On Sat, 17 Nov 2007 10:30:06 -1000, Tony Giacometti
wrote:

Richard, I use a vertical antenna, for transmitting its great, does a fine
job, but for receive, with the noise in the neighborhood, its not the best
option. I have tried to use an ANC-4 noise reducer but the noise isn't
reduced enough to hear the weaker signals.

Hi Tony,

Leaving that aside for others to comment....

So, what to do, I followed the instructions for building the loop from W2YR
and KN4LF and from this link
http://www.hard-core-dx.com/nordicdx.../coaxloop.html

There is a world of opportunity in making a mistake with this monster.
It goes a long way to do something difficult that could be done vastly
easier.

As I wrote previous I have 2 good preamps but the signals are still very
weak.

You state that there is no gap. The page you supply clearly shows
gaps at the top of the two loops. Anything you hear is a function of
the poor shielding. By your description of your construction, you
shouldn't be able to hear anything at all!

Have you ever built one of these?

No, not one of these (there are too many frogs to kiss them all).

I don't have room for a beverage but if I am unable to solve this loop issue
I will probably have to consider a K9AY array which will force me to move
other antennas around on my 1/3rd of an acre.

A solution is vastly simpler than that - and you can still build a
loop. Google for more designs and submit them here for review (the
one you provided rates low on the sanity scale).

73's
Richard Clark, KB7QHC

Richard Clark wrote:

On Sat, 17 Nov 2007 10:30:06 -1000, Tony Giacometti
wrote:

Richard, I use a vertical antenna, for transmitting its great, does a fine
job, but for receive, with the noise in the neighborhood, its not the best
option. I have tried to use an ANC-4 noise reducer but the noise isn't
reduced enough to hear the weaker signals.

Hi Tony,

Leaving that aside for others to comment....

So, what to do, I followed the instructions for building the loop from
W2YR and KN4LF and from this link
http://www.hard-core-dx.com/nordicdx.../coaxloop.html

There is a world of opportunity in making a mistake with this monster.
It goes a long way to do something difficult that could be done vastly
easier.

As I wrote previous I have 2 good preamps but the signals are still very
weak.

You state that there is no gap.

sorry, but maybe I wasn't clear enough, there IS a gap - just like the one
in the link.


The page you supply clearly shows
gaps at the top of the two loops. Anything you hear is a function of
the poor shielding. By your description of your construction, you
shouldn't be able to hear anything at all!

Have you ever built one of these?

No, not one of these (there are too many frogs to kiss them all).

I don't have room for a beverage but if I am unable to solve this loop
issue I will probably have to consider a K9AY array which will force me to
move other antennas around on my 1/3rd of an acre.

A solution is vastly simpler than that - and you can still build a
loop. Google for more designs and submit them here for review (the
one you provided rates low on the sanity scale).

I did do a search for loops of this type and basically they are all the
same.

I have been told Wellbrook makes good loops, but I don't like the idea of
spending $300-$500 for one at this point.


73's
Richard Clark, KB7QHC

On Sat, 17 Nov 2007 12:02:35 -1000, Tony Giacometti
wrote:

I did do a search for loops of this type and basically they are all the
same.

Hi Tony,

If the link you supplied is an indication of sameness, they are
equally complex and problem magnets.

No, loops are not all the same. There is quite a variety (you
supplied one poor variant to a simple turn of wire in the sky).

I have been told Wellbrook makes good loops, but I don't like the idea of
spending $300-$500 for one at this point.

More than $20 spent is only buying custom designed furniture.

73's
Richard Clark, KB7QHC

Richard Clark wrote:

On Sat, 17 Nov 2007 12:02:35 -1000, Tony Giacometti
wrote:

I did do a search for loops of this type and basically they are all the
same.

Hi Tony,

If the link you supplied is an indication of sameness, they are
equally complex and problem magnets.

No, loops are not all the same. There is quite a variety (you
supplied one poor variant to a simple turn of wire in the sky).

I have been told Wellbrook makes good loops, but I don't like the idea of
spending $300-$500 for one at this point.

More than $20 spent is only buying custom designed furniture.

73's
Richard Clark, KB7QHC


OK, other than leveling all existing structures within 2,500 ft of my house
and burying the power lines, how do I solve this problem?

also, if these loops don't work then why do these designs exist?

Tony Giacometti wrote in
news:suednRqSYJd58aLanZ2dnUVZ_uDinZ2d@hawaiiantel. net:

also, if these loops don't work then why do these designs exist?

Tony,

A few questions:

1. With a 50 load on the preamp input, when tuned to a quiet spot in the
band, RF gain full, preamps on, telephony bandwidth, does the S meter
deflect at all?

2. If no s meter deflection, note the receiver audio output voltage.

3. With the loop connected on the preamp input, when tuned to a quiet
spot in the band, RF gain full, preamps on, telephony bandwidth, does the
S meter deflect at all?

4. If no s meter deflection, note the receiver audio output voltage.

5. What is the ratio of the voltage at 4 to the voltage at 3? If it is
more than about 3:1, you have achieved nearly as good a S/N ratio as is
possible.

Owen

Owen Duffy wrote:

Tony Giacometti wrote in
news:suednRqSYJd58aLanZ2dnUVZ_uDinZ2d@hawaiiantel. net:

also, if these loops don't work then why do these designs exist?

Tony,

A few questions:

1. With a 50 load on the preamp input, when tuned to a quiet spot in the
band, RF gain full, preamps on, telephony bandwidth, does the S meter
deflect at all?


not noticeable



2. If no s meter deflection, note the receiver audio output voltage.

125mv


3. With the loop connected on the preamp input, when tuned to a quiet
spot in the band, RF gain full, preamps on, telephony bandwidth, does the
S meter deflect at all?


not noticeable



4. If no s meter deflection, note the receiver audio output voltage.

150mv


5. What is the ratio of the voltage at 4 to the voltage at 3? If it is
more than about 3:1, you have achieved nearly as good a S/N ratio as is
possible.

Owen

Tony Giacometti wrote in
news:A5SdnQdv8vz466LanZ2dnUVZ_t2inZ2d@hawaiiantel. net:

Owen Duffy wrote:

Tony Giacometti wrote in
news:suednRqSYJd58aLanZ2dnUVZ_uDinZ2d@hawaiiantel. net:

also, if these loops don't work then why do these designs exist?

Tony,

A few questions:

1. With a 50 load on the preamp input, when tuned to a quiet spot in
the band, RF gain full, preamps on, telephony bandwidth, does the S
meter deflect at all?


not noticeable



2. If no s meter deflection, note the receiver audio output voltage.

125mv


3. With the loop connected on the preamp input, when tuned to a quiet
spot in the band, RF gain full, preamps on, telephony bandwidth, does
the S meter deflect at all?


not noticeable



4. If no s meter deflection, note the receiver audio output voltage.

150mv


5. What is the ratio of the voltage at 4 to the voltage at 3? If it
is more than about 3:1, you have achieved nearly as good a S/N ratio
as is possible.

So, the ratio is 1.2.

Two thirds (actually 1/1.2^2) of your total noise is from the receiver
internal noise. That is not a good situation, S/N on signals will be
degraded by relatively excessive contribution from the receiver, actually
caused by inadequate antenna gain.

Expected ambient noise level from a lossless antenna in 2kHz at 3.6MHz
should be around -82.9+33dBm or -49.9dBm. The 80m loop gain is about -
47dBi, so expected receive level would be -97dBm which is some 40dB above
your receiver noise floor.

Things aren't working like they should, so you need to localise the
problem.

I have no idea of the sensitivity or bandwidth of your receiver, but a
good (not outstanding, just good) (bare) receiver with a noise floor of -
130dBm should see a large increase in noise moving from dummy load to the
loop. (Ambient at -97dBm would be equivalent to S5 if your S meter was
accurate.)

Just for verification, I performed the same test you did, but with a
600mm a side untuned loop and an ICR20 receiver, and I got a 10 fold
increase in noise from the loop compared to the dummy load. Your loop is
larger and tuned, so it should be a 10dB more sensitive.

BTW, I didn't state it, but those noise measurements MUST be made in SSB
mode.

Owen

On Sat, 17 Nov 2007 12:38:11 -1000, Tony Giacometti
wrote:

OK, other than leveling all existing structures within 2,500 ft of my house
and burying the power lines, how do I solve this problem?

also, if these loops don't work then why do these designs exist?

-sigh-

Tony, if "loops don't work" is the only message you've gotten to this
point, it is the wrong message.

Certainly your loop doesn't work - or at least I have to take your
word for it. That is a far different issue.

Loops do work if you follow standard practices.

The real question is:
"Is a loop my solution?"
and with that comes the $64,000 prize.

In other correspondence you describe noise levels pushing the S-Meter
to S9. If that noise is coming from one direction, a dipole or loop
can solve it. If it is general (meaning that your neighbor's fish
tank heater is bathing you in noise), then you don't stand a chance.

You don't need an antenna, yet. You need to find the source of noise.

73's
Richard Clark, KB7QHC

"Richard Clark" wrote in message
...
On Sat, 17 Nov 2007 10:30:06 -1000, Tony Giacometti
wrote:

Richard, I use a vertical antenna, for transmitting its great, does a
fine
job, but for receive, with the noise in the neighborhood, its not the
best
option. I have tried to use an ANC-4 noise reducer but the noise isn't
reduced enough to hear the weaker signals.

Hi Tony,

Leaving that aside for others to comment....

So, what to do, I followed the instructions for building the loop from
W2YR
and KN4LF and from this link
http://www.hard-core-dx.com/nordicdx.../coaxloop.html

There is a world of opportunity in making a mistake with this monster.
It goes a long way to do something difficult that could be done vastly
easier.

As I wrote previous I have 2 good preamps but the signals are still very
weak.

You state that there is no gap.

No, he said there was a gap. Read it again.