ezz > fritid.* > fritid.hamradio

 #1  
01.06.2007, 17:27
Preben Larsen
Hej
Er der nogen som har prøvet at lave det der SDR radio som UY1LM beskriver
på sin hjemmeside?

[..]

Det er jo et ret simpelt setup i hardware...
Ligner noget man selv kunne smede sammen ;-)
vy 73 de oz1fhu Preben
 #2  
02.06.2007, 01:58
F.Syndergaard
Hej.
Jeg har været inde og se på det
og kan ikke finde noget diagram?
Hvad går det egentlig ud på?
 #3  
02.06.2007, 05:09
Leo Jørgensen
Du skal lige klikke over på Homebrew

[..]

og scrolle lidt ned, så kommer du til HF SDR RECEIVER CW-SSB-DRM YU1LM.pdf
[..]

og transmitter
[..]

og så et eller andet mere.
[..]

Jeg kender intet til det.

Hygsom
OZ9AEM
Leo
 #4  
02.06.2007, 11:09
Glenn Møller-Holst
F.Syndergaard wrote:
> Hej.
> Jeg har været inde og se på det
> og kan ikke finde noget diagram?
> Hvad går det egentlig ud på?


En SDR (Software-Defined Radio) går ud på at du nedblander kanalen og
demodulerer ved at:
*digitalisere (AD-konverter) ved en meget lav mellemfrekvens
*Demodulere i software

Dette kan gøres billigt ved at sende den lave mellemfrekvens ind i et
kvalitets computerlydkort og så foretage demodulationen i PCen.

-

Som man ved har en lav mellemfrekvens det problem at spejlfrekvens
modtages ligesågodt uden et urealiserbart HF-filter.

Dette løses ved at lave kompleks nedblanding. Resultat er nu to lave
mellemfrekvenskanaler med en indbyrdes faseforskel på ca. 90 grader
(ideelt 90 grader). Men man til en vis grad kompensere for fasefejl i
software.

Den komplekse nedblanding er 2 separate nedblandinger med hhv. "0
grader" signal og "90 grader" signal.

-

I demodulationsprocessen "samles" de to kanaler I og Q på passende
digital vis, så det ønskede signal bibeholdes og spejlfrekvensen dæmpes
meget.

Ved hjælp af software kan man lave alle demodulationer: SSB, USB, LSB,
FM, AM, CW.

Også OFDM, QAM...

Desuden kan man lave utroligt avancerede filtre:
*Variabel mellemfrekvens
*Exceptionelle LF-filtre (dykfilter...)
*NB - Noise Blanker
....

Hente meget svage repeterende signaler eller stationære frem
(EME-signaler...)

Stereo-dekodere, RDS-dekodere, Dolby dekodere...

En spektrumanalyser som dækker det som modtageren dækker.

-

I dag kan man lydkort med 24 bits opløsning og det svarer til et
dynamikområde på ca. 20*log(2^24) ca.= 144dB.

Dette betyder at man ikke behøver forvrængende HF-forstærkere eller
MF-forstærkere.

-

Kig f.eks. i de eksterne henvisninger her:
[..]

Eller kig her:
[..]

/Glenn
 #5  
02.06.2007, 11:20
Max
Hej Preben

> Det er jo et ret simpelt setup i hardware...
> Ligner noget man selv kunne smede sammen ;-)


Hvis du virkelig vil prøve at lege med det simple
og det billige, ja så kan du for 60 kr. komme
igang med en SDR, f.eks. en modtager til 40 m.

[..]
 #6  
02.06.2007, 11:23
Glenn Møller-Holst
F.Syndergaard wrote:
> Hej.
> Jeg har været inde og se på det
> og kan ikke finde noget diagram?
> Hvad går det egentlig ud på?


Kig også på:

[..]

[..]
Dioderne kan som gjort i YU1LM mikseren gøres med digitale kontakter;
f.eks. 74HC4066, 74HC4053...

IQ-kanalerne laves noget i denne stil:
[..]

[..]
Citat: "...The component that is in phase with the original carrier is
referred to as the in-phase component. The other component, which is
always 90° (\begin{matrix} \frac{\pi}{2} \end{matrix} radians) out of
phase, is referred to as the quadrature component..."

-

Kig evt. også på:
[..]

/Glenn
 #7  
02.06.2007, 11:28
Glenn Møller-Holst
F.Syndergaard wrote:
> Hej.
> Jeg har været inde og se på det
> og kan ikke finde noget diagram?
> Hvad går det egentlig ud på?


IQ-signalbehandling er faktisk en gammel metode som også anvendes ved
analog (og digital) SSB-(de)modulation:

[..]
Citat: "...
To generate an SSB signal with this method, two versions of the original
signal are generated which are mutually 90° out of phase. Each one of
these signals is then mixed with carrier waves that are also 90° out of
phase with each other. By either adding or subtracting the resulting
signals, a lower or upper sideband signal results.
...."

Det er vistnok denne metode YU1LM anvender:

[..]
Citat: "...
In Weaver's method, the band of interest is first translated to be
centered at zero, conceptually by modulating a complex exponential
exp(j?t) with frequency in the middle of the voiceband, but implemented
by a quadrature pair of sine and cosine modulators at that frequency
(e.g. 2 kHz). This complex signal or pair of real signals is then
lowpass filtered to remove the undesired sideband that is not centered
at zero. Then, the single-sideband complex signal centered at zero is
upconverted to a real signal, by another pair of quadrature mixers, to
the desired center frequency.
...."

/Glenn
 #8  
02.06.2007, 11:51
Glenn Møller-Holst
F.Syndergaard wrote:
> Hej.
> Jeg har været inde og se på det
> og kan ikke finde noget diagram?
> Hvad går det egentlig ud på?


Disse 90° filtre "laver" eller anvender analoge IQ-kanaler:

90° Hybrid 3dB
Directional Couplers
stik N H9223
stik SMA H9123
stik SMA H914
[..]

3 dB 90 Degree Hybrid Couplers
[..]

rat-race hybrids
[..]

Rat-race couplers
[..]

April 27, 1995 Allpass network shifts signals 90°. Gary Sellani,
Maxim Integrated Products, Sunnyvale, CA.
[..]

/Glenn
 #9  
02.06.2007, 12:05
Glenn Møller-Holst
F.Syndergaard wrote:
> Hej.
> Jeg har været inde og se på det
> og kan ikke finde noget diagram?
> Hvad går det egentlig ud på?


Artikler om:

ZERO-IF AND NEAR-ZERO-IF QUADRATURE RECEIVERS FOR SDR:
[..]
Citat: "...
Zero Intermediate Frequency (ZIF) and Near Zero
Intermediate frequency (NZIF) quadrature receivers are
more sensitive to circuitry mismatch, which causes I-Q
imbalance that may be frequency dependent over the
signal bandwidth.
...."

Mar 1, 2003, A Low-noise, High-performance Zero IF Quadrature
Detector/Preamplifier:
[..]

MAX2023
High-Dynamic-Range, Direct Up-/Downconversion 1500MHz to 2300MHz
Quadrature Mod/Demod.
Highest Linearity, Lowest Noise 1.5GHz to 2.3GHz ZIF
Modulator/Demodulator Enables Zero-IF Direct-Conversion Architectures
for DCS/PCS EDGE BTS Transmitters:
[..]

-

Flere SDR:

*SDR-1000*
A Software-Defined Radio for the Masses, Part 1:
[..]

Software Defined Radios. (anvender PowerSDR)
The radio that just keeps getting better!:
[..]
Citat: "...
FlexRadio Systems delivers the first truly open source Software Defined
Radio transceiver for Amateur Radio use. Receive Only versions are also
available for non Amateur Radio applications. Read the SDR Articles
and the SDR-1000 Product Information.
....
New! Integrated Automatic Antenna Tuning Unit now shipping.
...."

Software Defined Radio Articles by AC5OG:
[..]

A Software Defined Radio for the Masses, Part 4; QEX, Mar/Apr 2003.
The series concludes with a description of a DC-65MHz transceiver (the
SDR-1000) that will allow open software experimentation with
software-defined radios:
[..]

-

Lidt supplement:

Linux Hamradio Application and Utilities Homepage: New/Updated software:
[..]

f.eks.:

This software can demodulate DRM, AM, FM, SSB, CW from 12 kHz IF signal:
[..]

HDSSTV (nu RDFT):
The transmit side programs produce a wav file corresponding to the
binary file to be transferred. This wav file is then played by a sound
card, which produces the audio signal that is transmitted. The receive
side program converts a recorded wav file back into the original binary
file, if there were fewer errors than provided for by the error
correction codes:
[..]
Citat: "...In order to reflect what the software actually does, the name
"HDSSTV" has been changed to "RDFT". RDFT stands for Redundant Digital
File Transfer..."

A Brief Discussion of Some Software DSP Solutions I've tried:
[..]
Citat: "...
DSP is an acronym for "Digital Signal Processing". Anytime an analog
signal is converted to digital form and processed in some way, that is
DSP. The use of DSP techniques in amateur radio is exploding, both in
terms of its use in commercial transceivers and receivers, and in terms
of homebrew hardware and software construction projects available to and
undertaken by hams
....
I have found that Linrad does an absolutely superb job of allowing me to
hear the desired weak signal hidden in the midst of the all the noise
and clutter present at my QTH. It does this better than any other
receiving system I have ever tried.
....
[PS: Nu kan man også få musearm af at være radioamatør...:]
By clicking with the mouse cursor at any point on the waterfall
....
IT IS POINT AND CLICK RECEIVING!!!
....
If you want a different filter bandwidth or shape factor, you just take
the mouse over to the baseband display, and drag the filter curve wider
or narrower, and the filter adjusts graphically. THIS REALLY WORKS!!
...."

-

Linrad home page. (Part of SM 5 BSZ home page) (June 19 2005):
[..]

-

The T03DSP High Performance Transceiver with DSP IF processing:
[..]
Citat: "...
This WEB site is dedicated to the design of the HF transceiver with DSP
IF processing. This design is the result of the more than 2 years
experimenting, writing software and designing hardware.
....
The DSP is operating at 120 MHz...600 MOPS
...."

-

DSP-3 er udsolgt, men der arbejdes angiveligt på DSP-4:
[..]

-

RX-350 HF DSP RECEIVER (der findes en bedre udgave idag med DRM (Digital
Radio Mondiale) MF-udgang):
[..]
"...
The built-in 34 bandwidth filters from 300 Hz to 8 kHz are instantly
selectable by turning a knob. All filters are independent of mode -
use any available filter in any receive mode.
....
Momentary 'SWEEP' function shows band activity in 8 selectable
coverage rates. Find the signals without even being on frequency!
Simply tune to a desired frequency, select one of 8 SWEEP ranges, and
press the SWEEP button. Signals will be shown on the bar graph on
opposite sides of the starting frequency. A cursor will appear and
allow you to tune RX-350 to any signal visible on the screen. Easy!
....
RX-350 HF DSP Receiver $1199.00
....
SPECTRUM SWEEP DISPLAY 8 widths from 240 Hz to 2.4 MHz, with tuning
cursor and selectable Autosweep function.
...."

-

[..]

Til 2-meter båndet - og man kan lave EME (Earth-Moon-Earth) med den:

DSP-10 Project.
The DSP-10 is an amateur-radio, software-defined 2-meter transceiver
that can be built at home. It operates on SSB, FM and CW modes. Features
are tailored to operation with weak signals on VHF, UHF and Microwave
frequencies:
[..]

-

[..]
"...All schematics and design files are publicly available under a GNU
license..."

eller:

[..]

We're creating an open source Software Defined Radio. We're designing
the s/w and h/w to enable experimentation with the latest digital
wireless protocols:
[..]
[..]

-

[..]
[..]

-

Designing Filters for Software-Defined Radio
[..]

-

Her er en fiks og færdig DSP baseret HF-transceiver:

Ten-Tec is pleased to announce the successor to the original ORION
transceiver: ORION II:
[..]

Pris - sølle 3995$...av. Og så kan man ikke engang se SSTV, fjernsyn
eller Doom II på farveskærmen. Det er simpelthen anakronistisk at de har
sat et antikt drejespoleinstrument på forsiden hvor farveskærmen også er...

Opgradering? = ny firmware!

/Glenn
 #10  
02.06.2007, 12:15
Glenn Møller-Holst
F.Syndergaard wrote:
> Hej.
> Jeg har været inde og se på det
> og kan ikke finde noget diagram?
> Hvad går det egentlig ud på?


flex-radio.com nyheder. PS: Jeg har (endnu) ingen aktier i dette firma -
og har ikke lavet en sammenligning med andre SDR transceivere. PS:
kender ikke prisen for de forskellige modeller:

[..]
Citat: "...
Additionally, all A/D conversions are performed internally in the
FLEX-5000 so a sound card is not required. There are two additional
versions of the FLEX-5000 (models C and D) that provide higher levels of
integration.
....
The FLEX-5000C™ model has a built in Intel Core2 Duo processor and comes
with the Microsoft Windows XP operating system, wireless keyboard and
mouse. The FLEX-5000D™ includes everything above and adds a 9" LCD
display with touch screen, 300 Watt PA and a large tuning knob.
...."

FLEX-5000™ Transceiver Features at a Glance:
[..]
Citat: "...
The BEST Receiver Available. Period! [Når de nu selv skal skrive det]
....
Full Duplex Transmit and Receive Capabilities
...."

The FlexRadio FLEX-5000A™
High Performance Software Defined Radio at its Best!
[..]
Citat: "...
Top Performing Narrow-Spaced Two-Tone 3rd Order IMD Dynamic Range at 2
KHz - (Not 20 KHz Like Everyone Else Advertises). An Incredible 105 dB
on 14 MHz.
....
Industry Leading Narrow Spaced 3rd Order Intercept Point: +33 dBm at 2
KHz Tone Spacing.
....
No Sound Card Required!
No longer do you have to worry about interfacing a sound card to your
PC. The FLEX-5000 has integrated the A/D and D/A processing hardware
built inside the radio. A high quality 192 KHz 24-bit DACs with
exceptional performance numbers provides the spectral samples for the
DSP to process. The integrated converters also eliminate audio cabling
requirements between the transceiver and PC.
....
True Full Duplex Operation for Simultaneous Transmit and Receive
....
True Diversity Receiving with the Second Independent Receiver
....
By locking both receivers to the same frequency you can produce "stereo
diversity" which allows your brain to more easily sort the signal from
the noise.
....
Single 1394 FireWire Connection to your Computer
....
Transverter Ready - Full Duplex 28 MHz IF
The FLEX-5000's incredible receiver is perfect for weak signal VHF+ and
WSJT operation as a 28 MHz IF for interfacing to external transverters.
The FLEX-5000 will turn your VHF-UHF-microwave setup into the highest
performance station around. Full duplex operation opens the door for
satellite communications as well.
....
No External Calibration Equipment Required
...."

/Glenn
 #11  
02.06.2007, 12:31
Glenn Møller-Holst
Glenn Møller-Holst wrote:
> F.Syndergaard wrote:
>> Hej.
>> Jeg har været inde og se på det
>> og kan ikke finde noget diagram?
>> Hvad går det egentlig ud på? ....

> The FlexRadio FLEX-5000A™ ....


Blokdiagram:

FLEX-5000 Block Diagram
This PDF file is the block diagram of the FLEX-5000 full duplex /triplex
architecture:
[..]

Fundet via:
[..]

-

FlexRadio Systems Product Comparison:
[..]

FLEX-5000TM Transceiver Family FAQ:
[..]
Citat: "...
Q8. What happened to the SDR-X?

A. The SDR-X project is alive and well. The goal of the SDR-X project is
to build a supremely high performance multi-channel receiver. The target
market has shifted to commercial and government applications. The work
on the SDR-X resulted in the development of the FLEX-5000 family.
...."

PowerSDR Source Code 1.4.5 (zip):
[..]

/Glenn
 #12  
02.06.2007, 12:44
Glenn Møller-Holst
F.Syndergaard wrote:
> Hej.
> Jeg har været inde og se på det
> og kan ikke finde noget diagram?
> Hvad går det egentlig ud på?


SM 5 BSZ - I/Q mixer for direct conversion radio
(Sept 28 2001):
[..]
Citat: "...
The simple HCMOS mixer in fig 1. produces a second order spur at -50dB
when the level is adjusted for a standard low noise op-amp to degrade
the dynamic range by less than 3dB.
....
Fig 1. A quadrature nixer [mixer] using 74HC4052. The control inputs are
fed from a synchronous counter that divides a local oscillator by four.
As a result the switch loops through all four positions during a period
of 4 local oscillator cycles, see fig. 2. For each switch position only
one connection is made between the antenna and either output. This way
the make before break operation of the switch will not cause
shortcircuits across the coil as would be the case using 74HC4053 as in
an older design. The dynamic range of the 74HC4052 design is superior
to that of the 74HC4053 design.
...."

/Glenn
 #13  
02.06.2007, 12:47
Glenn Møller-Holst
F.Syndergaard wrote:
> Hej.
> Jeg har været inde og se på det
> og kan ikke finde noget diagram?
> Hvad går det egentlig ud på?


Lav denne søgning, hvis du vil vide mere om I-Q mixere:
[..]

/Glenn
 #14  
02.06.2007, 13:18
Glenn Møller-Holst
Max wrote:
> Hej Preben
>> Det er jo et ret simpelt setup i hardware...
>> Ligner noget man selv kunne smede sammen ;-)

> Hvis du virkelig vil prøve at lege med det simple
> og det billige, ja så kan du for 60 kr. komme
> igang med en SDR, f.eks. en modtager til 40 m.
> [..]


Kig også her - her er forklaring og diagram:

A small, low-cost "Software Defined Radio" receiver kit for 40-meters,
used with powerful software on the PC for multi-mode operation:
[..]

Diagram:
[..]

/Glenn
 #15  
02.06.2007, 13:58
Glenn Møller-Holst
Glenn Møller-Holst wrote:
> Max wrote:
> Kig også her - her er forklaring og diagram:
> used with powerful software on the PC for multi-mode operation:
> [..]
> Diagram:
> [..]
> /Glenn


SoftRock v.7.0:
[..]

/Glenn

Lignende emner