Chip64 v1.2 Direct Sequence Spread Spectrum  by IZ8BLY

 

The signal sounds like uninterrupted noise. Waterfall is a variable bandwidth.

 

Spread spectrum (SS) is a family of modulation techniques in which the transmitted signal occupies a

300 to 400Hz bandwidth, to transmit the bare information;  exploiting maximum available bandwidth, making

transmission “hidden”; to take advantage of the Spread Spectrum techniques even on the HF channels,

making the communication possible under conditions where traditional narrow band modes fail.

 

 

Hardware:

      A RIGblaster (1ea), Soundcard speaker cables: Radio Shack-42 2387 (3ea)

 

RIGblaster:

      Strap P1 to match your radio's Microphone. (i.e. RJ45 IC706 page 9). Set Audio Level

      Control full clockwise. Switch VOX/AUTO to AUTO, apply power. Cable RIGblaster to

      radio and computer, as shown in RIGblaster manual’s hookup diagram PC Speaker Out to Rigblaster In);

      Aux. In to Rigblaster Out). The RIGblaster interface will allow computer speakers to continue to operate

      for music etc.

 Note: Don't use low impedance un-amplified speakers.

 

Computer Downloads: http://xoomer.virgilio.it/aporcino/

 

Install to Chip64 folder:

 

Chip64 Setup:

   Click on IZ8BLY Chip64 Icon

   Click on FILE – PREFRENCES

       GENERAL: type in: Callsign – Name – QTH – Locator – E-mail –

                         Decoding options: change Squelch level from 5% to 40%

        PTT Port: Select COM1

        Waterfall: Select Logarithmic

        Tools: default SNDVOL32

        Click OK

   Click on MODE

       Select: Chip-64

       Select: Clocked decoder  (for Spread Spectrum mode,  activates Chip shape Window)

                 Note: some stations prefer to start a QSO  in Un Clocked decoder

   Click VIEW defaults

  

   Set Input volume/Set output volume:

      Recording Controls: Line In SELECT - Volume to 1/3 of the way up - Balance slider to the center

      Volume Controls: Volume:  Volume to 1/3 of the way up - Balance slider to the center

                     Wave Volume   to 1/3 of the way up - Balance slider to the center

                     Line In Volume to 2/3 of the way up - Balance slider to the center

                     Microphone Volume to 1/3 of the way up

                     PC Speaker Volume to 2/3 of the way up

 Note: Turn the computer speaker volume control knob most of the way, but not all of the way down.

   Click LOG window (activates QSO/Log windows)

   Right Click on Waterfall to set TX/RX Frequency to 1500 (in the middle of filters cutoffs)

   

Recommended frequencies:

       3.584   3.582.75  

7.090   7.077

10.134  10.137  10.140  10.187 

14.077  14.079  14.100  14.107.5  14.108.5  14.109.5  14.110

18.100  18.103

 

  Radio setup:

     Set all IF Filters to OFF (or as wide as possible)

     Set Audio RF to MAX

     Set VFO to: 7.090 

     Set Transmitter output power to ¼  manufacturer’s rated RF power output, 30 watts or

      less is a good operating setup to provide linear performance.

     Set Mode to USB (convention is USB for all Bands)

     Set Processor to OFF and SWR ON

     Adjust Tuner for 1:1

     Set ALC to ON and SWR OFF

     Speak into the Mic. Adjusting Mic gain so that ALC doesn’t occur above the ALC Zone

     Indicator.

     Adjust Tuner for 1:1

     ALC can remain (on) to control drive limit.

 

     Click on Chip64 CQ button (transmission starts).

      adjust RIGblaster Audio Level Control, stopping as transmitter output power reaches MAX

      (ie. 30 watts) keep an eye on your ALC so that ALC does not occur; run with NO ALC

      indicating occurring; any ALC indicating, results in your TX Signal being distorted,

      and causing harmonics.

     Stop TX (F 12)

 

 Note: The RIGblaster Audio Level Control is the most precise way to adjust the

        Soundcard output voltage into the radio. The Microsoft Volume controls were

        designed to vary the voltage, through a range of reasonable outputs for Speakers;

        They were not designed to be adjusted so precisely as to be reliable set to

        5 millivolts.

 

 

To Operate Chip64:

      Transmit:  (prepare to TX)

       Click  Ctrl + C  (Clears Transmit buffer)

 

      Transmit from Transmit window:

        Click a MACRO ie. BTU and follow with your message and end with F12 to end transmission and return to Receive mode.

 

      Transmit: (this option allows you to type, whole receiving text from the other Station)

        To type ahead:

              type: * followed by your message – To TX press Ctrl + T

        To End TX:  press F 12

 

       Transmit:

        To TX a File: press TRANSMIT – Select Send File – Select File – Click OPEN

                  File is transmitted (waterfall stops) (Buffer will count down to Empty)

        To End TX: press F 12

 

 

MUF Charts:  http://www.arrl.org/qst/propcharts/

DX Spots:        http://hamcall.net/dxspots 

DX Summit:    http://oh2aq.kolumbus.com/dxs/

DX Spot Cluster http://data.w6fk.com

DX-Telnet http://www.golist.net

Reflector:       http://groups.yahoo.com/group/chip64/

 

DX Summit: http://oh2aq.kolumbus.com/dxs/ 

   Searches:

    Click Spot Database Search

     Search string: type: Chip-64

     Click Any Column

     Click Search

   

   DX-Spots:

     Click Frequency   or

     Click Custom Spots – Digital

 

   Send your own Announcement:

     Click Send your own

                      Your Callsign (type): AA3EU 

                      DX Call (type): AA3EU

                      Freq. (type): 3583.5

                      Info. (type): Chip-64 unclock,  up 1500Hz  CQ CQ

                      Click Submit

 

Spread spectrum (SS) is a family of modulation techniques in which the transmitted signal occupies a

300 to 400Hz bandwidth, greatly wider than normally required to transmit the bare information. The

are several reasons for doing this, ranging from exploiting maximum available bandwidth to making

transmissionhidden”.Among the different possible implementations of SS, Chip64 uses the so

called Direct Sequence Spread Spectrum (DSSS). In a DSSS transmission, the low speed signal containing

the data bits to be transmitted is mixed (multiplied) with a greatly higher speed signal called code. The

result of this mixing operation, named spreading, is a high-speed bit stream which is then transmitted as

a normal D-BPSK. Indeed, a DSSS signal looks like nothing else than a wideband BPSK.

Considering the fact that data can be get back by the inverse operation, the mix of the data with the code

has the purpose of transferring on the data stream some of the properties of the code. These properties

are then exploited in the receive process allowing a different and advantageous decoding system than

traditional BPSK.

The code used in the spreading process is a sequence of bits which has the properties of randomness,

autocorrelation and cross-correlation.

 

The design of this new digital mode served to introduce the Spread Spectrum technology among radio

amateurs. Its purpose was to prove that it’s possible to take advantage of the Spread Spectrum techniques

 even on the HF channels, making the communication possible under conditions where traditional

narrow band modes fail.

 

 

References:

    http://arrl.org/FandES/field/regulations/techchar/chip64.htm

 

 

Test equipment software:

    Audio Signal Analyser: SpectrumLab v204b29 (speclab24b29.zip)  www.xs4all.nl/~nl9222/software.htm 

    Oscilloscope, Dual-trace: WinScope 2.51 ( osc251.zip)  www.electronicsaustralia.com.au/cgi-bin/downloads.pl?area=5

    Spectrogram v5.0.8  (gram517.zip)  http://neasmn.org/ben/software/software.htm 

    Spectrogram v4.2.6  (gram426.zip)

    Analyzer 2000 v5.04  (Pay for)      www.dxzone.com 

 

      Spectrogram setup:

      Click on GRAM4264 Icon (spectrogram window is activated)

      Click FILE

      Click F4 Scan Input (set Scan Input parameters)

      Click OK (view signals on frequency) set VFO that receive signal to start at 400Hz

      To Exit: Click STOP - FILE - EXIT

 

Joe Mettle sends: