Lee wrote:

"Irv Finkleman" wrote in message
...
Lee wrote:

"Reg Edwards" wrote in message
...
==============================
There's almost certainly nothing the matter with it.

You can't expect a small QRP magloop to work as well as a 1/2-wave
vertical with 100 watts.

What makes you think it is not working as well as it ought to? What
have you compared it with?
----
Reg, G4FGQ

Hello Reg..
Took your advice and built a magloop......
I`m comparing the magloop to 5watts on a half-size sloping G5RV and i
find
the magloop equivalent to the G5RV on R/X.whilst the magloop is inside
the
house!!!..
I have a friend about a mile away that i chat to who hears me on the
G5RV at
s30+ ......but, not at all on the magloop!!!!......
Why am i not being heard on the magloop???? :-/.
H-E-L-P........

Lee.....G6ZSG.....

You may have the null pointed at him.
Tried that just and got 5x8 with magloop in the house!!!! and only
5watts....

Lee....G6ZSG..

Figured as much. You might want to try the loop in a horizontal configuration
for omnidirectional work. You'll probably find that you can operate it horizontally
just a few inches above the ground although I recommend a couple feet.

Irv VE6BP


--
--------------------------------------
Diagnosed Type II Diabetes March 5 2001
Beating it with diet and exercise!
297/215/210 (to be revised lower)
58"/43"(!)/44" (already lower too!)
--------------------------------------
Visit my HomePage at http://members.shaw.ca/finkirv/index.html
Visit my Baby Sofia website at http://members.shaw.ca/finkirv4/index.htm
Visit my OLDTIMERS website at http://members.shaw.ca/finkirv5/index.htm
--------------------
Irv Finkleman,
Grampa/Ex-Navy/Old Fart/Ham Radio VE6BP
Calgary, Alberta, Canada

I second what Irv (VE6BP) has suggested. The modeling that I have done of
small loops (just plain loops, no magnetic materials involved) placed
horizontally (above earth) suggest the same pattern in all directions with a
significant dip towards the zenith - just what one's receiver likes in order
to receive signals from far away.

73 Mac N8TT

--
J. Mc Laughlin; Michigan U.S.A.
Home:
"Irv Finkleman" wrote in message
...
Lee wrote:

"Irv Finkleman" wrote in message
...
Lee wrote:

"Reg Edwards" wrote in message
...
==============================
There's almost certainly nothing the matter with it.

You can't expect a small QRP magloop to work as well as a 1/2-wave
vertical with 100 watts.

What makes you think it is not working as well as it ought to?
What
have you compared it with?
----
Reg, G4FGQ

Hello Reg..
Took your advice and built a magloop......
I`m comparing the magloop to 5watts on a half-size sloping G5RV and
i
find
the magloop equivalent to the G5RV on R/X.whilst the magloop is
inside
the
house!!!..
I have a friend about a mile away that i chat to who hears me on the
G5RV at
s30+ ......but, not at all on the magloop!!!!......
Why am i not being heard on the magloop???? :-/.
H-E-L-P........

Lee.....G6ZSG.....

You may have the null pointed at him.
Tried that just and got 5x8 with magloop in the house!!!! and only
5watts....

Lee....G6ZSG..

Figured as much. You might want to try the loop in a horizontal
configuration
for omnidirectional work. You'll probably find that you can operate it
horizontally
just a few inches above the ground although I recommend a couple feet.

Irv VE6BP


--
--------------------------------------
Diagnosed Type II Diabetes March 5 2001
Beating it with diet and exercise!
297/215/210 (to be revised lower)
58"/43"(!)/44" (already lower too!)
--------------------------------------
Visit my HomePage at http://members.shaw.ca/finkirv/index.html
Visit my Baby Sofia website at http://members.shaw.ca/finkirv4/index.htm
Visit my OLDTIMERS website at http://members.shaw.ca/finkirv5/index.htm
--------------------
Irv Finkleman,
Grampa/Ex-Navy/Old Fart/Ham Radio VE6BP
Calgary, Alberta, Canada

"J. Mc Laughlin" wrote in message
...
I second what Irv (VE6BP) has suggested. The modeling that I have done of
small loops (just plain loops, no magnetic materials involved) placed
horizontally (above earth) suggest the same pattern in all directions with
a
significant dip towards the zenith - just what one's receiver likes in
order
to receive signals from far away.

73 Mac N8TT

--
J. Mc Laughlin; Michigan U.S.A.
Home:
"Irv Finkleman" wrote in message
...
Lee wrote:


I`ll try that Mac and see if it is worth the effort of a much larger
project.... like 10ft square multiband!!.

Thanks Mac & Irv..

Lee....G6ZSG......

Lee,

Using the loop indoors, at ground-floor level, at 20MHz, on a
groundwave path, is not inconsistent with what you get. Get it
high-up, outdoors, and it will make a big difference.

The capacitor is made from a length of coax. I wonder how long it is
and how it is located relative to the loop? Wherever it is, being
unbalanced coax it will unbalance the loop.

But what worries me, the very thin coaxial inner conductor is in
series with the main loop conductor. It may have a loss resistance
several times greater than the large diameter main loop. You could be
losing a lot of decibels.
----
Reg, G4FGQ.

But what worries me, the very thin coaxial inner conductor is in
series with the main loop conductor. It may have a loss resistance
several times greater than the large diameter main loop. You could
be losing a lot of decibels.

=====================================
Lee,

If you cut the length of coax into, say, 7 equal lengths and connected
them in parallel you will have a capacitor of the same value but with
a loss resistance only 1/7th of the single length.

More compact too. 6 fit very nicely round 1. Bundle them up in a
plastic bag to keep off the rain.
----
Reg, G4FGQ.

"Reg Edwards" wrote in message
...


Lee,

If you cut the length of coax into, say, 7 equal lengths and connected
them in parallel you will have a capacitor of the same value but with
a loss resistance only 1/7th of the single length.

RG8 / UR213 would be more convenient i should think Reg if i were running a
bit more QRO......

More compact too. 6 fit very nicely round 1. Bundle them up in a
plastic bag to keep off the rain.

I`ll try that Reg..... i have an old QRP atu with air spaced variables
around 350pf with slow motion drive i could use on a more ambitious project
a little later....good for 100watts or so SSB...Yes?

Lee...G6ZSG.......

"Reg Edwards" wrote in message
...
Lee,

Using the loop indoors, at ground-floor level, at 20MHz, on a
groundwave path, is not inconsistent with what you get. Get it
high-up, outdoors, and it will make a big difference.

Next, after testing 2` above ground.......

The capacitor is made from a length of coax. I wonder how long it is
and how it is located relative to the loop? Wherever it is, being
unbalanced coax it will unbalance the loop.

Isn`t a variable butterfly vane capacitor unbalanced also as is the co-axial
trimpot and the compression piston cap?..they are all used on magloops Reg.

But what worries me, the very thin coaxial inner conductor is in
series with the main loop conductor. It may have a loss resistance
several times greater than the large diameter main loop. You could be
losing a lot of decibels.

I`m listening

Lee....G6ZSG.....

Dear Lee (G6ZSG):
Please do note that I was commenting on a receiving antenna, which is in
need of an antenna mounted amplifier. The amplifier does not have
hard-to-accomplish requirements for gain (20 db is good) or for input
impedance. However, the amplifier does need to have very high IM
performance and at least a high-pass filter to reject signals from the AM
broadcast band.

Using a small, horizontal loop antenna as a transmitting antenna can be
done. As you are finding out, coupling power into the loop is a challenge.

Good luck. 73 Mac N8TT
--
J. Mc Laughlin; Michigan U.S.A.
Home:
"Lee" wrote in message
k...

"J. Mc Laughlin" wrote in message
...
I second what Irv (VE6BP) has suggested. The modeling that I have done
of
small loops (just plain loops, no magnetic materials involved) placed
horizontally (above earth) suggest the same pattern in all directions
with
a
significant dip towards the zenith - just what one's receiver likes in
order
to receive signals from far away.

73 Mac N8TT

--
J. Mc Laughlin; Michigan U.S.A.
Home:
"Irv Finkleman" wrote in message
...
Lee wrote:


I`ll try that Mac and see if it is worth the effort of a much larger
project.... like 10ft square multiband!!.

Thanks Mac & Irv..

Lee....G6ZSG......

The intermod performance of a receiving pre-amplifier is of no
consequence with a magloop.

The Q and selectivity (of the order of 1000) of the loop at the wanted
frequency easily reject local high-power MF broadcast frequencies.

On 160m, It's difficult to hear any stations only 3 kHz away from the
wanted frequency.
----
Reg.

"Reg Edwards" wrote in message
...
The intermod performance of a receiving pre-amplifier is of no
consequence with a magloop.

The Q and selectivity (of the order of 1000) of the loop at the wanted
frequency easily reject local high-power MF broadcast frequencies.

On 160m, It's difficult to hear any stations only 3 kHz away from the
wanted frequency.
----
Reg.


Hi Reg....

I took my little 1 meter dia ( 10 ft circ ) loop outside lunchtime and
mounted it verticaly 2ft off the lawn and tested it, not expecting anything
special and found that comparing it to the G5RV that there was no noticable
difference between the two!!...my friend and i switched out our preamps and
attenuator in.

I even turned the loop face on and edge on with a change of 2-3 S points..
So, needless to say, i am rather impressed with the performance and
bandwidth of 2:1 SWR about 180k.....so much so that i am thinking seriously
of going for a 20 ft circumference or larger for 80 and 40 metres....

Regards.

Lee....G6ZSG.....Well impressed!!! :-)