On May 3, 3:02*pm, "Clive" wrote:
How laughable.

Who buys into the whole "active antenna" thing? Some of my best SWLing has
been with a 5 or 6 foot hunk of wire laying on the floor.

Put your effort into a getting a good alignment. That will do you far better
than these red herring gadgets that are just like a shiny lure to a sucker.

"Clive" wrote in message
m...

How laughable.

Who buys into the whole "active antenna" thing? Some of my best SWLing has
been with a 5 or 6 foot hunk of wire laying on the floor.

Put your effort into a getting a good alignment. That will do you far
better than these red herring gadgets that are just like a shiny lure to a
sucker.

When you amplify, you amplify EVERYTHING...noise, distortion and often
these gadgets inject products into the mixer that screw up your IF
tracking, reducing the inherent performance of your receiver.

Quit looking for a "magic pill" and get back to basics: 1. Good alignment.
2. Wire antenna in unobstructed free space.

That's all you need.




You're basically right that the TinyTenna can't achieve miracles.

But what do you mean (or think you mean) by
a) Alignment.
b) IF Tracking.

There are more complex kinds of active antenna that can, to some extent,
help you fight against local interference.

--

Brian Gregory. (In the UK)

To email me remove the letter vee.

On 5/4/10 05:03 , Brian Gregory [UK] wrote:
wrote in message
m...

How laughable.

Who buys into the whole "active antenna" thing? Some of my best SWLing has
been with a 5 or 6 foot hunk of wire laying on the floor.

Put your effort into a getting a good alignment. That will do you far
better than these red herring gadgets that are just like a shiny lure to a
sucker.

When you amplify, you amplify EVERYTHING...noise, distortion and often
these gadgets inject products into the mixer that screw up your IF
tracking, reducing the inherent performance of your receiver.

Quit looking for a "magic pill" and get back to basics: 1. Good alignment.
2. Wire antenna in unobstructed free space.

That's all you need.




You're basically right that the TinyTenna can't achieve miracles.

But what do you mean (or think you mean) by
a) Alignment.
b) IF Tracking.


A series of tuned circuits, such as those found in a
superheterodyne receiver are said to be in alignment when all paths
are tuned to the correct frequencies. Correct alignment raises
output of desired signals, while reducing noise floor. A receiver in
proper adjustment-- proper alignment -- will perform often
remarkably better on the same antenna, in the same location as the
same model receiver out of alignment. Often by only a very small
amount.

IF tracking is the property of two variable tuned circuits to
produce a single output frequency across their entire range.

Forgive me if this is something you already know. A gross
oversimplification, here, if you don't, will explain.

IF, or intermediary frequency, is a property of a superheterodyne
receiver that improves selectivity, improves rejection of undesired
signals, and produces a single, easily manageable signal for
detection. IF is produced by mixing the incoming desired signal with
a locally generated signal of a frequency above the desired signal
that is a fixed difference from the desired incoming signal.

By mixing these two frequencies, the intermediary frequency is
generated the frequency of which is the exact difference between the
incoming and the locally generated frequency. There is also a
frequency generated that is the sum of the two mixed frequencies,
but that is rejected by the tuned intermediary frequency circuits
which are tuned to a single fixed frequency.

In order for the intermediary frequency to pass through the tuned
IF circuits, the intermediary frequency needs to be the same as one
tunes incoming signals across the dial. That means that the mix
frequency needs to vary along with the incoming frequency to remain
precisely higher than the incoming frequecy by the amount of the IF.
This is referred to as tracking. One signal tracks the other to
retain the proper relationship as the tuning dial is moved.

Implements, like the Tiny Tenna, in some inexpensive receivers,
can, if overloaded, produce their own mix frequencies that, in turn
mix with incoming and locally generated frequencies to yield un
expected mix products that produce variations in the intermediary
frequency. In some receivers, a very strong signal alone can cause
the IF to shift.

So, what the poster was referring to is proper adjustment of
tuned circuits within the receiver, and the injection of instability
by frequencies created by cheap active antennae disturbing the
frequencies that must pass through those tuned circuits.

Again, apologies, if your technical understanding exceeds these
oversimplified descriptions.

Arky Bob wrote:
Anybody here use the tiny-tenna?

Is it any good?

Two instances where an active antenna comes in handy a

1. "Portable" use - I have a milspec preamp and a 3m whip I use with my
AOR 7030+ for camping and vacations. I can set everything up in 5
minutes.

2. If the neighbors generate a lot of RFI, an active antenna placed as
far from RFI sources as possible might make sense. RFI goes down as a
square of the distance, so if you can have your antenna twice as far
from a noise source, the rfi will go down by a factor of 4. In that
case, while the active antenna will amplify noise as well as the signal,
you're still getting a signal to noise improvement.

I have one of those too - a 65' random wire that feeds a preamp, and the
coax runs underground in a pipe that comes back to the house. There,
the preamp is mostly to compensate for the signal loss of a few hundred
feet of coax.

The tiny-tenna does "work", but it's a very simple circuit you could
make yourself with parts from Radio Shaft. Unless you've got a
soldering iron and at least some of the parts on hand it's not apt to
cost less than buying the ready made one. The Tiny Tenna guy is
probably making about $10 an hour after you figure in all the expenses
of making a product and running a business.

Milspec preamps are very well made and can often be found on eBay at a
fraction of what they sold for new. ($40 is typical) Brands to look
for include Avantek, Anzac, Watkins Johnson, Norlin, Aiken, & Applied
Communications. (the last 3 are really the same company - they changed
names often) Years ago I tried an Ar2 preamp and it worked well, but
died young. The milspec ones are much more robust.

But the place to start is identifying what the problems are with your
current antenna, and thinking about ways to solve those problems. You
can accomplish a lot with wire, coax or ladder line, and an impedance
matching transformer.

Yeah. Ok. Whatever.

Go ahead and convince yourselves the money you spend on this stuff is worth
it.

Alignment is not rocket science. A piece of wire strung in the open air is
what they
used during the Depression for Pete's sake. Don't make this out to be more
complicated than it needs to be.

On May 4, 8:47*am, "Clive" wrote:
Yeah. Ok. Whatever.

Go ahead and convince yourselves the money you spend on this stuff is worth
it.

Alignment is not rocket science. A piece of wire strung in the open air is
what they
used during the Depression for Pete's sake. Don't make this out to be more
complicated than it needs to be.

Lot less RFI during the Depression.

"D. Peter Maus" wrote in message
...
On 5/4/10 05:03 , Brian Gregory [UK] wrote:
wrote in message
m...

How laughable.

Who buys into the whole "active antenna" thing? Some of my best SWLing
has
been with a 5 or 6 foot hunk of wire laying on the floor.

Put your effort into a getting a good alignment. That will do you far
better than these red herring gadgets that are just like a shiny lure to
a
sucker.

When you amplify, you amplify EVERYTHING...noise, distortion and often
these gadgets inject products into the mixer that screw up your IF
tracking, reducing the inherent performance of your receiver.

Quit looking for a "magic pill" and get back to basics: 1. Good
alignment.
2. Wire antenna in unobstructed free space.

That's all you need.




You're basically right that the TinyTenna can't achieve miracles.

But what do you mean (or think you mean) by
a) Alignment.
b) IF Tracking.


A series of tuned circuits, such as those found in a superheterodyne
receiver are said to be in alignment when all paths are tuned to the
correct frequencies. Correct alignment raises output of desired signals,
while reducing noise floor. A receiver in proper adjustment-- proper
alignment -- will perform often remarkably better on the same antenna, in
the same location as the same model receiver out of alignment. Often by
only a very small amount.

IF tracking is the property of two variable tuned circuits to produce a
single output frequency across their entire range.

Do you mean the ability of the RF tuned and local oscillator tuned circuits
to stay separated by exactly the IF frequency?
That's just part of alignment.


Forgive me if this is something you already know. A gross
oversimplification, here, if you don't, will explain.

IF, or intermediary frequency, is a property of a superheterodyne
receiver that improves selectivity, improves rejection of undesired
signals, and produces a single, easily manageable signal for detection. IF
is produced by mixing the incoming desired signal with a locally generated
signal of a frequency above the desired signal that is a fixed difference
from the desired incoming signal.

By mixing these two frequencies, the intermediary frequency is generated
the frequency of which is the exact difference between the incoming and
the locally generated frequency. There is also a frequency generated that
is the sum of the two mixed frequencies, but that is rejected by the tuned
intermediary frequency circuits which are tuned to a single fixed
frequency.

In order for the intermediary frequency to pass through the tuned IF
circuits, the intermediary frequency needs to be the same as one tunes
incoming signals across the dial. That means that the mix frequency needs
to vary along with the incoming frequency to remain precisely higher than
the incoming frequecy by the amount of the IF. This is referred to as
tracking. One signal tracks the other to retain the proper relationship as
the tuning dial is moved.

Implements, like the Tiny Tenna, in some inexpensive receivers, can, if
overloaded, produce their own mix frequencies that, in turn mix with
incoming and locally generated frequencies to yield un expected mix
products that produce variations in the intermediary frequency. In some
receivers, a very strong signal alone can cause the IF to shift.

Maybe in a really ancient receiver. In all my receivers the local
oscillators are either crystal controlled or locked by PLL to crystal
controlled references.


So, what the poster was referring to is proper adjustment of tuned
circuits within the receiver, and the injection of instability by
frequencies created by cheap active antennae disturbing the frequencies
that must pass through those tuned circuits.

Again, apologies, if your technical understanding exceeds these
oversimplified descriptions.

A good modern receiver will stay adequately in alignment unless it's been
fiddled with, all the important selectivity will be in crystal or ceramic
filters anyway.

Alignment and IF tracking seem like really weird things to quote as
important nowadays.

They might help improve sensitivity, and reduce intermodulation problems but
other things like adding a preselector will produce more exciting results.

--

Brian Gregory. (In the UK)

To email me remove the letter vee.

On 5/4/10 13:28 , Brian Gregory [UK] wrote:
"D. Peter wrote in message
...
On 5/4/10 05:03 , Brian Gregory [UK] wrote:
wrote in message
m...

How laughable.

Who buys into the whole "active antenna" thing? Some of my best SWLing
has
been with a 5 or 6 foot hunk of wire laying on the floor.

Put your effort into a getting a good alignment. That will do you far
better than these red herring gadgets that are just like a shiny lure to
a
sucker.

When you amplify, you amplify EVERYTHING...noise, distortion and often
these gadgets inject products into the mixer that screw up your IF
tracking, reducing the inherent performance of your receiver.

Quit looking for a "magic pill" and get back to basics: 1. Good
alignment.
2. Wire antenna in unobstructed free space.

That's all you need.




You're basically right that the TinyTenna can't achieve miracles.

But what do you mean (or think you mean) by
a) Alignment.
b) IF Tracking.


A series of tuned circuits, such as those found in a superheterodyne
receiver are said to be in alignment when all paths are tuned to the
correct frequencies. Correct alignment raises output of desired signals,
while reducing noise floor. A receiver in proper adjustment-- proper
alignment -- will perform often remarkably better on the same antenna, in
the same location as the same model receiver out of alignment. Often by
only a very small amount.

IF tracking is the property of two variable tuned circuits to produce a
single output frequency across their entire range.

Do you mean the ability of the RF tuned and local oscillator tuned circuits
to stay separated by exactly the IF frequency?
That's just part of alignment.


Yes, on both counts. I did say it was an oversimplification for
those without the technical understanding.



Forgive me if this is something you already know. A gross
oversimplification, here, if you don't, will explain.

IF, or intermediary frequency, is a property of a superheterodyne
receiver that improves selectivity, improves rejection of undesired
signals, and produces a single, easily manageable signal for detection. IF
is produced by mixing the incoming desired signal with a locally generated
signal of a frequency above the desired signal that is a fixed difference
from the desired incoming signal.

By mixing these two frequencies, the intermediary frequency is generated
the frequency of which is the exact difference between the incoming and
the locally generated frequency. There is also a frequency generated that
is the sum of the two mixed frequencies, but that is rejected by the tuned
intermediary frequency circuits which are tuned to a single fixed
frequency.

In order for the intermediary frequency to pass through the tuned IF
circuits, the intermediary frequency needs to be the same as one tunes
incoming signals across the dial. That means that the mix frequency needs
to vary along with the incoming frequency to remain precisely higher than
the incoming frequecy by the amount of the IF. This is referred to as
tracking. One signal tracks the other to retain the proper relationship as
the tuning dial is moved.

Implements, like the Tiny Tenna, in some inexpensive receivers, can, if
overloaded, produce their own mix frequencies that, in turn mix with
incoming and locally generated frequencies to yield un expected mix
products that produce variations in the intermediary frequency. In some
receivers, a very strong signal alone can cause the IF to shift.

Maybe in a really ancient receiver. In all my receivers the local
oscillators are either crystal controlled or locked by PLL to crystal
controlled references.


Many of mine, as well, yes. But there are those, even today which
are not so.




So, what the poster was referring to is proper adjustment of tuned
circuits within the receiver, and the injection of instability by
frequencies created by cheap active antennae disturbing the frequencies
that must pass through those tuned circuits.

Again, apologies, if your technical understanding exceeds these
oversimplified descriptions.

A good modern receiver will stay adequately in alignment unless it's been
fiddled with, all the important selectivity will be in crystal or ceramic
filters anyway.

Alignment and IF tracking seem like really weird things to quote as
important nowadays.

They might help improve sensitivity, and reduce intermodulation problems but
other things like adding a preselector will produce more exciting results.


The original poster's point is that with a properly aligned
receiver, one begins with an optimized platform that will respond to
less complex configurations with more satisfactory results. Better
performance, lower cost, on the same radio.

My personal choices include preselectors, and a variety of
antennae, active and passive.

On May 1, 9:18*pm, Arky Bob wrote:
Anybody here use the tiny-tenna?

Is it any good?

Arky Bob,

Build your own 1-Transistor Active Antenna
http://www.dxzone.com/cgi-bin/dir/jump2.cgi?ID=7550
http://www.ee.washington.edu/circuit...activeant.html
http://circuitdiagram.net/active-radio-antenna.html

TIP - Mount the Whip {Antenna Element} and
Amplifier outside a Window at 45* like a Flag Pole.

Coax Cable to Radio with Speaker Wire for
power leads to a Switch & Battery near the
SWL Radio.

Better a make your own 2-Transistor Active Antenna
http://www.dxzone.com/cgi-bin/dir/jump2.cgi?ID=22731
http://www.dxzone.com/cgi-bin/dir/jump2.cgi?ID=16539
http://www.qrp.pops.net/probe1.asp

Fancier "Tuned Active Antenna for 5 to 22 MHz
http://www.hard-core-dx.com/nordicdx.../swactive.html

SWL -Newbies- Beyond the "Tiny-Tenna"
* DIY- Active Antenna Kits and a lot more . . .
http://groups.google.com/group/rec.r...d90a539eb30f90

TSE - Instead of a Short (18"~39"} Whip Antenna
Use a Mini 12"16" Hula-Hoop as a Frame for a
piece of 300 Ohm Twin-Lead [TL] taped all the way
around it. On one end {left-side} use one wire
of the TL going CW, and on the other end {right-side}
use the other wire of the TL going CCW. This gives
you two parallel wires that are equal and opposite
that act as a circular-dipole. This Mini-Loop-Dipole
Antenna Element can then be both 'rotated' and
'positioned' to reduce your local noise pick-up.

hope this helps a 'tiny-tenna' itty-bitty - iane ~ RHF