Even in times of modern all band technology, there is a continuing interest in monoband QRP CW transcievers. Most are presented as easily and quickly built kits, and are thus well suited for both newcomers and oldtimers. The experience of trouble free QSOs with a home built, simple transceiver won´t compare to using even the most expensive "yen box": it gives a feeling of going back to the roots of ham radio.

Available kits are roughly of two kinds:

1. Fun transceivers", designed for QRP use and a minimum of complexity and component count.

2. Monoband transceivers with a more demanding technique and larger complexity, but with a comfort of use and performance comparable to more expensive equipment.

Kits in category 1 usually have direct conversion or single conversion receivers. Many of these are good constructions, though. They often miss sensitivity, and as their oscillators often are based on VXCOs, they usually have a small frequency variation. Due to little RF selectivity, they often have intermodulation problems from BC transmitters on the 40 meter band. RF attenuator potentiometers relieves this a little, but at the price of reduced sensitivity. No or bad AGC forces the operator to adjust the AF output volume. Because of the increasing demands on the construction, most kits are not offered in version for higher bands than 20 meters.

Kits in category 2 take more time to build, due to a larger component count and more complex design. Trimming of these kits is also more complicated. Many newcomers won´t build one of these kits, as they want to be QRV quickly and easily.

The little Sparrow is the German QRP Club´s try to combine both categorys in on transceiver. The result is as we proudly feel a little revolution. ALL SW Bands up to 50 MHz, Full 5 Watt, DDS controlled.

Design                                   Peter, DK1HE
project coordinaton, Manual,      Peter, DL2FI
Prototyping, fault finder            Juergen, DL1JGS
DDS Programming                     Wolf, DL2WRJ
English translation                    Peter, OZ5DW

The Sparrow project has been started in July 2002. We actually ship 40 Meter, 30Meter, 20Meter and 17 Meter Versions

15 Meter, 10Meter, 80m and 6Meter will follow later on, depending on request.

TECHNICAL DATAS:

- All Amateur Radio Bands 80m to SIX Meter possible
- DDS VFO, as stable as crystal control
- High RX sensitivity (typ. 0,3µV)
- High RX input selectivity (good intermodulation characteristics on 40 meters)
- 8 pole Cohn Filter with 400Hz bandwith
- Combined dynamic range of AF and IF of more than 90dB
- QSK
- RIT, XIT
- Frequency read out in morse
- possible addition of an external frequency display (with IF offset)
- possible addition of a relative signal strength read out
- chirp reduction
- PA output adjustable to  >> 5W
-heavy duty PA transistor (2SC1969)
- direct monitoring of transmitted signal
- High suppression of spurious signals  (better -50dBc)
- low power consumption (RX=80mA; TX=630mA at 5W Out)
- reduction of external wiring through use of printed circuit connectors.
- easily reproduced toroid inductances
- standard casing (Teko CH2) with printed front panel sticker

The complete manual in english language can be downloaded here 
  It is a 2.7 MByte PDF

Manual 80m version August 8. 2005

Manual 40m version August 8. 2005

Manual 20m version August 8. 2005

Sparrow TX

The Anaylyzer shows the keyed 7MHz signal at the left side. at the right you see the very little harmonic at 14 MHz (better -50dBc at 5 Watt out into 50 Ohm.