I have a series resonant loop ......

A series resonant loop. First, this is a contradiction in terms and
as your interpretations hinge upon this reading, it bears examination.


OK, now we're making progress. I knew there had to be an explanation
for your insistence that the antenna presented a 2K impedance to the
feedline! I absolutely knew it could not be correct and you were
equally determined::

Let me describe exactly what I hope to build, and you can enlighten me
regarding what the proper term is. Thanks for hanging in there, the
road was a little bumpy....

I'm thinking feedline attached to one end of the wire. The other end
of the wire is attached to the capacitor bank. The other side of the
capacitor bank is attached to the other feedline terminal. Or, stated
another way, the cap is in series with the wire and the 2 transmission
line terminals are connected to the left over cap and the unused wire
end.


A series tuned circuit is a low impedance circuit, so 60 KHz signals
from the antenna are passed to the receiver

To be in series, you have to describe the source and its common, you
simply describe the loop. With this, you neglect the coupling between
the actual source of power, a remote transmitter, and the antenna's
Radiation Resistance. This value appears no where in your analysis
and yet it is largely responsible for the atrocious efficiency of this
breed of antenna.

OK, but I hadn't thought this entered into the calculations of the
loop.....it is what it is and we all know it's too damn short and too
damn close to the ground to be efficient. At 60 Khz, there is so
little difference between 5 feet off the ground and 50 feet off the
ground, that I guess I never thought it mattered much...and, so tended
to skip over these details. Any antenna that I can build with my
budget will never be efficient:: Is this a fatal error, or do I
really need to look at this issue to proceed?

I understand these types of shortened antenna are often less than .001
percent efficient because they are so short relative to the wavelength
being transmitted or received.


I've thrown together a quick model of your 5M on a side loop using
(and being generous) #1 wire. The bottom of the loop is 10M above
ground. In terms of performance relative to an isotropic antenna it
is down 60dB. It displays an impedance of:
Impedance = 0.05849 + J 10.37 ohms
An addition of a 0.2555µF capacitor draws this down to:
Impedance = 0.05851 + J 0.006073 ohms

Please note that the capacitor is perfect, no ESR whatever. In a
system with Zc = 0.0585, this antenna presents a 1.11 SWR. The half
power points of its resonance are only 600 Hz apart. Hence a Q of
100.


OK, are you telling me my receiver would need to have an (impossibly
low) input impedance of .06 ohms to work well with the antenna I've
planned?

This is without any extraneous detector circuitry whatever. We will
see where its addition leads.

By simply inserting your 2 Ohms (I know full well where my 10 Ohms
will take us) - in series - (again, your thesis) and re-assigning the
system Zc to that same 2 Ohms, this antenna presents a 1.077 SWR.


OK, I'm not completely understanding the last paragraph. Have we
abandoned the .06 + j10 real loop impedance and/or are we talking only
about feeding a 2 ohm impedance loop into a 2 ohm impedance receiver
(which seems to be a match made in heaven at first glance)?

If we aren't considering the .06 j10 anymore, are you trying to
impress upon me that even a perfectly matched 2 ohm antenna connected
to a 2 ohm impedance receiver knocks the Hell out of the Q by that
large of a factor?? If so, I can understand the need for the buffer
follower you suggested earlier!!

Send me a sign, I sense an incoming lightening bolt::

Another user just suggested I think of Q as stored energy and that
anything that consumed that energy severely lowers the Q. I can
understand that since the goal of the impedance matching is to
transfer as much of the stored energy as possible. Further, if this is
the case, it seems an active antenna matching buffer amp (impedance
shifter) is necessary when using a loop of the type I planned. Not
sure whether I am getting it or going off on another tangent....like I
said above, send me a sign::


Sounds hunky-dory, right? Except when you look at the Q which has
plunged to 2.9 and the antenna loss now compares to -75dB compared to
an isotropic.

Your receiver, in series with the loop, has just killed 15dB of gain
and wiped out the Q by 95%. Not bad for a day's work.

I will forgo the remainder of your questions to allow you to digest
the material above.

Yes, please do forgo, for the moment anyway...... Please specify
whether you are explaining a 2 ohm impedance loop hooked to a 2 ohm
impedance front end (in the preceding paragraph). Then, we can proceed
I think..... I'm trying to assume NOTHING. Please forgive me if I seem
to need a lot of clarification.


Not sure what I did to deserve an honored position in your kill file.

This is not the kill file of unsophisticates simply ignoring by
posting name. Agent has much more flexibility to read headers and
judge what is spam.................

OK, understand. When you made the original comment, I thought you were
saying I had done something purposely inappropriate. I use Eudora in
order to avoid the Bill Gates problem, so I understand the difference
between sorting to the trash and sorting to the junk mailbox! Trash is
trash, gets emptied forever when I close the program. Junk is possibly
trash, but doesn't fit all the criteria, so it's saved (just in case
it really isn't garbage).

Got yah.


your
headers appear to be spoofed. Now, tell me that you aren't doing
something out of the ordinary like passing mail through an open relay.


Well, I'm not sure how and what happens after I hit the send button.
To the best of my knowledge, I am not doing anything of that nature.
It's (my email) a paid service, so it should be on the up and up. Is
it possible it might be a DSL issue, where the IP address is masked to
some extent?

Thanks for hangin in there.

T