Wellbrook question
 

Has anyone had a "bad", as in less then stellar performance, with a
Wellbrook ALA 1530
loop antenna?

Given the almost sacred refference the Wellbrook is held in I have
debated asking
this question. I have a ALA 1530 that is part of a trade that I am
looking at and
guys I just don't get it. This antenna is reputed to be the cat's meow,
but I have
found it marginal at best. A north country active antenna is nearly
it's match
and the 3rd harmonic of a local MW (770KHz) is S3 on the Wellbrook. A
Lankford Active Dipole stomps it in gain, IP2 and IP3 and for
directivity.

I am wondering if this antenna is defective or if it is a case of the
Emperors New
Clothes. I have tried loops several times in the last 30 years and
always give up
becuase I have never found the reported imunity against local QRM to be
true.
I am building a copy of the WL1030 (http://wl1030.com/), but I don't
understand
the fascination with loops. What am I missing?

For MW DX "big" air loops make sense. Good directivity to null out an
offending
signal. I notice Ron Harding uses McKay 100E with a phaser to achieve
good
nulls. For HF the sky wave "smears" both the desired and unwanted
signals
making a null very iffy.

Receivers used in this test:
R2000
R8B
R390
R392
The R390 and R392 where not tested at my home but at a friend's home
where I have them stored. While I like both the R390 and R392, they are
somewhat awkward to rapidly tune from one frequency to a wildly
seperated
one.

Terry

Wellbrook question
 

In article .com,
wrote:

Has anyone had a "bad", as in less then stellar performance, with a
Wellbrook ALA 1530 loop antenna?

Given the almost sacred refference the Wellbrook is held in I have
debated asking this question. I have a ALA 1530 that is part of a
trade that I am looking at and guys I just don't get it. This antenna
is reputed to be the cat's meow, but I have found it marginal at
best. A north country active antenna is nearly it's match and the 3rd
harmonic of a local MW (770KHz) is S3 on the Wellbrook. A Lankford
Active Dipole stomps it in gain, IP2 and IP3 and for directivity.

I am wondering if this antenna is defective or if it is a case of the
Emperors New Clothes. I have tried loops several times in the last 30
years and always give up becuase I have never found the reported
imunity against local QRM to be true. I am building a copy of the
WL1030 (http://wl1030.com/), but I don't understand the fascination
with loops. What am I missing?

For MW DX "big" air loops make sense. Good directivity to null out an
offending signal. I notice Ron Harding uses McKay 100E with a phaser
to achieve good nulls. For HF the sky wave "smears" both the desired
and unwanted signals making a null very iffy.


Receivers used in this test:
R2000
R8B
R390
R392
The R390 and R392 where not tested at my home but at a friend's home
where I have them stored. While I like both the R390 and R392, they
are somewhat awkward to rapidly tune from one frequency to a wildly
seperated one.

I don't know what to tell you about your experience with loop antennas.
My experience and many others is contrary to yours. Loop antennas are
not a fascination just a good design. I've never used the Wellbrook
antennas so I don't know the construction details. Maybe the antenna is
not constructed properly.

Your complaint about IP2 and IP3 concerns the amplifier design not the
antenna design.

--
Telamon
Ventura, California

Wellbrook question
 

wrote:
Has anyone had a "bad", as in less then stellar performance, with a
Wellbrook ALA 1530
loop antenna?

Given the almost sacred refference the Wellbrook is held in I have
debated asking
this question. I have a ALA 1530 that is part of a trade that I am
looking at and
guys I just don't get it. This antenna is reputed to be the cat's meow,
but I have
found it marginal at best. A north country active antenna is nearly
it's match
and the 3rd harmonic of a local MW (770KHz) is S3 on the Wellbrook. A
Lankford Active Dipole stomps it in gain, IP2 and IP3 and for
directivity.

I am wondering if this antenna is defective or if it is a case of the
Emperors New
Clothes. I have tried loops several times in the last 30 years and
always give up
becuase I have never found the reported imunity against local QRM to be
true.
I am building a copy of the WL1030 (http://wl1030.com/), but I don't
understand
the fascination with loops. What am I missing?

For MW DX "big" air loops make sense. Good directivity to null out an
offending
signal. I notice Ron Harding uses McKay 100E with a phaser to achieve
good
nulls. For HF the sky wave "smears" both the desired and unwanted
signals
making a null very iffy.

Receivers used in this test:
R2000
R8B
R390
R392
The R390 and R392 where not tested at my home but at a friend's home
where I have them stored. While I like both the R390 and R392, they are
somewhat awkward to rapidly tune from one frequency to a wildly
seperated
one.

Terry

One thing you might do is check the cables connecting the different
components of the Wellbrook. At one point I noticed that my loop wasn't
performing as I thought it should and I discovered that the cable
connecting the receiver to the antenna interface had a poor connection
where it meets the interface box. The intermittent connection became
obvious as soon as I jiggled the cable a bit.

Also, where do you have the loop situated? In my experience the
performance of the loop is seriously degraded when used indoors.

Wellbrook question
 

Has anyone had a "bad", as in less then stellar performance, with a
Wellbrook ALA 1530
loop antenna?

Hi Terry,

I have a homebrew version of the Wellbrook shielded loop 7' in diameter. It
is in my woods on a short tower and rotator.
On 160M and 75M it is the same as my 80M inverted vee. It's a good performer
on MW/LW but not any real difference between it and a homebrew voltage probe
antenna with a 4' whip.

Loops are most useful where there is a single noise source that can be
nulled with the loop- other than that, it's a toss up.
There is still the wive's tale making the rounds that shielded loop are
immune to the E field noise - rubbish and well disproven in the literature.

So, in summary, I like mine for being a compact RX antenna for MW/LW, but at
least in my environment, not sure I would go to the trouble next time.

Dale W4OP
for PAR Electronics, Inc.

Wellbrook question
 

Steve wrote:


One thing you might do is check the cables connecting the different
components of the Wellbrook. At one point I noticed that my loop wasn't
performing as I thought it should and I discovered that the cable
connecting the receiver to the antenna interface had a poor connection
where it meets the interface box. The intermittent connection became
obvious as soon as I jiggled the cable a bit.

Also, where do you have the loop situated? In my experience the
performance of the loop is seriously degraded when used indoors.

Calbe and connectors are good, and have been used to power
the Lankford active dipole I am checking.

I have tried it in a variety of locations.

We even went so far as to drive to the Red River Gorge, an area well
away
from houses, power lines etc.

The preformance just doesn't strike me as being worth the fairly high
cost.

The active dipole beat it every time.

Terry

Wellbrook question
 

Dale Parfitt wrote:
Has anyone had a "bad", as in less then stellar performance, with a
Wellbrook ALA 1530
loop antenna?

Hi Terry,

I have a homebrew version of the Wellbrook shielded loop 7' in diameter. It
is in my woods on a short tower and rotator.
On 160M and 75M it is the same as my 80M inverted vee. It's a good performer
on MW/LW but not any real difference between it and a homebrew voltage probe
antenna with a 4' whip.

Loops are most useful where there is a single noise source that can be
nulled with the loop- other than that, it's a toss up.
There is still the wive's tale making the rounds that shielded loop are
immune to the E field noise - rubbish and well disproven in the literature.

So, in summary, I like mine for being a compact RX antenna for MW/LW, but at
least in my environment, not sure I would go to the trouble next time.

Dale W4OP
for PAR Electronics, Inc.

I am begining to think that many people over rate a loop because it has
lower over
all gain and therefore is quiter. Based on my experience with improved
detector and
audio chains I have come to understand that the signal to noise is the
only variable
that really matters. I wish my fancy HiFer beacon/test source had not
been fried
by Thor. Even the 13.xxMHz crsytal was toast! It would be interesting
to run some
real experiments to compare antennas the way I compared detectors and
post detection amplifiers.

BTW I have completly ripped out all of my coax and pulled down my
antennas.
Since I got rid of my desktop PC and I have gone to a laptop I found I
really needed
to redesign my radio desk. Since my antennas and coax have been up for
over 15
years, I decided to redo the whole mess.

Fall is a very good time to errect new antennas and I am going to
reroute all my coax
through 1/2" copper tubing that will be bonded to my perimeter ground
ring. An
electrician friend used his mini Ditch Witch to dig me a couple of
trenches. I hope
to have the antennas back up by Monday evening.

I typically research and build devcies in the summer, think about
antennas in teh
fall and do serious listening over the winter.

Terry

Wellbrook question
 

wrote in message
oups.com...

Dale Parfitt wrote:
Has anyone had a "bad", as in less then stellar performance, with a
Wellbrook ALA 1530
loop antenna?

Hi Terry,

I have a homebrew version of the Wellbrook shielded loop 7' in diameter.
It
is in my woods on a short tower and rotator.
On 160M and 75M it is the same as my 80M inverted vee. It's a good
performer
on MW/LW but not any real difference between it and a homebrew voltage
probe
antenna with a 4' whip.

Loops are most useful where there is a single noise source that can be
nulled with the loop- other than that, it's a toss up.
There is still the wive's tale making the rounds that shielded loop are
immune to the E field noise - rubbish and well disproven in the
literature.

So, in summary, I like mine for being a compact RX antenna for MW/LW,
but at
least in my environment, not sure I would go to the trouble next time.

Dale W4OP
for PAR Electronics, Inc.

I am begining to think that many people over rate a loop because it has
lower over
all gain and therefore is quiter. Based on my experience with improved
detector and
audio chains I have come to understand that the signal to noise is the
only variable
that really matters. I wish my fancy HiFer beacon/test source had not
been fried
by Thor. Even the 13.xxMHz crsytal was toast! It would be interesting
to run some
real experiments to compare antennas the way I compared detectors and
post detection amplifiers.

BTW I have completly ripped out all of my coax and pulled down my
antennas.
Since I got rid of my desktop PC and I have gone to a laptop I found I
really needed
to redesign my radio desk. Since my antennas and coax have been up for
over 15
years, I decided to redo the whole mess.

Fall is a very good time to errect new antennas and I am going to
reroute all my coax
through 1/2" copper tubing that will be bonded to my perimeter ground
ring. An
electrician friend used his mini Ditch Witch to dig me a couple of
trenches. I hope
to have the antennas back up by Monday evening.

I typically research and build devcies in the summer, think about
antennas in teh
fall and do serious listening over the winter.

Terry


I'll match your dipole against my 70m full-wave horizontal loop for equal
gain from 70M all they way up to 6M - can you say broadbanded? A dipole is
not.

Wellbrook question
 

Seeing-I-dawg wrote:
I'll match your dipole against my 70m full-wave horizontal loop for equal
gain from 70M all they way up to 6M - can you say broadbanded? A dipole is
not.

Can you rotate your "70M full-wave horizontal loop"?

And at 70M, or about 230 feet in "diameter", it is a very different
antenna
then a 1M much touted miracle loop. I don't think I was attempting to
compare
3' with 230'. One supposed advantage of the small, fractional
wavelength,
loop is the reported, or should I say reputed, highly directional
charactoristics.
That famous figure "8" pattern.

The dipole to which I am reffering is an amplified, very high IP3 and
IP2 unit with
very good,as in flat gain and very directional, from 100KHz to above
28MHz. I will
have to connect it to my scanner and see if I can receive any 6M ham
comms,
or more likely around here older 49MHz telephones. I suspect it will
run out of steam somewhere just above 35MHz, but I haven't checked. It
will be later next week before
I can do any tests as my "shack" is in pieces and I am reduced to a
DX398 coupled
to a ~50 random wire out the kitchen window.

Terry

Wellbrook question
 

I'll match your dipole against my 70m full-wave horizontal loop for equal
gain from 70M all they way up to 6M - can you say broadbanded? A dipole is
not.

Apples and oranges. The current discussion is about electrically small,
rotatable loops.

Dale W4OP

Wellbrook question
 

In article VD8Tg.9636$422.6849@trnddc03,
"Dale Parfitt" wrote:

Snip

There is still the wive's tale making the rounds that shielded loop are
immune to the E field noise - rubbish and well disproven in the literature.

Snip

Old "wives tale" is a rec.radio.amateur.antenna trash talk phrase.

Were have you been reading that an electrically small shielded or
unshielded loop is sensitive to E field?

--
Telamon
Ventura, California