Class A Amplifier from Experimental Methods in RF Design (EMRFD) Fig. 2.29.
I found a way in LTspice that you can simulate several signal drive levels to give various output waveforms.
Here the graphic shows at 20mV AC drive a nice sinusoidal O/P on the collector. As we increase the drive level the transistor goes into saturation and the output wave form appears clipped as the collector voltage appoaches the Voltage supply at 10V and thus the causing the collector curent to drop to zero. At the exteme input drive level the collector has dropped below the base voltage and the transistor is shown saturated for the bottom part of the curve.
It was nice to model an amplifier this way to show the effect of non-linearity behavior. The Spice models shown are similiar to the curves shown in EMRFD Fig2.30.
The spice model includes a Spice directive that basically switches in each voltage source given by the .param and .step function. The B1 symbol is an arbitary behavioural voltage source symbol and not a voltage source symbol which caught me out.
Thursday, 18 June 2009
Wednesday, 17 June 2009
WSPR
WSPR - Pronounced whisper stands for Weak signal propogation network.
WSPR is basically a propogation network of low power Beacons operated by hams all over the world.
I tried it out for the first time tonight after seeing a posting on a Web page on how easy it was to set-up. As I already had an interface box to connect up my Icom IC-735 to the PC for PSK31 I thought I would give it a try. The software to run WSPR can be found here on K1JT's Website.
After downloading it, you need to configure the Setup - option page at the top of the program. Details can be found on the WSPR program Help page. Next You need to ensure that your computer is correct to within 1 sec for the program to decode the incoming received signals. On Windows XP that is done by clicking the time at the bottom of the desktop and selecting adjust/date time. In the Date and Time properties box click the Internet time tab and then press update to synchronise the clock to one of the universal time standard servers.
The radio receive frequency has to be manually set to the default frequency shown on the WSPR program as there is no CAT control to the transceiver. To select the Transmit frequency just double click on the water fall display, I usaully set the T/R cycle to 20%. Just this evening alone I received a report from VK wow!!. My transmit power was only 1 Watt into a 102ft Doublet 30ft high.
My tribulations in connecting my Laptop upto the Transceiver is another story, and hopefully will document in a further blog entry.
G4ILO has written a very good write up and tutorial on operating WSPR.
This is my signal received by other stations.
This is my report to other stations
WSPR is basically a propogation network of low power Beacons operated by hams all over the world.
I tried it out for the first time tonight after seeing a posting on a Web page on how easy it was to set-up. As I already had an interface box to connect up my Icom IC-735 to the PC for PSK31 I thought I would give it a try. The software to run WSPR can be found here on K1JT's Website.
After downloading it, you need to configure the Setup - option page at the top of the program. Details can be found on the WSPR program Help page. Next You need to ensure that your computer is correct to within 1 sec for the program to decode the incoming received signals. On Windows XP that is done by clicking the time at the bottom of the desktop and selecting adjust/date time. In the Date and Time properties box click the Internet time tab and then press update to synchronise the clock to one of the universal time standard servers.
The radio receive frequency has to be manually set to the default frequency shown on the WSPR program as there is no CAT control to the transceiver. To select the Transmit frequency just double click on the water fall display, I usaully set the T/R cycle to 20%. Just this evening alone I received a report from VK wow!!. My transmit power was only 1 Watt into a 102ft Doublet 30ft high.
My tribulations in connecting my Laptop upto the Transceiver is another story, and hopefully will document in a further blog entry.
G4ILO has written a very good write up and tutorial on operating WSPR.
This is my signal received by other stations.
Timestamp | Call | MHz | SNR | Drift | Grid | Pwr | Reporter | RGrid | km | az |
---|---|---|---|---|---|---|---|---|---|---|
2009-06-17 23:20 | G0BON | 14.097089 | -24 | -1 | IO91qm | 1 | VK8CH | PH57 | 13894 | 63 |
2009-06-17 23:20 | G0BON | 14.097088 | -22 | -1 | IO91qm | 1 | DH5RAE | JN68pv | 1031 | 101 |
2009-06-17 23:20 | G0BON | 14.097091 | -26 | -1 | IO91qm | 1 | K3SIW | EN52ta | 6357 | 298 |
2009-06-17 22:50 | G0BON | 14.097088 | -19 | -1 | IO91qm | 1 | VK8CH | PH57 | 13894 | 63 |
2009-06-17 22:50 | G0BON | 14.097085 | -24 | -1 | IO91qm | 1 | DH5RAE | JN68pv | 1031 | 101 |
2009-06-17 22:22 | G0BON | 10.140241 | -24 | -1 | IO91qm | 1 | RA1AMO | KO59cw | 2119 | 52 |
2009-06-17 22:16 | G0BON | 10.140242 | -28 | -1 | IO91qm | 1 | RA1AMO | KO59cw | 2119 | 52 |
2009-06-17 21:52 | G0BON | 10.140237 | -27 | -1 | IO91qm | 1 | RA1AMO | KO59cw | 2119 | 52 |
2009-06-17 21:10 | G0BON | 10.140206 | -26 | -1 | IO91 | 5 | W3CSW | FM19kd | 5827 | 288 |
This is my report to other stations
Timestamp | Call | MHz | SNR | Drift | Grid | Pwr | Reporter | RGrid | km | az |
---|---|---|---|---|---|---|---|---|---|---|
2009-06-17 23:00 | DL8BB | 14.097060 | -10 | 0 | JO41ul | 5 | G0BON | IO91qm | 715 | 274 |
2009-06-17 22:56 | AI4RY | 14.097119 | -20 | 1 | EM72go | 5 | G0BON | IO91qm | 6897 | 45 |
2009-06-17 22:54 | K3SIW | 14.097198 | -10 | 0 | EN52ta | 1 | G0BON | IO91qm | 6357 | 48 |
2009-06-17 22:54 | WB4KLJ | 14.097182 | -25 | 0 | FM18ku | 2 | G0BON | IO91qm | 5874 | 49 |
2009-06-17 22:43 | K3SIW | 14.097197 | -14 | 0 | EN52ta | 1 | G0BON | IO91qm | 6357 | 48 |
2009-06-17 22:43 | WB4KLJ | 14.097181 | -24 | 0 | FM18ku | 2 | G0BON | IO91qm | 5874 | 49 |
2009-06-17 22:41 | UT7UA | 14.097181 | 0 | 0 | KO50ji | 5 | G0BON | IO91qm | 2188 | 286 |
2009-06-17 22:35 | UT7UA | 14.097182 | 0 | 0 | KO50ji | 5 | G0BON | IO91qm | 2188 | 286 |
2009-06-17 22:35 | AI4RY | 14.097121 | -20 | 1 | EM72go | 5 | G0BON | IO91qm | 6897 | 45 |
2009-06-17 22:35 | DF6MK | 14.097105 | -9 | -1 | JN68ik | 5 | G0BON | IO91qm | 1011 | 295 |
2009-06-17 22:33 | W3PM | 14.097158 | -20 | 0 | EM64or | 5 | G0BON | IO91qm | 6817 | 45 |
2009-06-17 22:25 | IQ4DJ | 14.097085 | -9 | 0 | JN54ks | 0.05 | G0BON | IO91qm | 1134 | 316 |
2009-06-17 22:02 | G8IHT | 10.140122 | -19 | -2 | IO94gi | 10 | G0BON | IO91qm | 320 | 170 |
2009-06-17 22:00 | IQ4DJ | 10.140186 | +5 | 0 | JN54ks | 1 | G0BON | IO91qm | 1134 | 316 |
2009-06-17 21:58 | IQ4DJ | 10.140187 | -4 | 0 | JN54ks | 0.05 | G0BON | IO91qm | 1134 | 316 |
2009-06-17 21:56 | IQ4DJ | 10.140188 | +6 | 0 | JN54ks | 1 | G0BON | IO91qm | 1134 | 316 |
2009-06-17 21:54 | OE1IFM | 10.140273 | -9 | -1 | JN88df | 1 | G0BON | IO91qm | 1263 | 293 |
2009-06-17 21:54 | IQ4DJ | 10.140188 | -3 | -1 | JN54ks | 0.05 | G0BON | IO91qm | 1134 | 316 |
2009-06-17 21:38 | OE1IFM | 10.140166 | -6 | 0 | JN88df | 1 | G0BON | IO91qm | 1263 | 293 |
2009-06-17 21:18 | IQ4DJ | 10.140206 | -15 | -1 | JN54ks | 0.05 | G0BON | IO91qm | 1134 | 316 |
2009-06-17 21:16 | IQ4DJ | 10.140207 | -4 | 0 | JN54ks | 1 | G0BON | IO91qm | 1134 | 316 |
2009-06-17 21:16 | G7NKS | 10.140137 | -22 | -1 | IO92ub | 10 | G0BON | IO91qm | 64 | 201 |
2009-06-17 21:14 | IQ4DJ | 10.140208 | -14 | 0 | JN54ks | 0.05 | G0BON | IO91qm | 1134 | 316 |
2009-06-17 21:12 | IV3DXW | 10.140265 | +1 | -1 | JN65qq | 2 | G0BON | IO91qm | 1214 | 307 |
2009-06-17 21:12 | IQ4DJ | 10.140210 | -6 | -1 | JN54ks | 1 | G0BON | IO91qm | 1134 | 316 |
2009-06-17 21:12 | G3NIC | 10.140199 | -23 | -1 | IO93rg | 5 | G0BON | IO91qm | 195 | 182 |
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