Allstar Nano Node Construction

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.

Nano Node - USB FOB/Transmitter Module Schematic

Nano Node – USB FOB/Transmitter Module
Schematic (updated 12/20/2014)

These modules do need additional filtering. I will be posting a link or provide additional information regarding the output filter.

Nano Node using Modified USB Audio FOB and an 818 UHF Module.

Nano Node using Modified USB Audio FOB and an 818 UHF Module.

The audio FOB shown above was modified based on the following article by Doug, WA3DSP:

http://www.crompton.com/hamradio/usb_fob_modification/

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:

allstar_node

Links

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:

http://crompton.com/hamradio/818_transceiver_module/

URI USB Radio Interface Link:

http://www.dmkeng.com/Products.htm

Audio FOB Modification Links:

http://www.crompton.com/hamradio/usb_fob_modification/

http://www.repeater-builder.com/projects/fob/startech-fob.html

KP4TR – great idea for a simple enclosure:

http://kp4tr.org

Final Notes

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.

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