Hi, I'm Mr. Loudmouth. I yell a lot.
Well, not really. I just put those
comments in the last post in caps so
nobody gets slightly killed - if they
try my CC experiment - but don't
completely understand what is going on.
Ahem.
Seriously, in reference to WSM. There
are some great things about that radio
station. There is a live person there
all night playing music. What other
clear channel AM station does that? I can't
think of any. And it comes in great
here in Connecticut at night.
I decided to listen to it last night as I
was drifting off to sleep.
As a struggling jazz musician (I used to
be pretty good) I can appreciate just about
any kind of music - because music is hard
to make and have it be good. You have to
know what you're doing. So even though
county music isn't what I usually listen
to - there was a lot of really great music
on WSM last night. Really good stuff. Both
new and classic country.
If you look at Radio-Locator.com you will
see how interesting the 650 channel is at
night. In the U.S., Canada, and Mexico
there are 26 stations on 650. A few of
those stations go off completely at night.
A lot of them drop to very low power. And
even some that are very far away from
WSM fire their pattern away from Nashville.
As I was listening to WSM last night, I
turned the radio to a different direction
and DID get another station on 650. I think
it was Spanish language. However, before the
top of the hour, the unknown station faded out,
so I was unable to get any kind of ID.
One of the WSM IDs mentioned that they have
been pretty much been the same for 86 years.
How wonderful is that?
I think I'll listen to them more at night.
Again, Robert, KC8GPD, thanks for the
great photos!
Bruce, DOGGRADIO STUDIO 2
I have some good news and some
bad news, but first I will tell
you about this morning's experiment.
I turned the CC set-up on and went
for a walk around the block that
is opposite my street. I heard
the signal the entire way. Completely
around the block.
Then I unplugged the transmitter A.C.
cord from my homemade coupler and just
plugged it into an outlet strip. Then
I went for the same walk around the same
block across the street.
At first I thought there was no difference.
But then I got out of what must have been
the near field.
The signal was not present around that block
across the street. It wasn't there.
So, I guess this shows that the coupler really
is coupling. In other words, it's working.
That's the good news. Now here's the bad news.
I am getting a 10 kHz hetrodyne from a New York
station all around that block. I had thought
the signal from 1010 New York wouldn't be that
strong. Maybe this is just a good day for
daytime ground wave and skywave? Maybe the
D layer is not that oppressive today?
But - and this is the bad news - I don't think
I can use 1020. I'm not sure anyway.
So I came back to the transmitter. It is
running without the coupler going anywhere.
It is just running into the attenuation
network and the LC, and the LC secondary.
And of course, the LC secondary is not
connected to anything.
There is no RF field coming off of the
LC coupler now. The resistors on the
attenuation network are pretty hot.
The SWR in still unity. So i guess the
resistors are now taking all of the
power, and maybe some of the field is
coupling to my outside antennas, or
other wiring, I guess.
I guess I's better turn it off before
those resistors get too hot.
So, the experiment worked pretty well.
But, I guess I'm still on the wrong
channel.
Best Wishes,
Bruce, DRS2
At first I didn't post about Doggstudio 2's technical findings, for the very reason that all I was doing is thinking about it. I wasn't sure about what I could say, and it makes very little sense to come on here with nothing but silent thoughts. But there was a clicking noise and all at once I know what to say...
Bruce, your experience with the NY station at 1010, exactly next door to you at 1020, is a perfect match to my reason for NOT going on 660, which would have been great, EXCEPT that it was right next door to 650, WSM, which we have mentioned.
In your case you happen to have a 1020 crystal, which is why you ended up on 1020. In my case I never had a 660 crystal, so I was able to make a choice. In your case, (if I recall correctly), you were given a crystal that already was 1020, and you did not have a choice.
Probably the toughest part of carrier current is getting the right crystal and then tuning the transmitter for the right part of the band.
Building a PLL frequency selector would solve half of that problem, as RFB has so well discussed.
But of course, once you get established at "the right frequency," you may never need to change it again.
Having kids is much simpler.
Well, it's always nice to hear from you!
Yes, we are sharing the experience of not
being on the right channel.
For me, 1020 is great if the signal is
just in the house. So I will go back
to my leaky coax set-up in the house.
And I will look for another way to
get onto another channel.
What channel and how will I get there?
It doesn't matter. The coupler experiment
worked and that makes me happy.
Always good to hear from you.
Bruce, DRS2
P.S. Yup, I think having kids IS
simpler.
There is one other thing. The PLL
exciter going into the crystal socket
is great, and I might do that. BUT
in this particular transmitter, I
believe modifications will have to
be made to the crystal osc. circuit for it
to be driven by the PLL.
We'll have to wait and see if RFB
has any take on this. I'm sure he will.
As I noted before, an LC equivalent circuit with a varactor diode (preferable double-ended) to replace the crystal element, then controlled by the PLL.
Not going to be easy without a roadmap to the unit, but not impossible.
RFB
Yup! Well, my friend, we will just
see how it goes.
Best Wishes,
Bruce, DRS2
First thing is to create an LC circuit which will run the tube's oscillator section. Once that is done, add a varactor to the tank (double back to back varactor for finer tuning).
Google crystal equivalent circuit for many examples.
RFB
I'm already looking.
This is very very interesting. But whatever
I do, it will take a while.
Best Wishes,
Bruce, DOGGRADIO STUDIO 2
So here I am thinking again and reflecting back on the fact that the auto radio stops hearing AM 670 CC at about 2.5 blocks. I am guessing that the power line off of my transformer or perhaps the neutral line from my electric service ends at that spot, running into the ground for the last time.
But what about next door to that?
What about a few more homes beyond that point?
Is anything getting into their power wires that might be me and my signal?
"What about a few more homes beyond that point?"
The next step is to take a decent portable to the next power pole beyond the 2.5 block drop point, walk up to it with the portable and see if the radio starts picking up the signal within 1 to 3 feet. If it does, your signal is getting further down the line past the 2.5 block point and into the other homes.
RFB
"This is very very interesting. But whatever
I do, it will take a while."
Hi Bruce!!
Well there isn't any deadline that I am aware of! 😉
The roadblock here is that the RC-6A uses the same tube for both the oscillator and modulator/final. And adding even more difficulty is the unit has no power output adjustment so experimenting with the front end of that tube (oscillator) while it's also performing amplification will make things a bit more difficult. When it's time to test the LC circuit for in-band oscillation, use the regular dummy load on the output and not the new resistor load/attenuator stack.
Well I wouldn't call it a roadblock..but perhaps a speed bump so we will have to slow down anyway and take our time! 😀
Besides..there is a speed trap past the first block! 😉
RFB
There is a lot of information contained in this thread, almost too much to wade through and absorb.
RFB, would you consider writing and posting a Carrier Current Primer with basic information all in one place for those who are considering CC? Perhaps a generic presentation on the fundamentals?
Neil
Hi Neil! And while we're waiting for RFB to
answer Neil's question - I have some more
CC test data to post.
Maybe 1020 isn't such a bad channel at all.
I'm beginning to think the interference I
heard yesterday was from something else. 1020 might
be OK. I thought it was a het yesterday from
a station down one channel, that I
heard. However, it didn't seem to be there today. (???)
I'll have to check again later.
In any case, I'll just post the findings of my
experiment.
I turned the transmitter on this morning,
and tuned for
lowest SWR again. I was on my way to work,
so I set a timer so the CC transmitter would
go off in 15 minutes.
After we finally actually got into the car, we
drove around some adjacent blocks, that come
up against the other side of my street.
I was surprised to get reception on the car radio
3 blocks down and 3 blocks over. So we drove
around all nine blocks in the three by three area.
The signal was there around all of the nine
blocks! This really surprised me! So the signal
was not very strong - but it was in ALL of those
areas. We started to go out of that perimeter to
investigate if there was further coverage. But at
that point my digital timer at home turned the
transmitter off. (All of the blocks travelled had
power lines all around them.)
So it looks as if there is a nine block coverage
area at least.
I am finding it very very interesting that the junk
box coupler I built is doing this. I find it hard
to believe, but it seems to be true.
As many of you have read - RFB is advising me how
to rig an external PLL to run the transmitter on
a wide range of frequencies, and I will be looking
into that.
However, 1020 may not be so bad after all. I'll have
to do a bunch of tests over a period of time.
I also know somebody who has a 970 kHz crystal
that I might be able to get. 970 is empty here
during the day. It might be something else to
try if I can get my hands on that 970 rock.
I also have some oddball crystals on the AM band
that are not on good channels. But it might be fun
to grind them in order to raise their operating
frequencies to something I might be able to use.
Crystal grinding
is not a lost art. There are still people doing it.
My eyes are limited, but I don't think it takes too
much sight to grind a crystal, and besides, I
have nothing to loose anyway.
Well, that's my report. Again, this is really really fun.
To me, it's like a whole new world to investigate.
Best Wishes,
Bruce, DOGGRADIO STUDIO 2
Hi Guys:
My previous post talked about the
coverage coming from the power lines
around a 9 block area. Well, I'll have
to check the map again, but now we
are looking more at like 12 or 15 blocks!
(This would be in a 3 block by 5 block
area.)
This is NORTH of my street. Here's the
interesting part. Unless my map reading
is wrong, there seems to be very little
coverage on the SOUTH side of my street.
This must be the way the GRID goes! (Or
doesn't go!)
Yikes! This is SO INTERESTING from an experimental
standpoint!
My mind is still having trouble comprehending the
fact that, the signal will be stronger(?) inside these
houses, where radios are plugged into the AC outlets.
If the radio has a transformer - will that stop the
signal, or will the signal just sort of leak past the
transformer?
And what about battery powered radios that are placed near the
AC outlets? How will they perform?
And the strength of the signal - it is weak along the
whole route, and roughly the same strength, until you get
over to the north side of the 3 by 5 block perimeter.
Then the signal is a little weaker.
Here's what I don't understand. The transmitter is not
near the power panel yet. The LC set-up doesn't seem
to be putting out much field strength, certainly not
after the near field. The set-up is on the TEST BENCH on
the first floor - not in the cellar. And the transmitter
ground is connected to the radiator. Are the pipes
radiating, too? If that is so, then I must get this
thing downstairs right away. And I am really not in the
position to put a ground rod in. (The explanation
for that is a long story.) The plan is to have the transmitter
float above ground (from the house wiring) and ground
it to a water pipe in the cellar. The plan also is to have
the transmitter fed by an FM tuner (like Carl is doing.)
The FM tuner will be tuned to the DOGGRADIO FM
Part 15.239 channel. The FM tuner will also float
above the house wiring ground..And the resistor attenuator
network and the coupler LC will be shielded.
I'm concluding these short tests for now. The hardware
will have to be moved. I DO NOT want to do anything
wrong.
It still surprises me that this Carrier Current thing seems to be working.
It's just like nothing I've ever seen before. New territory.
And I don't want to run it until I really understand what's
going on.
Best Wishes,
bruce, DOGGRADIO STUDIO 2
Doggradio2 seems to have the "Midas Touch," his CC experiment turned to gold right away.
Based on how well it's working I think you can leave the equipment where it is, unless you need to move it for other reasons.
Refinements lie ahead including building the Standing Wave (SW) detector.
The questions you asked can be answered somewhat by what I am finding with my CC setup... power transformers in the radio don't matter.... the RF energy is there and it jumps to radio reception both to AC plug-in sets and portables.
If there is a friend in the outlying coverage area perhaps they will allow you to stop by for an indoor reception test.
Once you declare the experiment concluded and have a definite system, I hope you might draw the diagram of how it works for posting here on the site.
The exceptional thing is that your method avoids ever handling high power wiring. The safer the more pleasing it can be to users in the future.
If I were you I would tell all your easter friends that you are an acclaimed inventor of a new radio coupling method. When they start asking what that means, do your thing of saying you'll get back later.
Perfect!