Grove's Flex-tenna
 

It will probally be as dead on arrival as that Tiny-Tenna I wasted about
ten dollars,plus shipping and handling charges on from Mr.Tiny-Tenna
about ten or twelve years ago.
cuhulin

Grove's Flex-tenna
 

Grove ought to send me one to try out for free and I will give out me
expert opinion.Grove pays it all,both ways.Grove,I am getting NOT to
trust y'all anymore.
cuhulin

Grove's Flex-tenna
 

Grove's Flex-tenna
 

Telamon,

I am a Hands-on-Kind-of-Guy
and Seeing-Is-Believing

we'll see ~ RHF

Grove's Flex-tenna
 

Any old thing works fine on modern portable SW's, as far as pulling
in signal. You can't get extravagant or most receivers will overload
with the strong signals around and give you horrible images all over
the band. So the modest wind-up antennas are about the best you can
do.

You get differences in rejection of local noise, and for doing that
you need grounding and matching transformers and distant antennas,
or some ability to steer a null on noise sources at least, to get
away from the local sources somewhat.

So I expect the feature here is invisible wire, the better to meet
the local homeowner association objections or the wife's moods, and
beyond that it's a reel antenna that comes with some portables, but
they have black wire you can see and this doesn't.

--
Ron Hardin


On the internet, nobody knows you're a jerk.

Grove's Flex-tenna
 

For One and All,

The Grove {Hidden] Flex-Tenna has arrived
along with the Grove SW Pocket-Tenna for
Wideband Handheld Receivers.

http://www.grove-ent.com/shortwaveantennas.html

report to follow - iane ~ RHF

The Grove "Flex-Tenna" HVU Shortwave Listening (SWL) Antenna
 

Telamon - Your discription requires some thinking ~ RHF
19 Feet Coax & 5 Feet Wire
===================|
o------------------------------------|-----
===================|

Some how i think it comes out
19 Feet & 5 Feet
-------------------|-----
o

'o' = Feed Point

The Grove "Flex-Tenna" HVU Shortwave Listening (SWL) Antenna
 

In article .com,
"RHF" wrote:

Telamon wrote:
In article .com,
"RHF" wrote:


Telamon wrote:
In article . com,
"RHF" wrote:

JHR,

The Grove "Flex-Tenna" HVU Shortwave Listening (SWL) Antenna
http://groups.yahoo.com/group/Shortw...a/message/9886

Yes having the two Wires Parallel and within an 1/8" of each
other should effectively have the signals cancel each other out.

- B U T - The Wires are not the same length and therefore
a-differential is created between the two signal levels in the
two Wires. Because In-Fact the Two Wires are of Different
Wave Lengths.

One must 'assume' that Grove did some Design Planning or
practical Trial-and-Error Testing to get the Length of the Two
Wires so that they would give good results across the HF,
VHF and UHF Bands.
* 24 Feet is a little short for a 1/4 WL for the 31 Metre Band.
* 19 Feet is a little short for a 1/4 WL for the 25 Metre Band.

For Shortwave {High Frequency Only} one might try building
the same type of "Flex-Tenna Antenna made from Speaker
Wire with Two Wires that are a little Longer and have a Greater
'difference' in the Wave Lengths :

Shortwave Upper-Middle Bands :
* 38 Feet (a little short) for a 1/4 WL for the 49 Metre Band.
* 24 Feet (a little short) for a 1/4 WL for the 31 Metre Band.
= Delta of 14 Feet

Shortwave Lower - Middle Bands :
* 47 Feet (a little short) for a 1/4 WL for the 60 Metre Band.
* 31 Feet (a little short) for a 1/4 WL for the 41 Metre Band.
= Delta of 16 Feet

NOTE - The Flex-Tenna Antenna design lends itself to Speaker Wire;
Twin-Lead and Ladder-Line "Parallel" Wire type wire-structures.
Coax Cable for this Design of Antenna would not work IMHO.
The Outer-Shield of the Coax Cable would effectively Shield the
Section of the Inner Conductor of the Coax Cable and thus only
result in the Shield and Delta-Tip functioning as the 'differential'
Wire Antenna Elements.

FWIW - Most of the Coax Cable 'Liner' Antenna Designs are
basically End-Fed Dipoles beginning with a 1/4 WL of Coax
Shield with an ending with 1/4 WL of Exposed Inner Conductor.

The Grove "Flex-Tenna" HVU Shortwave Listening (SWL) Antenna
http://groups.yahoo.com/group/Shortw...a/message/9818

You could make a similar antenna out of coax but it would be more bulky
than the Grove version.

You can make loop antennas with coax that are balanced antennas. The
loops made of coax can be made sensitive to the E and M fields or just
the M field.

You could use the speaker wire to make a loop antenna that was sensitive
to the E and M fields.

Telamon,

Maybe someone could do some modeling of these two
types of Wire Antenna

First a piece of Speaker Wire with one Wire 24 Feet long
and the other Wire 19 Feet long using an "F" Connector
at the common Feed-Point-End.

Second a piece of Coax Cable with the Outer Shield
Terminated at 19 Feet and the Inner Conductor with
the Insulation still around it continuing for another
Five Feet for a Total Length of 24 Feet - again using
an "F" Connector at the common Feed-Point-End.

Some How I Do Not Think That They Are The Same Antenna.

but i could be wrong -and- you could be right - iane ~ RHF

Yeah, that would not.

I was think more along the lines of:

Starting from the radio the coax center conductor goes to the antenna
jack tip and the shield is not connected to anything. This coax is 19
feet long. At the coax far end the center conductor and shield are
connected together and a single insulated wire continues another five
feet starting at the center/shield junction.


Telamon - Your discription requires some thinking ~ RHF
19 Feet Coax & 5 Feet Wire
===================|
o------------------------------------|-----
===================|

Some how i think it comes out
19 Feet & 5 Feet
-------------------|-----
o

The shield is a 19 foot element and the 5 foot single insulated wire is
a continuation of it where the connection to this element is offset from
the end by 5 feet.

--
Telamon
Ventura, California

Grove Shortwave (SW) Pocket-Tenna
 

GW,

The Grove Shortwave (SW) Pocket-Tenna Antenna was
http://www.grove-ent.com/pocket-tenna.html
mainly designed by Grove for Hand Held Scanners or
"All Band" {HF-VHF-UHF} Hand Held Radios which
simply had a small short Flexible Whip {Rubber Ducky}
Antenna often connected to them using a BNC Connector.
http://groups.yahoo.com/group/Shortw...a/message/9935

First the BNC Connector - Designed for Hand Held Scanners and
Radios that often use them as an Antenna Connector and Input.

Second the Length {Size} - Most of these Hand Held Scanners
and Radios will OverLoad when a Larger Long Wire Antenna :
Say a Dipole 'cut' for the 31 Meter Band is used with them
rendering them useless.
- - - 31 Meter Dipole Antenna 49 Feet Tip-to-Tip.
I would suspect that Grove did a few Trial-and-Error 'design'
{Prototype} Antennas and found that about Twenty Feet was all
that most of these Hand Held Scanners and Radios could handle
before 'Size' {Length} caused a problem with "OverLoading"
the Radio's RF Front-End.
Note - This is about the same length as the 23 Foot Portable
Reel {Roll-Up} Shortwave Antennas that come with, or can be
purchased for most 'portable' AM / FM Shortwave Radios.
Again many of these 'portable' AM / FM Shortwave Radios will
"OverLoad" when a Larger Long Size Antenna is used with them.

Third - What to call {Label} this Antenna :
# 1 - It is End-Fed. {End-Fed}
# 2 - It is made from a single piece of Coax Cable {Liner}
and designed to have Two Equal Sections made-up of the Coax
Shield and Exposed Inner Conductor. {Balanced Mono-Pole}
# 3 - Not Really designed to be Resonant at any Shortwave
(HF) Band and used Across the Shortwave Bands. {All-Band}
What's-In-A-Name : End-Fed Liner Mono-Pole All-Band Antenna ?

TESTING - Again in a Side-by-Side trail it was my observation
using the 20 Foot Grove Shortwave (SW) Pocket-Tenna -vice-
23 Foot Portable Reel {Roll-Up} Shortwave Antenna with a
Grundig Satellit 800 Millennium Radio that the Grove had
as good a signal with less noise then the Roll-Up.
* Roll-Up connected via the Red HI-Z Terminal No-Ground.
* Grove connected via the SO-239 LO-Z Jack No-Ground.

THE QUESTIONS :
? Is the Grove a Great Shortwave Antenna ? -NO-
? For It's Intended Use - Does the Grove Antenna Work ? -YES-
? Is the Grove Worth $20 ? -YES and NO-
-Yes- Price about Right for those who simply want to Buy It to Use.
-No- Easy to Do-It-Yourself : If you have the Skills and Knowledge
plus the Tools and Materials to build it.

AGAIN THE [MY] BOTTOM LINE :
The Grove Shortwave (SW) Pocket-Tenna
http://www.grove-ent.com/pocket-tenna.html
Simple enough to build-it-yourself to play around with
and low cost enough to simply buy-it-and-try-it.

- - - In ,
http://groups.yahoo.com/group/Shortw...a/message/9931
- - - "Greg W:-)" onegammyleg@... wrote:


iane ~ RHF