AM-25, and there you go, a complete backup system.
RFB
"So I guess that shows that the coupler is
putting some RF energy into the AC line."
Depending on what is on the line, the meter may also indicate the EM field produced on electrical wiring when current flows through them. Heavy loads create even stronger magnetic fields along the length of the wires which could end up being added to the signal your trying to measure.
Also consider the other induced noises on the lines by inductive loads. This stuff may also give false readings.
Your going in the right direction Bruce. Just keep in mind that the AC lines do have a bunch of garbage on them and could be picked up by the meter.
RFB
Yes, RFB, the linear amp I had in mind is exactly from the diagram you sent. We are talking serious backup so that 970 will never go dark.
Well, RFB - thanks for the info on
detecting RF on the AC line.
This testing at night - - I feel like
a 250 watt daytimer testing during
the 12:AM to 6:AM test period. (Or
whatever the time is.)
It's REALLY BEWILDERING, but
really really fun, too!
Best Wishes,
Bruce, DOGGRADIO STUDIO 2
So it's about 12:30 AM here in good
old Connecticut. (About 45 minutes ago.)
I fired up the experimental CC
transmitter/coupler set-up to look at
the near field. 1020 kHz.
I ventured out of the house and down
the street.
The near field disappeared and I kept
walking. (The near field seems to be
in compliance with FCC regs. by the way.)
Then:
KDKA/1020 in Pennsylvania was not very strong.
I had heard a bit of what sounded like auroral
conditions earlier in the night.
Did we have a spike of solar activity recently?
What is this hash noise? WTIC has IBOC,
but they are on 1080. This is a selective
radio, so what's going on?
Oh yeah, that's right, it's WBZ in Boston.
Well, I really like WBZ, so they can do
whatever they want as far as I am concerned.
They are on 1030. If they have IBOC noise
on 1020, well that's OK with me. I can just
null it out. (Although, I know of a station
in New York on 1040 that is very very unhappy
about the IBOC hash from WBZ, and I think
that they should be unhappy. If I owned a
REAL RADIO STATION, and it was getting pounded
by IBOC hash at night, I'd be pretty miffed.
Alright, that's enough of that.
BUT THEN - WHAT IS THIS?
"R R" in Morse code, coming RIGHT OVER
everything on the channel. Yikes!
Radio Reloj is HERE, TOO?? ON 1020???
GOOD GRIEF!
All though a lot of us have heard them
on 570 kHz, RADIO RELOJ is all over the place.
I have heard them on 790, 860, and 1010,
as well. SO NOW, there they are on 1020!
That's five frequencies for me, as near
as I can recall. I actually think I have
heard them in some other spots on the AM
dial, but my records are incomplete.
So I LOOKED THEM UP. Radio Reloj has
22, yes count them, 22 transmitters in the
AM band, and 16, count them - 16 transmitters
in the FM band. A prominent FM DXer in
Massachusetts heard them on 107.5 during
his morning commute, a couple of years ago,
via E-skip. (I wish I was there for THAT ONE.)
Anywayyyyyy...
I walked back to the house, turned the
experimental set-up off, and did some
chores.
Now I can't sleep. But that's OK.
That's why I'm typing this.
It's much later now, because I don't
type very fast.
Maybe I'll do a little more AM BCB
listening, and call it a day.
Best Wishes,
Bruce, DRS2
Doggradio 2 said he was out late after midnight and heard "hash noise."
Last night well after midnight I heard loud static popping coming from a radio on the other side of the wall left turned on after 670kHz (my CC station) had turned off. I had been asleep, but I wondered if a thunderstorm was coming, but there were no storms reported in the area. The popping was constant, like popcorn, and it was across the whole dial and on long wave, but not much on shortwave.
I heard somewhere that radio static has been known to occur when an earthquake was eminent, but we did not have an earthquake and this morning the static is quiet.
When unable to sleep I have a solution that worked everytime with my wife, when she couldn't sleep. I said, "I will tell you my life story." And I started, "It all began on 11th Street in a small town in Wisconsin." By then she would be sound asleep.
I LOVE IT!
I'll be back with more comments in the
fairly near future.
Bruce, DRS2
A week or so ago, it could've been Old Sol acting up, but not today:
http://www.swpc.noaa.gov/today.html
If I understand correctly, the solar chart linked by Free Harbor Tiny Radio was from a week ago, but when I linked to it just now it is updated to today's date and shows a lot of solar racket. I am guessing that the odd noise last night was indeed a message from the sun!
Depending on how large the CME is, and what direction it flings, is what determines the time frame of it hitting the Earth and its duration.
A CME can occur days before we see the effects. If massive enough, that CME can cause disruptions for hours and even days at a time. All forms of communication and electrical systems will be affected.
Best way to monitor is to log on to the SOHO site and watch the daily SOHO images and videos of the Sun. Right now there is one that shows a very huge CME discharge. They call it the Pick of the Week. Note the massive CME shooting to the Sun's North West. That is ONE HUGE CME, which occured on April 20. There have been much larger CME's recorded by SOHO before which would make this one look like a baby shower.
Welcome to the real world/universe/cosmos reality show! Where the Sun never lies or holds anything back!
RFB
When the sun shoots out a flare, we
see evidence of that in the form of
light traveling at the speed of light.
(Makes sense,)
There is that roughly 8 minute lag
from when the event takes place to
when we detect it with our eyes.
I just can't remember what kind of
particles hit the earth later, and
what the time lag is for those
particles.
More testing of the great 1020 is
to follow tonight. A small test
will occur in about an hour, where
the coupling between the LC primary
and the secondary will be adjusted.
I have to get some better data on this.
Best Wishes,
Bruce, DRS2