Back to the roots - the BTR18, a project of German QRP Club DL-QRP-AG.
Design: Peter Solf, DK1HE
Coordination and construction folder: QRPeter, DL2FI
For a long time we have been discussing the idea of building a good, small transceiver that is as simple as possible, but at the same time avoids the mistakes of its predecessors, which can hardly be counted. A specially designed booklet will help you to understand each classic receiver and transmitter function group (yes, it's been a long time since we learned to take the exam :-)
From the beginning there were some parameters that we could all realize in the BTR18:
Small, light and extremely low power consumption - 10cmx10cmx5cm RX about 20mA, TX about 600mA at 5W output
Battery operation from Eneloop Mignon possible - Approx. 3-4W output depending on residual battery voltage
Built-in battery control Green/Yellow/Red = full /medium/ say good bye, go QRT.
Robust, 5W PA that survives short circuits or missing antennas - Mitsubishi RD6HHF1 in the PA,
SWR display during transmission via 2 LEDs
Radio operation must be possible without "torture", so the RX must be good - 0.2µV sensitivity, 4-pin quartz filter, fine "analog" sound, soft keying, TX monitoring of your own signal, very low noise.
No "plopping" AF by AGC - Real HF manual control > 80dB
No restriction of adjustability as with pulled quartz oscillators - very stable clapp oscillator over the entire CW range of the band
Every KW band possible - We start with 40m because there is activity possible at any time of day or night. The other bands will follow
As little SMD as possible, if at all, then only in sizes that are controllable by everyone but pre-assembled SMD possible.
No "crutch solutions" in favor of the price like e.g. SMCC as filter inductors or small power transistors parallel in the output stage.
Every beginner must be able to set up the txvr completely safely. Detailed construction manual divided into functional groups which can be tested individually.
Every beginner should be able to understand all functional groups of the txvr. In addition to the manual, very detailed descriptions of the functions. During building time we organize group discussion at www.qrpforum.de and weekly meeting on a particularly furnished Teamspeak channel at www.funken-lernen.de
Optionally the flexible PK4 keyer is equipable