A repeater telemetry project is actually thought of , when , after much endeavor, the Punjab Amateur Radio Society (India) managed to get a License for setting up a VHF repeater in this area. The location of the repeater is at Sri Naina Devi, which is a hill temple town at an elevation of 4500ft. Furthermore, it is approximately near the confluence of three states (Punjab, HP and Haryana in INDIA) and Chandigarh UT. The only problem is that the area is quite remote and at least 3-4 hours of a hilly drive from most ham stations. so the repeater has to be unmanned and remote.
So there is a need to monitor its working parameters like SWR, Heatsink temperature, standby battery voltage, AC line voltage etc probably wind speed later. This would give the caretakers an indication when to get ready for a busy weekend on the hilltop.
There are probably readymade projects for this, but they are either exorbitant or not suited for amateur radio use. Luckily we have someone with a good experience in using microcontrollers, and hence we wish to embarked on this project.
Basically we are planning to take / connect various sensors to the Atmel microcontroller, which will take commands from a DTMF decoder connected to the repeater audio. The sensor output will then be translated to voice using a addressable ISD voice recorder, and fed to the repeater microphone input and also the PTT. We are facing problems interfacing an LM3914 based SWR meter and battery voltage monitor. Hence a thought of using a ADC chip (ADC0809) instead.
Now it is felt (suggested) that a separate UHF link (315 MHz) be used for general monitoring and control of the Remote Repeater Station. This would have the advantage of no interference with the operating of the repeater and yet have total control on it.
Now we have available technology to make it happen using fewer and better components to accomplish our goal.
For this we have short listed the following group of components for the job :
ADC0809 , MAX158, MAX197
We invite suggestion and contribution from visitors to this page
updated on 07 February 2002