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This relay, allows your stations signal to pass through, unprocessed to transmitter chain. When a CAP alertcode is active. DTR asserts pin 4 High on a DB9 RS232 cable with 5 Volts during the alert. When the alert is concluded, pin 4 goes low, allowing regular programming to pass through. At present this works with DB9 cables for GPIO. We would like to hear from anyone that has got this to work with a USB cable. In future, we will be adding this to GPIO headers on Raspberry Pi computers.
Parts List Open Broadcaster EAS Relay
Kit with diagram and assembly photos of a complete RS232 GPIO Switching Relay . Special Thanks to Pippin Technical supplier of parts in a kit form if that has any appeal for around $150 or the completed switching relay. Full assembly takes 2 +/- hours for all mounting, cable prep, soldering and testing with the OB Alert Player. Might take a bit longer for groups that have never built one before. Get a group together for a DIY maker space hands on training project.
Bill of Materials
|Item Description||Quantity||Item No.|
|Broadcast Tools LR-5 latching relay||1||LR-5|
|Hammond Box ABS GRAY 6.58”L X 4.21”W||1||HM225-ND|
|Neutrik 3 Pin Nickel Male Inline XLR||2||NC3MX|
|Neutrik 3 Pin Nickel Female Inline XLR||4||NC3FX|
|DB15(F) Connector and Shell||1||Shop Supplies|
|Semiconductor, Wiring and dressing||1||Shop Supplies|
Full assembly takes 2 +/- hours for all mounting, cable prep, soldering and testing with the OB Alert Player. Might take a bit longer for groups that have never built electronics projects before.
Internal View Pippin Technical Alert Relay
Completed Pippin Technical Alert Relay
Dave Currie of Faith FM Waterloo Ontario made this really professional EAS setup using a Intel NUC and a custom relay. Nice work Dave!
Why bother buying a 15.00 inline adaptor when you can make it yourself with a few parts and a soldering iron.
‘H’ or ‘T’ pads may also be fabricated to accomplish the same level of attenuation.For a balanced signal, use an H-Pad: input_impedance=30k Ω, output_impedance=10k Ω. The example below provides approximately -20dB of attenuation using resistors R 1/2= 12k Ω; R 2=3.3k Ω; R 3/2=3.3k Ω (ground wires should also be connected).