|Introducing 'Ugly' Construction
Those with lots of experience of building homemade rigs will have no trouble
building the transmitter into a smart box. Those with less experience
would, perhaps, benefit by starting with a simpler approach. A 'bird's nest'
version can be constructed quickly on copper-clad board using 'ugly'
construction techniques. This is exactly what I did when I made the
prototype transmitter section of this little transmitter (see picture
below). It didn't look very pretty, but that really didn't matter -
the important thing was that it was possible to use the prototype
to test the design - and also work GW3UEP - my first QSO on QRPP!
And click this thumbnail for a close-up of the main components:
For more information about ugly construction techniques, click here.
More initial testing
November, I carried out some more tests using the following set-up:
The picture shows the K2 receiver; the receive converter (the receive
section of a Super-Sixty); a much-modified ETM-8C electronic keyer;
12v battery supply; and the bread-boarded QRPP TX. Using a G5RV
antenna, I worked the following stations around mid-day:
Richard, G3CWI in Macclesfield (185 km). Sent 599, received 569
Ian, G3TLH in Exeter (? km, 5 watts). Sent 579, received 579
George, GI4SRQ in Armagh (396 km, 5 watts). Sent 56/79, received 339
Peter, G3TJE in Highbridge (68 km, 5 watts). Sent 569, received 449
Ian, G3TLH in Exeter (? km, 500 mW). Sent 579, received 559
I later received an emailed report from Norman, GM4KGK (IO68VE, 761 km) to say that
he had also heard my signals. Not only that, but Norman had also
recorded some of my 'CQ' call!
Click here for
a .WAV file (370 kB) of Norman's recording of my CQ call, and the reply
from Ian G3TLH (5 watts). (You will need to turn the volume up to hear
my weak signals - but they are definitely there!)
The transistor may be obtained from either of the following suppliers:
1) Grandata Limited, K.P. House, Wembley, London, HA9 0HB
Tel: 020 8900 2329 Fax: 020 8903 6126
2) Sycom, PO Box 148, Leatherhead, Surrey, KT22 9YW
Tel: 01372 372587 Fax: 01372 361421
(Also a good source for loads of specialist components for the home-brewer.)
The HC25 crystals and sockets may be obtained from:
QuartSlab Marketing Limited
PO Box 19
Tel: 01322 330830
The crystal used was made to 'Specification E', 5.28000 MHz.
Feedback from other constructors