This project describes NBFM Triband VHF transceiver that I use for general purpose simplex and repeater operation. The basic DSP is identical to the simplex VHF NBFM transceiver project: VHF NBFM Transceiver. The primary difference in the projects is the addition of repeater capability, with selectable splits, CTCSS tones, and frequency offsets. All of these changes are accomplished via the Control Section of the flowgraph.
For the sake of simplicity, and to reflect the primary changes between the two NBFM transceiver projects, Control Section of the flowgraph will be the only component illustrated here. Note the Control blocks across the top tier of the flowgraph. The titles and some of the parameters are visible in the screen capture.
Detailed examination of the properties for each Control block is best examined after downloading and opening the .grc files: NBFM Triband VHF Transceiver .grc
A the overall functionality of this project is illustrated in the Operating GUI that appears after the .grc file is executed. Visible on the Operating GUI are the multiple options for frequency control, frequency split, CTCSS choices, Squelch level, etc.
The .grc file for this project is available here: NBFM Triband VHF Transceiver .grc