How the hell can I do a VHF antenna with these elements?

[autorun]

I've got a Terratec with e4000 tuner. I want to make an antenna but I don't know ANYTHING. The dongle has PAL input.

These are my materials: coaxial cable, and the poor antenna included.

Is it possible to extend the antenna included with coaxil cable? Because I don't have PAL connectors and I wouldn't like to cut the one in the included antenna.

[jdow]

1) Extend the USB cable - one 5M extension cord works. A 5M active extension
plus one 5M passive extension is currently working for me. (But I feel that
is seriously pushing things.) Get the antenna away from the computer (and TV)
noise sources.

2) For FM broadcast 2.5' is a good antenna length. But use the magmount on a
large metal cookie pan as a half-assed counterpoise. It'll work better. Old
clip-leads break with time and flexures. Take a broken one and clip it to
the whip. Cut it to make the length you want. VERY roughly speaking the
length you want is about 1/(4 * Fghz) for a 1/4 wave antenna. That means the
little spike is not bad at all at its design frequency for DVB-T broadcasts.
Of course better antennas are available and are good.

3) If you can avoid long feedlines, however you kludge it, do so. At UHF coax
feed lines are beyond horrible for any significant distance unless you use a
good antenna amplifier at the antenna.

4) E-Bay is your friend. PAL to BNC adapters are easy to obtain. So are
pig-tail adapters, which are perhaps better.

That's the 101 level course maxims.

{^_^} Joanne

On 2014/02/22 10:04, autorun wrote:
> I've got a Terratec with e4000 tuner. I want to make an antenna but I don't know
> ANYTHING. The dongle has PAL input.
>
> These are my materials: coaxial cable, and the poor antenna included.
>

> <https://lh4.googleusercontent.com/-ngneog098d0/UwjmcIsD4RI/AAAAAAAAAOw/wi8qXaqXRg8/s1600/2014-02-22+14.44.16.jpg>
>
>
> <https://lh5.googleusercontent.com/-pq1baPuYVm8/Uwjmgp-a0FI/AAAAAAAAAO4/lZB5uLyJbY4/s1600/2014-02-22+14.44.57.jpg>
>
>
> <https://lh3.googleusercontent.com/-zvSSmRY0QDk/UwjmkP5WLII/AAAAAAAAAPA/ROmZvVpaTdI/s1600/2014-02-22+14.45.26.jpg>

>
>
> Is it possible to extend the antenna included with coaxil cable? Because I don't
> have PAL connectors and I wouldn't like to cut the one in the included antenna.
>

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[Larry Dighera]

On Sat, 22 Feb 2014 10:04:25 -0800 (PST), autorun <agus...@gmail.com> wrote:

>I want to make an antenna but I don't know ANYTHING

You could consider purchasing an antenna. Here's one that's resonant from 100
Hz to 1000 MHz:
<http://www.rohde-schwarz.us/en/products/radiomonitoring/antennas/AM524-|-Key_Facts-|-4-|-2028.html>
:-)

[Dan KB6NU]

All of Joanne's suggestions are good. I'd definitely suggest buying your own connectors and maybe a length of coax cable. 

I was mainly interested in using my dongle for receiving FM broadcasts and monitoring the VHF/UHF repeaters in my area. I cut off the whip antenna (it was truly useless for me), and then connected end of the coax to an FM broadcast dipole that I had. Worked great! 

You can make your own dipole. All you have to do is to cut two lengths of wire, using the formula l = 234/f(MHz), where l is the length in feet. Connect one of the pieces of wire to the center conductor of the coax and the other to the shield, and you're in business.

73!

Dan KB6NU
----------------------------------------------------------
CW Geek, Ham Radio Instructor
Station Manager, WA2HOM at the Hands-On Museum (www.wa2hom.org)
Read my ham radio blog at http://www.kb6nu.com

[autorun]

Thanks!

In fact, I'm really interested. I said that airport/police thing as an example of my problem.
I was watching this video from the National Film Board of Canada, which reminds me math and physics I've seen at university. I'm trying to process information.

Well, I'll try tweaking the RF Gain and I post here.

[autorun]

Dan KB6NU and Larry thanks.
I read about the dipole antena, and it seems easy as you say, but I can't visualize it until I see it, really. Thanks anyaway. I'll keep reading.

It worked a lot rising to 16dB. And also the magmount on the metal cookie pan!
I thought it was a lot of decibels.

[jdow]

There is such a thing as a sense of proportion, you know.

{^_^}

[Bill Allardyce]

http://www.testequipmentconnection.com/products/12091?gclid=CIyCtarr-7wCFUVo7AodpDEAOA

and you can buy it for $32,000 or

you could check this page for ideas

http://sdrformariners.blogspot.com/2013/10/beginner-antennas.html 

[Larry Dighera]

Someone once said, "There is such a thing as a sense of proportion." :=)

First and foremost, the ARRL book titled Basic Antennas by Joel R. Hallas
<www.amazon.com/gp/product/087259999X> is the best starting point for anyone
who whishes to understand the fundamentals of wireless antennas, however the
cost is 200% of the RTL dongle.

Second, the definitive antenna reference is Reflections by M. Walter Maxwell
<http://www.amazon.com/gp/offer-listing/0872592995> is a good follow-on for the
serious student of antennas.

However, an Internet search can turn up some very good material:

<http://pdf-world.net/download.php?id=382619>
Basic Antenna Theory
Ryszard Struzak

<http://www.arrl-ohio.org/SEC/nvis/basicantennas.pdf>
Understanding Antennas For The Non-Technical Ham
A Book By Jim Abercrombie, N4JA

<http://www.globalsecurity.org/military/library/policy/navy/nrtc/14092_ch2.pdf>
ANTENNA CHARACTERISTICS

<http://highered.mcgraw-hill.com/sites/dl/free/0072321032/62577/ch02_011_056.pdf>
Antenna Basics

<http://www.apparentlyapparel.com/uploads/5/3/5/6/5356442/_____practical_antenna_handbook_fourth_edition_carr.pdf>
Practical Antenna Handbook

<http://sgar91.files.wordpress.com/2011/09/wireless-communication-and-networks-2nd-edition-william-stallings.pdf>
WIRELESS COMMUNICATIONS AND NETWORKS

<http://www.alexandre-boyer.fr/alex/enseignement/cours_antennes_oct11_v4_5RT.pdf>
ANTENNES

Oh, and there's always the wide-band (?) fractical antenna. Here's an excerpt
of a post I made in the SDR Sharp group last October:

Few antennas are designed without compromises. :-) My hex-beam is an
example...

I've had remarkable success receiving UHF signals up to about 500MHz with
the little antenna shipped with the USB stick. And, very good performance
with tuned transmitting antennas on nine bands (with an upconverter).

Designing a compact antenna with the bandwidth to match the tuning range of
the RTL receiver, some 1.67 GHz, would necessarily be a challenge and a
compromise. But considering the performance provided by the supplied
antenna, I'd wager that performance might be adequate with the antenna I've
been considering.

However, I've seen reports of fractal antennas performing well.


<http://www.eevblog.com/forum/chat/inexpensice-software-defined-radio-and-evolved-fractal-antennas/>
<http://alglobus.net/NASAwork/papers/Space2006Antenna.pdf>

"Whereas the current practice of designing antennas by hand is severely
limited because it is both time and labor intensive and requires a
significant amount of domain knowledge, evolutionary algorithms can be used
to search the design space and automatically find novel antenna designs
that are more effective than would otherwise be developed. Here we present
automated antenna design and optimization methods based on evolutionary
algorithms. We have evolved efficient antennas for a variety of aerospace
applications and here we describe one proof-of-concept study and one
project that produced light antennas that flew on NASA's Space Technology 5
(ST5) mission."


<http://ieeexplore.ieee.org/xpl/articleDetails.jsp?arnumber=1227902>
"Fractal wideband antennas for software defined radio, UWB, and multiple
platform applications"


<https://groups.google.com/forum/#!topic/house4hack/1zMRQAuV6FI>
Over on the RTL-SDR Facebook Page, Boris Lukac has shared a link to an
Instructable by tigers58 for a omnidirectional fractal HDTV antenna. The
simple build covers 50-1100MHz making it perfect for general use with a
RTL-SDR and for grabbing some extra HDTV channels when not hooked up to
your dongle. The supplies needed to build the antenna may already be laying
around your home or workbe...


<http://defenseelectronicsmag.com/site-files/defenseelectronicsmag.com/files/archive/rfdesign.com/mag/508RFDSF1.pdf>

<http://www.rtlsdr.com/2013/07/fractal-antenna-for-use-with-rtl-sdr-or-your-hdtv/>

And yet another post:

I've been considering the purchase of one of these:

<http://www.ebay.com/itm/320832340973>
Double Discone High Performance antenna

A high gain discone type wideband receiving antenna, with a low SWR across
the VHF/UHF Bands. The antenna has approx. 2.8db gain over a conventional
single discone, and provides excellent matching into 50 ohms for transmit
or receive. Manufactured in England from high quality components designed
to last in all types of environments.

Double Discone
Frequency Coverage
Receive 25-1300 MHz
Transmit 130-175 Mhz
and 410-475 MHz
Power handling 200 watts
Length 1.70 m
Radials 16 x 82 cm
Radials 16 x 82 cm
Connection 'N' Type

The antenna provides gain and lower radiation angle than conventional
discones to increase your reception power.
--------------------------------------------

<http://www.ebay.com/itm/221149255705>
V-1300 Desktop Antenna

Frequency Coverage
Receive 25-1300 MHz
Length 0.95 m
Radials 4 x 14 cm
8 x 41 cm
Impedance 50 Ohms
Base 90 mm magnet
Complete with 4 meters of
cable and BNC connector.

Ideal for use at home or outside

The point is, there's a lot of antenna information available on the Internet
for those willing to search a little.

Edison had a sign bearing this inscription posted in each of his laboratories:

There is no expedient to which a man will not resort
to avoid the real labor of thinking.
-- Sir Joshua Reynolds

Best regards,
Larry

On Wed, 5 Mar 2014 08:45:34 -0800 (PST), Bill Allardyce
<william....@gmail.com> wrote:

>http://www.testequipmentconnection.com/products/12091?gclid=CIyCtarr-7wCFUVo7AodpDEAOA
>
>and you can buy it for $32,000 or
>
>you could check this page for ideas
>http://sdrformariners.blogspot.com/2013/10/beginner-antennas.html
>
>On Sunday, February 23, 2014 9:15:41 AM UTC-6, Larry wrote:
>>

>> On Sat, 22 Feb 2014 10:04:25 -0800 (PST), autorun <agus...@gmail.com<javascript:>>

[jdow]

For receive antennas a couple pieces of wire with coax out away from noise
sources is going to receive something useful at FM broadcast and aircraft
frequencies. As you go upwards you may want to shorten the coax as it has
appreciable loss at higher frequencies. For a receive only antenna a preamp
is good. Cutting it to roughly 1/4 wavelength per wire and stretching the
two wires out end to end with the coax in the center improves things somewhat.
Beyond that you get into fancy antennas.

A desktop antenna makes me shudder with disgust. That involves putting the
antenna in the midst of the highest RF noise levels in your house. That
is a pretty damn fool thing to do.

{^_^} Joanne

[Carol F. Milazzo]

Here are my plans for a wideband discone antenna that covers 100-1300 MHz for $15 https://picasaweb.google.com/114032640816757126398/Homebrew15DisconeAntenna#

It works well with RG-6/U 75 ohm cable.  Get the antenna outdoors in a clear spot and use the shortest length of coaxial cable possible.

To minimize loss I've also connected the RTL-SDR dongle directly onto the antenna and run a USB extension to the computer.

Carol

[Larry Dighera]

Dear Dr. Milazzo,

Many thanks for sharing your impressive antenna design. Its construction
simplicity and economy surely make it a candidate for the de facto standard for
RTL-SDR use.

I very much enjoyed reading your myriad web pages:
<https://plus.google.com/114032640816757126398/about>,
<http://www.qsl.net/kp4md/>, <http://www.qsl.net/kp4md/kp4mdnec2.htm>,
<http://www.youtube.com/user/kp4md>, ... And I was pleasantly surprised at
your historic involvement with the TIMEX/SINCLAIR ZX81, with which I have some
familiarity: <http://kj6yvt.com/speak&spell_Feb1983.PDF>.

Your accomplishments are quite impressive and interesting. This list is
fortunate to have some very accomplished female "radio-heads" among its
membership, not to mention the many males who also generously provide the
fruits of their talents, so that we dilettantes may enjoy the magic of wireless
phenomena.

Best regards,
Larry

PS: Have you seen this: <http://www.udoo.org/>?
The imbedded Arduino DUE provides means to support near real-time IRQ-based I/O
for a Linux system running on a four-core uP:

Freescale i.MX 6 ARM Cortex-A9 CPU Dual/Quad core 1GHz
Integrated graphics, each processor provides 3 separated accelerators for
2D, OpenGL® ES2.0 3D and OpenVG™
Atmel SAM3X8E ARM Cortex-M3 CPU (same as Arduino Due)
RAM DDR3 1GB
76 fully available GPIO
Arduino-compatible R3 1.0 pinout
HDMI and LVDS + Touch (I2C signals)
Ethernet RJ45 (10/100/1000 MBit)
WiFi Module
Mini USB and Mini USB OTG
USB type A (x2) and USB connector (requires a specific wire)
Analog Audio and Mic
SATA (Only Quad-Core version)
Camera connection
Micro SD (boot device)
Power Supply 12V and External Battery connector

On Sun, 16 Mar 2014 19:01:10 -0700 (PDT), "Carol F. Milazzo"
<kp...@cfmilazzo.com> wrote:

>Here are my plans for a wideband discone antenna that covers 100-1300 MHz
>for $15

>*https://picasaweb.google.com/114032640816757126398/Homebrew15DisconeAntenna#*<https://picasaweb.google.com/114032640816757126398/Homebrew15DisconeAntenna#>

>It works well with RG-6/U 75 ohm cable. Get the antenna outdoors in a
>clear spot and use the shortest length of coaxial cable possible.
>To minimize loss I've also connected the RTL-SDR dongle directly onto the
>antenna and run a USB extension to the computer.
>
>Carol
>

><https://lh3.googleusercontent.com/-otoCrZPX-t8/UTPur3hg7II/AAAAAAAAErQ/Pug1g-elzoo/s720/discone1.jpg>

>
>
>On Saturday, February 22, 2014 10:04:25 AM UTC-8, autorun wrote:
>>
>> I've got a Terratec with e4000 tuner. I want to make an antenna but I
>> don't know ANYTHING. The dongle has PAL input.
>>
>> These are my materials: coaxial cable, and the poor antenna included.
>>
>>

>> <https://lh4.googleusercontent.com/-ngneog098d0/UwjmcIsD4RI/AAAAAAAAAOw/wi8qXaqXRg8/s1600/2014-02-22+14.44.16.jpg>
>>
>>
>>
>> <https://lh5.googleusercontent.com/-pq1baPuYVm8/Uwjmgp-a0FI/AAAAAAAAAO4/lZB5uLyJbY4/s1600/2014-02-22+14.44.57.jpg>
>>
>>
>>
>> <https://lh3.googleusercontent.com/-zvSSmRY0QDk/UwjmkP5WLII/AAAAAAAAAPA/ROmZvVpaTdI/s1600/2014-02-22+14.45.26.jpg>
>>
>>