A compact 5 band QRP SSB transceiver in SMD technology

A compact SSB transmitter/receiver will be presented. This unit covers 5 bands within the amateur radio spectrum (3.5, 7, 14, 21 and 28 MHz). Receiver is a single conversion unit with an interfrequency of 9 MHz. Transmitter uses 5 stages and has got a power level of 10 watts PEP output.

Frequency generation is done by integrated ready made modules like an AD9850 as VFO, and an Si5351 as LO. Microcontroller is an Arduino Pro mini AtMega328 driving a colored TFT LCD with ST7735 chipset.

The whole device has been constructed in SMD but can also be setup by using “thru hole” techniques or mixed installations.

The whole is unit is built into into a mounting frame of aluminum sheets of standardized width. Size if the whole radio is 17 x 12 x 5 centimeters. It is, to a certain degree, the “Little Brother” of the “Mini6“-Transceiver that had been designed mainly for experimental purposes.

Description

Multiband QRP transceiver projects are a challenging undertaking for the radioamateur. The even more challenging matter is to build it as neat as possible.

The “Mini6” transceiver has been an interesting step which made me learn a lot of things. But it is a much bit too bulky for my needs (producing compact and lightweight portable gear for traveling, hiking etc. ) On the other hand I found that I don’t really need 160m installed in the radio (due to antenna problems here at my site) which defined the next multibander having a “classical” (i. e. 70s) layout with 80, 40, 20, 15 and 10 meters.