"Richard Clark" wrote in message
...
On Sat, 19 Jan 2008 09:22:43 GMT, "Lee"
wrote:

Yes, I already have a 3ft dia magloop 3-30megs

also a 5ft square magloop for 14-80megs

Typo should read - magloop for 14 - 3.5megs ( can go lower at higher `Q` )

..... both cover the 14meg band....


they work extremely well. and as they are virtually noiseles i hear
stations that can`t be heard on a regular wideband antenna
due to a better sn ratio, albeit, at reduced signal strength.....also,
unfortunately, with reduced transmission levels.....
( very good listening antennas ).

Hi Len (Lee?),

Len, Lee Leon Leonard or Leonardo .....no problem as the birth name is
Leonard...

Are these commercial loops with substantial conductors (well beyond
what would be called wire)?

HOMEBREW!!! .....3ft dia loop, ( 10 ft circumference ) 3/8" tube -
can be persuaded to 80meters ....
HOMEBREW!!! ......5`.0" square ( 20ft circumference ) loop 3/4" tube -
can persuade it to 160meters.

If so, then pushing them into 80M is

No problem....80meters isn`t the problem ! - they work!

going to be a trick unless the 3-30MHz model in fact works.

It works well in the design freq of 3 - 30 megs....can work lower at higher
`Q`
........higher `Q` not good!

If it does not, it needs more capacitance, and that is going to be a loss
leader if you try to add any.

Agreed.

The only other limitation in the 20M band would be how high are they?

Vertical - ground level for vertically polarised ground wave- with
directivity.
Horizontal - 30ft for horizontal `omni directional` polarization - less
gain
than a straight, horizontal dipole at the same height.

That`s why i need a larger, lower `Q` antenna ....which will also
fit in my garden space to t/x on.....

I like 20 meters a lot running Slowscan, Hampal and Digital Voice.

As far as 20M goes, your garden is long enough for a conventional
dipole - provided you have the support, and the direction favors your
need. If not, it seems unlikely you will gain anything over the
magloops.

(Go for more height.)

If you read the o/p, you wouldn`t question everything i have already
stated Richard!!!

I don`t want a fixed dipole at low height!! i want a rotary dipole on the
top
of my tower (mast)....i am aware i can fit a 33foot fixed, wire dipole into
a
35foot garden, lengthwise, but the length of my garden runs east/west so the
dipole would fire north/south - not good...... the magloops receive very
well,
with lower noise than a regular antenna, i can hear stations i wouldn`t
normally
hear on a regular antenna, plus, a horizontal dipole, generally, has more
gain
than a horizontal omni magloop at the same height but is a noisier r/x than
the
magloop, which makes the dipole better for t/x mode....Yes?...
My garden is 14ft wide and a 14meg dipole is 33ft+, i don`t want my
neighbours
complaining when half the antenna is over their garden when i`m working east
west...hence linear loading the dipole...to shorten it!!

All i requested was a suitable design configuration for a linear loaded
halfsize
rotary dipole to go on top of the tower and my reasons why.......
not a discussion on magloops ....

I`ll go with the linear short 1/4 wave vertical layout for each leg of the
dipole,
where half the element is fed back on itself down to 6 inches from the
ground
( or, in my case, to the mast ) with about 3 inch spacing of the element.

Regards.

Len ....( Lee, Leon Leonard Leonardo ).........G6ZSG....