I have a preliminary schematic of the Allstar Nano Node. This is still under construction and I will be adding additional construction pictures as I progress through this project.
These modules do need additional filtering. I will be posting a link or provide additional information regarding the output filter.
The audio FOB shown above was modified based on the following article by Doug, WA3DSP:
I mounted it above the board using cut resistor leads to raise the board above the proto-board. This was similarly done with the transceiver module. There are small copper pads that I made with my punch from a single sided circuit board to insulate the PTT and COS lines and make a convenient junction point.
The three pin edge connector is for programming the module.
Here is the final result:
Doug, WA3DSP, has a 818 transceiver module page. His module mounted in an Altoid style tin and uses a 9 pin connector to interface with the URI – USB Radio interface. He also has information on filtering. The following is a link to his page:
URI USB Radio Interface Link:
Audio FOB Modification Links:
KP4TR – great idea for a simple enclosure:
I have been using the 818 transceiver modules for a while. One thing I noticed is that the receiver in the modules “crackles” with multi-path signals as if the receiver AGC is clipping. It sounds like a bad mic or connection. This occurs on all the modules that I have tested and does not matter what radio is transmitting to the module. I can’t explain this issue and I have also seen the same issue on my Baofeng UV-82 transceivers during receiving. The “crackling” is very noticeable and bothersome and does not matter how the module is programmed or if filters are enabled or disabled.