DL8YCA - WSPR

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dl8yca[AT]darc.de      updated 2018-10-25

  

 

October 2018: Yet another "Stand-Alone" WSPR Mini SSB-Transceiver for the 17m Band , Igel-Mini-PC, Debian 9, WSJT-X 1.9.1 and another magnetic loop antenna in the utility room.

 

December 2017: Linux Mini-PC Setup for 24/7 WSPR RX/TX Operation

 

November 2016: The next "Stand-Alone" WSPR Mini SSB-Transceiver for the 80m Band, 1 W, in part retro 1980s design due to a lot of available parts, One-Weekend-SMD-Project, Igel-Mini-PC, Ubuntu 14.04, WSPR 4 and indoor stealth magnetic loop antenna

 

     
October 2016: "Stand-Alone"
WSPR Mini SSB-Transceiver for the 40m Band , 1 W, in part retro 1980s design with 2 PLLs due to a lot of available parts, Igel-Mini-PC, Ubuntu 14.04, WSPR 4 and another magnetic loop antenna in the utility room.

 

  
June 2016: "Stand-Alone" WSPR Mini SSB-Transceiver for the 30m Band, 0.5 W, Retro 1980s design due to a lot of available parts, Igel-Mini-PC, Ubuntu 14.04, WSPR 4 and a magnetic loop antenna in the utility room.

November 2015: 136/475-kHz Linear Amplifier Vers. 1.1 and 136/475 kHz Class D Amplifier for JT65, WSPR etc.. Signal source for both bands is the TX Preamp Output of the above-mentioned ICOM IC735 mod. or a MF/LF transverter integrated in a Lincoln 1 CB transceiver.

September 2015: The MF antenna situation could be better and so it is time to try another indoor magnetic loop with coaxial cable laid in two adjacent rooms (Indoor 136/475kHz Magloop Vers. 2

June 2015: Trying to use an old FT757GX for WSPR. Problems with a not acceptable frequency drift after warm-up dependent on temperature of the reference Xtal (local unit) affected by the changing air flow in the case (Cooling fan on/off effects a frequency change up to 50 Hz in 2 min). Slow drift up to 200 Hz.
A reference Xtal temperature and fan control reduced the wspr drift to 1 - (-1) and the slow drift after warm-up to max. 10 Hz, when WSPR was set to 20% TXing @ ~ 3 W. The sensor diode and the Collector of the BD136 are clipped to the electrically grounded Xtal case. An additional permanently slow (temperature related) speed of the fan ensures a minimal air flow in the TRX case avoiding the aprupt temperature change in the case when the fan starts with full speed.

December 2014: Back to QTH Bochum, JO31PL.

May 2014: An ICOM IC 735 for parts and not fully operational bought at another ebay auction, was repaired and then modified to work on the 630 m - Band. An easy and safe modification of the IC 735 is described by SQ5BPF. The result of the modification is a rf output @ 472 MHz of 40 W (limited by the not modified ALC and the inductance of the PA output transformer) with a double pi filter between radio and antenna reducing the 2nd harmonic to >= -40dB.

 


DL8YCA's radio and computer shack 2013  

October 2013: Starting another quick-&-dirty weekend project I modified an old 11m/10m SSB-CB-transceiver (PA died) with a 10m-LF-transverter (QRP output 36-40 dBm @ 475 kHz). It works fine, the frequency drifts 30Hz/6 hours. Not particularty impressive, but sufficient for WSPR. From a CB-Amplifier bought at an Ebay auction I removed all the electronic components and 'designed' a new linear PA circuit with an CW output of 40 W, just the limit for the variable capacitors of my new single turn indoor magnetic loop.

July 2012: Multiturn 2.5 m x 2.0 m stealth tx/rx magnetic loop and a QRP linear amplifier/preamplifier for the new 475 kHz band.
Nov. 2012: The efficiency of this antenna @ 475 kHz is very low, but it is better than nothing. Although the environment of the antenna is very lossy (concrete floor and ceiling etc.), with 5 W TX output (~ 1 mW ERP!) the groundwave of my signal can be read up to 100 km and the skywave at least 1000 km.

January 2012: I have got an old, heavy (>30kg) but perdurable spectrum analyser HP 8555B/8553B and now I have the test equipment again I need for RF design and repair. In the next weeks I will finish a 28/144 MHz - transverter for WSPR and other digital modes with the FLEX-1500 on VHF.

 

Flex-1500 SDR-QRP-Transceiver, Medion Akoya E1312 Netbook, homebrew matchbox, preselector and preamplifier, Win XP, PowerSDR 2.0, WSPR 2.0, VAC, ComOCom.It is no problem to work with the Flex-1500 and his software and simultaneously with a CAT-controlled Yaesu Ft-817 ND, a 2nd instance of WSPR 2 and Spectrum Lab on the E1312 Netbook


November 2010: Kenwood TS140S, MFJ 1040C preselector and preamplifier, homebrew matchbox,
Medion Akoya 1210 Netbook (Intel Atom 1.6 GHz), Debian 6 Linux, WSPR 2.11 and fldigi. (Linux since 05/2011).