Related Manuals for G-QRP Club Limerick Sudden
Summary of Contents for G-QRP Club Limerick Sudden
- Page 1 The G-QRP Club The Limerick Sudden 20m Transmier Kit Circuit design – George Dobbs G3RJV PCB design – Rex Harper W1REX Kit – Graham Firth G3MFJ Manual – G3RJV and G3MFJ...
- Page 2 Founded in 1974, the G-QRP Club is the largest QRP Club in the world. The club exists to promote interest and growth in low power amateur radio communication (5 watts or less). Member- ship is open to any licensed radio amateur or short wave listener anywhere in the world.
- Page 3 Transmier Overview The Limerick Sudden Transmier is a simple circuit for a reliable QRP transmier. Alt- hough crystal controlled, the oscillator stage (T1) is a Variable Crystal Oscillator (VXO). The crystal supplied is a fundamental frequency crystal on 14.060MHz, the QRP calling frequency on the 20 metre band, although other frequencies are available for the CW end of this band.
- Page 4 G-QRP Club logo in the centre right. Top is actually the Rear of the finished board, and boom is, of course, the Front.
- Page 5 Winding toroidal coils is easy. It just requires pa4ence and care. TR1 uses the black core with the gold wire for the main winding. The 25 turns require 15” of wire. Each 4me the wire passes through the hole (including the first 4me) it counts as ONE turn.
- Page 6 TR1 is mounted ver4cally in the centre of four pads. The primary (larger) winding is soldered to the top right pad and the boom le6 pad. The link (5 turn) winding to the other two pads. The transmier is built in two sec4ons; the first being the le6- hand side of the circuit diagram as far as R7.
- Page 7 The key jack socket The socket is a 3.5mm socket to be used with a 3.5mm mono jack plug so one of the connec4ons, (which is a switch con- tact), is unused. It is a good idea to cut off the unwanted sol- der tag to avoid confusion.
- Page 8 Add the side cheeks This is a good 4me to solder the “side cheeks” into place either side of the main board. These are designed as fixing plate for the enclosure. Adding the side cheeks at this point does mean that the fixing of the front and back panels of the receiver is much easier.
- Page 9 Complete circuit diagram...
- Page 10 Tes9ng the first sec9on Tes4ng the transmier at this stage requires a Diode Probe. All the parts are provided for making such a probe as shown in the picture. The diode probe is built “Manhaan- style” by aaching a strip of five pads to the top le6-hand corner of the printed circuit board material using super glue.
- Page 11 The crocodile clips are easier to aach to the ends of the yellow and green wire. Prize the clip open a lile and slide off the plas4c cov- ering. The wire can be soldered to the clip and held in place by the crimps at the end. Remember –...
- Page 12 Now, the rest of the transmier. The final amplifier Firstly, wind the coil L2. This is 5 turns on a FT43-2402 binocular toroid. Each turn goes through both holes of the core, and you should end up with it looking like this. Use the soldering iron as described earlier to 4n the leads of this inductor.
- Page 13 Next, we fit all the capacitors in the filter, followed by the inductors. A good plan is to mount C12 - C15 and C18, then mount L5, followed by L4 and L6. Here is a picture of the completed board so far. The layout of the printed circuit board.
- Page 14 The back panel. Firstly, mount the three sockets on the back panel – the antenna socket, the receiver aerial socket and the power socket. The antenna sockets The antenna socket (ANT) is a single hole fixing phono socket, as is the RECEIVER socket. These require two wires to be joined to the ANT pads on the main board and we will connect these in a moment.
- Page 15 Wiring the back panel to the main board. Now, if you place the rear panel behind the main board, you can connect the other end of all the wires – green to R-MUTE, orange to K-MUTE, black to the outer solder tag of the antenna socket, and the blue wire to the centre connec4on.
- Page 16 Connect the yellow clip lead to the centre of the ANT socket and the green clip to the ground of the ANT socket and the red and black leads to a voltmeter. Connect the 12 volt supply, leav- ing the NET SW switch upwards, and press the Morse KEY down. Read the output voltage. The voltage is the peak to peak measure- ment.
- Page 17 Finally – the case The case parts should now be soldered together – the important point here is that the sides must be at right-angles to the top. Again, use the single blob technique un4l you are sa4s- fied with the angles – it is beer if you do not solder right up to the front of the lid as the case overlaps the front to give a hooded effect, and if you solder right up to the front, the case may not fit as well.
- Page 18 Value Markings Resistors Yellow, purple, orange, gold Yellow, purple, brown, gold Brown, red, black, black, brown Red, red, red, gold Yellow, purple, brown, gold Brown, black, black, gold Orange, orange, black, gold Brown, black, red, gold Yellow, purple, orange, gold Brown, black, red, gold Red, red, red, gold Brown, black, orange, gold...
- Page 19 Semiconductors 2N3904 Oscillator 2N3904 Driver 2N3866 (4-247 CG9949) PA (spare included) 2N3906 Keyer 2N7000 RX series mute 2N7000 voltage inverter 2N7000 RX parallel mute 1N4148 For net switch 1N5711 RX parallel mute 1N5711 RX parallel mute 1N5711 Probe detector 1N5711 Probe detector 33v zener diode (BZX55C33) PA protector...
- Page 20 The finished transmier (This is a picture of the 30m version of the kit) © G-QRP Club 2010/11/12/14/15/16 V2.7 May 2016...