Projects for the amateur radio engineer. Hardware, software, electronics and test equipment for the amateur community.
When the project of building a very small transceiver was accomplished 4 years ago, I still lacked lots of skills in setting up electronic circuits using SMD technology. The radio’s craftmanship had been more or less defective to a certain degree (there were still lots of things to learn when using SMDs on Veroboards), the…
Abstract The 10 watts peak envelope power linear transmitter for single sideband operation will be examined. Test conditions are: 10 watt pep on every band, rf line terminated with 50 ohm dummy load, input audio two-tone signal identically applied for each measurement. Measurements have been taken with RIGOL DSA815 spectrum analyzer, RIGOL DS1054 digital oscilloscope…
Abstract This article will describe some design ideas that might be helpful in case the objective is building a medium power (i. e. 10 to 20 watts pep) radio frequency amplifier using a very compact design The whole final amplifier for the broadband linear transmitter had to be packed into an area whose size is …
Abstract The transmitter for this transceiver is designed to deliver a peak envelope power (PEP) of 10 watts on all bands from 80 to 15 meters. Due to its purpose (SSB amplification) it is a linear amplifier. The circuit is equipped with 5 stages where the first one is a gain control stage containing a…
Sorry for having deferred the description of the transmitter. The recent days I have been concerned with a new frequency layout for the transceiver. I found that the 17m-band could be an interesting topic because when tuning on internet based SDR pages the last days I saw many strong signals appearing. This might be due…
Introductory article of this project This is some sort like “Copy & Paste”, a useful mean if you want to create a doctorate, like the former German Minister of Defense Mr Guttenberg once did. 😉 I don’t want to achieve a doctorate but the receiver of this radio is more or less the same I…
As mentioned in the introductory article to this radio the digital components in this transceiver are pre-manufactured modules that have only been put together in a more or less sensible way. ;-). These modules are: AD9850 as variable frequency oscillator (VFO), China made no-name board, Si5351 as local oscillator (LO) produced by “Adafruit”, Arduino Pro…
Follow-up articles published so far: Digital and analog main units: VFO, Local oscillator, Display, TX-Gain control Receiver unit Transmitter unit Abstract 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…
This unit basically consists of two parts: SSB-Generator and TX-mixer TX-power amplifier stages The SSB-Generator and TX-Mixer Board After having built this respective board with two NE612 ICs (one for DSB generator, one for the TX mixer) I was not satisfied with carrier suppression of the DSB generator. It turned out as only 40dB. Afterwards…
This short article will describe the adapter board that is connected to analog data sources and that is converting the respective voltage data into suitable voltage levels for the ADC inputs PA0:PA4 at the microcontroller: The following data will be converted and later shown on the display: User keys (Key1:Key3) TX power measurement PA temperature…