OK Richard,

I like to think I'm not stupid, but reading your last message.......

That being said....

I just went through and reread every single word in this entire thread
including all the replies and I have the following questions:

-------------------------------------

I have a series resonant loop with moderately large conductor wire and
reasonably high Q capacitors. It's tuned to resonate at 60 KHz.

A series tuned circuit is a low impedance circuit, so 60 KHz signals
from the antenna are passed to the receiver and other frequency
signals are attenuated as the X(C) or X(L) on either side of the
resonance frequency attenuates them. Using Reg's rjeloop3 we get 25.4
uH for the loop inductance, and it resonates at 60 KHz with 286,700
pF. It also gives us the X(L), which is 9 ohms and (presumably) the
X(C) is -9 ohms. It estimates Q at 221. The 2 reactances are equal and
opposite, they cancel each other out. This leaving us with the
effective R(ac) for the loop inductance and the effective R(ac) of the
resonating C. The sum of these 2 resistances gives us the net
impedance of the loop. I know that the ESR of the cap is in the
milliohm range and the same for the wire, but I don't know the actual
impedance of loop. For a parallel tuned loop, Reg's program gives me a
value of 2K ohms. I don't really know what the value is for a series
tuned loop such as I will have.

Why does this make my antenna look like 2 K ohms impedance? I was
(admittedly guessing) that it looked more like 2 ohms. Maybe 2 ohms
isn't right, but can the impedance of a series tuned loop made out of
number 2 copper and low ESR caps be 2 K ohms??

-------------------------------------

My receiver measures around 2.5 ohms input impedance, verified by 2
different test methods...maybe that's not absolutely accurate. But,
you said it should have looked like 10 ohms instead. I accepted your
number however, let's say it's a 10 ohm impedance input from now on.

I believe that the antenna and receiver should be designed for maximum
power transfer which means making the antenna and the receiver front
end equal with regard to impedance. Is this correct? Is maximum power
transfer indeed my goal?

-------------------------------------

Regarding the integrating caps C value:

Yes, I understand I've lowered the effective series resistance (by
modifying the input circuit) that charges and discharges the
integrating caps. And, yes, I know different values of caps will be
needed. And, NO, I haven't addressed that issue yet. But, thank you
for pointing it out to me. I had thought these caps should be greater
than 1 uF and possibly larger. At this time, it's not a priority as
Winter is coming here and I have to get the antenna installed and
tuned. Fine tuning the receiver will come in the Winter when VHF
quiets down and the snow is 10 feet deep in the woods. For now, the
priority is making sure the antenna is all set before the snow flies.
Thank you again for reminding me that the integrating caps need to be
a different value. Since I might have to have a different input
circuit, or even an tuned circuit in the front end, I don't want to
address this issue now.

-------------------------------------

So, how do I fix it??

I'd be perfectly happy redoing the input circuit for 50 ohms input
impedance and putting some selectivity back into the front end if
that's what it takes to have the receiver function. My idea of
matching a 2 ohm impedance antenna to a 2 ohm impedance receiver
without any tuning at all (other than the loop antenna) was just that,
an 'idea'. If it doesn't work, then it doesn't work. But, on the
surface, it seems reasonable. It appears the major problem here is
that you think my antenna impedance is 2K and I think it's 2 ohms (or
less). So further discussion is a waste of time and bandwidth (until
this issue is resolved).

-------------------------------------

My primary question is about the impedance of a loop antenna made out
of 20 meters of #2 copper in series with each other using low esr caps
and tuned to resonance at 60 KHz.

-------------------------------------

schematic I sent you by email.

Didn't get it. My Kill filters barely let your last schematic
through.


Not sure what I did to deserve an honored position in your kill file.
I confess to being stubborn and cranky, but I don't think I was
disrespectful or made inappropriate comments. I won't email you
anymore schematics.

Obviously, if I had all the answers, I wouldn't need to ask here. If
you could shed some light on the series tuned antenna impedance and Q,
it would help me to make forward progress and I'd appreciate it. Where
have I gone wrong?

TNX,

T