Poor ground beneficial for smooth vertically polarized WSPR-antenna patterns (Nov. version: improved notation, figures pending)Submitted by OH1ZAA on Fri, 2010/09/24 - 19:24
At OH3MHA we use for WSPR-communications presently a 4 x 3 m vertical (28/25/22/19mm Alu-tubing, totally 11.5 m in length) attached to a wooden fence support, with the fence's wires (cut for various lengths) functioning as the radials. SWR is excellent on 7 MHz. On the 10/14/18/21 MHz bands it can be forced to accept some RF-power with matching circuits. There is considerable loss in the long RG-58 cable. Finally it is the magnitude of the current in the vertical element that is forming the amplitude of the radiated field in cooperation with the properties of the surrounding soil.
The station is situated in an industrial area with poor ground (assuming a dielectric constant of ε = 5 and a conductivity of 5 mS/m). Pending future site improvements it was decided to run some simulations with a design frequency of 14.15 MHz using the free MMANA 188.8.131.52 simulator. To get rid of the radials, a J-pole structure seemed suitable, while the matching section is usable as a mechanical support to get the radiating part of the [vertical dipole] element up in the clear. Starting at 1 m elevation with the structure base the top of the structure arrives at 17.7 m height (guying ropes certainly needed, unlike with the first vertical).
The simulation was done for Ocean water (dielectric constant ε = 80 ; conductivity 4000 mS/m), Lake water (ε = 80 ; 1 mS/m), Good ground (ε =20 ; 20 mS/m), and Poor ground (ε = 5 ; 5 mS/m). Though the maximum intensity of the radiated far field does not change more than 1.5 dB between the cases, its dependence on the take-off angle is huge. Over Ocean water one is able to launch into a low angle of 5 degrees, but there is a -13 dB relative dip at 20 degrees take-off, and even a stronger wide maximum peaking at 44 degrees vertical elevation.
It's been quite an effort to get WSPR to run stably on an FBSD 8 system. The best course I have
found, after lots of false starts, has been to use the windows version inside a VirtualBoxOSE
emulation. This runs fine but I haven't had any luck getting the CAT (CI-V for Icom types)
interface to work. PTT is no problem.
Running WSPR natively, via the port in ports/comms, seems hopeless in the amd64 environment
that I prefer to use for general work. I have built an i386 machine, and on that platform
WSPR will run properly for up to two or three hours; but it generally bombs out with TK errors
if one waits patiently.
Would love to hear from anyone who's got some insight into this. Alternatavely, if there are
any stable Linux versions, would consider that an attractive option. Suggestions?
The following is a minimalistic design of a standalone MEPT beacon used for WSPR broadcasts. It is based on a Si570 programmable crystal oscillator (silabs.com) which is controlled by means of an AVR attiny45 microcontroller. The Si570 device is FSK modulated by the AVR via a sequence of I2C control commands that are sent to slightly change the frequency for every transmitted WSPR symbol, allowing multiband operation on frequencies like:
3.5926MHz, 5.2872MHz , 7.0386MHz, 10.1387MHz,
14.0956MHz, 18.1046MHz, 21.0946MHz, 24.9246MHz,
28.1246MHz, 50.293MHz, 144.488MHz.
The Si570 device outputs a power of about 10mW which is already sufficient for WSPR operation, a small BS170 based power amplifier can be added to increases the power up to 500mW.
The beacon can be based on the foundation of existing kits such as USB Synth, FA-SY1 and SoftRock Ensemble Receiver or Transceiver Kit. Note when downloading the si570wspr_r20100922.ppt file, it must be renamed to si570wspr_r20100922.zip in order to be able to view the contents.
Note that the hex. representation of fuse setting in the document are wrong, they should be: highbyte=0x5d and lowbyte=0xef
BeaconTNG does it's first transmits! - Check www.oe1ifm.at
Today I got to a point in software development, where I could TX my first WSPR sequences on 14 and 10MHz.
The framework is more or less ready, a lot of cosmetics left, but all building blocks work just fine.
The most impressive facts:
Frequency accuracy : < 0,02Hz
Time accuracy : < 10ms
Time and frequency base : Navsync CW-25TIM
Power consumption in sleep mode : < 10mW
Frequency range : 1MHz - 55MHz
Power Range : 10dBm - 40dBm
Number of filters : 8
Log file memory : 1MB
Processor : PIC 18F87J60
Interfaces : serial terminal, Ethernet (Telnet), 3x16LCD display
I/O ports : 8 opto isolated digital outputs (eg for antenna relays, power or temp management)
2 opto isolated digital inputs (eg external wake up or shut down)
10MHz GPDSO reference out
Because of an overwhelming level of interest, discussion among those testing WSPR 2.1 -- designed for stand-alone operation with the SoftRock RxTx Ensemble and similar SDR transceivers -- has been moved from a private email list to the WSPRnet "Questions and Answers" Forum. See the topic "WSPR 2.1, for I/Q SDRs".
You may still send bug reports to me directly.
-- 73, Joe, K1JT
As of the 15th September 2010, I'm waiting to recieve a kit for the new Softrock RXTX ensemble.
Idea being it will run 24/7 on 40/30/20 Mtrs totally seperate to my main station.
1 Watt output, think that will give a good indication as to which of the bands are open.
I am currently experimenting with a WSPR version that controls and operates radios like the SoftRock RxTx Ensemble.
With WSPR 2.1 you can check a box labeled "Enable I/Q mode" on the Advanced Setup screen. The program will then use 2-channel sampling at 48000 Hz for both input and output. Your SoftRock sends its I/Q baseband signal to the computer's soundcard input; the soundcard output, also in I/Q format, goes to the SoftRock's Tx audio port. T/R switching is accomplished over the USB port. You need no other software such as Rocky or PowerSDR, and there's no need for anything like Virtual Audio Cables. Setup is extremely simple.
Over the past several days I've been running an early version of WSPR 2.1, in Rx-only mode. Right now I'm running in Tx-only mode, Txing 33% of the time, on 30 meters. It seems to get out well. I'll probably finish the T/R switching code and be in full operation within a day or so.
Currently running 500mw through an FT-817 into a BigIR vertical. Station operating 15M 9/17/10. Heavy power line noise from 500kV line 300ft from station.
Joe, K1JT, officially published a beta version of WSJT9 (http://www.physics.princeton.edu/pulsar/K1JT/wsjt.html).
Unfortunately this version doesn't support WSPR (including the QSO Mode) any longer without any further notice.
Some apparently bad entries are showing up in the 600meter database from aa 'station' called DO3BOX at GS JO30ix.
Anyone know what is happening with these entries?
73 - Dick w7wkr wd2xsh/26
I just saw some weird log entrys in the database, which are listed for my call as listener with no frequency and with dates in the future.
I uploaded yesterday some log-data to the database. That log was from some wspr activity while I was not connected to the Internet and I wanted to make the heared stations public. It seems that something gone wrong during the import of the log.
I'm very sorry for that.
I've finished my full sdr transceiver, based on free HASDR.
Special thank's at: F6ECI, PE0SSB, DL2JTE, F8BOJ, and others OM's for their technical support.
Well what can I say,
Set up the program connected the rig as easy as that, have had decodes from as as far away as 6800 km just with 1 watt of power on 30mtrs.
Wow - I like this mode :) I am now wondering what I could use this for is it possible to id a station and then arrange a sked on one of the other weak signal modes like jt6m ?
I think I need to have a play and see what happens.
Propagation was very good last Tuesday morning.
I was able to hit Antarctica with about one milliwatt using my Thunderbird 5 mk 2 at 60 feet.
Timestamp Call MHz SNR Drift Grid Pwr Reporter RGrid km az
2010-08-31 14:06 WA7KGX 14.097121 -19 0 CN85no 0.001 VP8DMH FC52wk 13390 159
2010-08-31 14:08 WA7KGX 14.097122 -20 0 CN85no 0.001 VP8DMH FC52wk 13390 159
2010-08-31 14:16 WA7KGX 14.097140 -23 0 CN85no 0.001 VP8DMH FC52wk 13390 159
2010-08-31 14:18 WA7KGX 14.097140 -24 0 CN85no 0.001 VP8DMH FC52wk 13390 159
2010-08-31 15:02 WA7KGX 14.097007 -28 0 CN85no 0.001 VP8DMH FC52wk 13390 159
Other than this, I have not been able to get past the East Coast with 0 dbm.
I put up a delta loop for 30 meters. I am feeding the loop at its apex which is at 25 feet. TX power is set to 10 watts.
A 1/4 transformer for matching.
The loop appears to be doing well as I am being heard by:
I just set up a MEPT with WSPR, PowerSDR, a SoftRock RXTX Ensemble and a 40m delta-loop.
Power must be lower than 500mW but hard to measure for now.
I hope to turn the MEPT on during the following nights but I still have some details to sort out.
Finished my SDR Lite II last saturday for 30m. Last night I started VAC + Rocky + WSPR to see
if any good. And yes it works :-)
Slightly off frequency, but have no decent time marker available to adjust the single band setting
in Rocky. But hey it's good enough tot start with.
Antenna is a simple dipole, parallel fed with a Diamond W735. The W735 is now a 4-bander (80/40/30/20), just 2
meter above ground.
Sorry! My english is not so good if I want to write someone, then please in german! Thank you!
Sorry! Mein englisch ist leider nicht so gut, wenn mir jemand schreiben möchte, dann bitte in deutsch! Danke!
Tried WSPR for the first time today had so issues with the software but seems to be somewhat ok now. Saw a lot of stations on 20M and 1 on 30M will try to get on more to fully check it out.
While setting up for WSPR ops- the first time in a long time- I noticed a lot of "racket" (noise) just before and after the WSPR program transmits its audio tones.
Some further observation found that; regardless of the WSPR program, my FT-857D (s/n 4J31...) makes a great deal of audio noise in transmit mode. The noise is obvious, when all audio input is turned off or unplugged. With the mic gain turned down to zero, or mic unplugged etc., and the RF power output tried at various levels, the noise is heard in a nearby monitoring receiver. (Even XMITR turned right down to its lowest output setting of 5 Watts still produced the noise)