N0ZYC Hybrid Attenuator
2020.11.03


materials:
- KC9ON offset attenuator kit
- wlaniot 3.15"1.97"1.57" extruded aluminum project box
- 2x BNC bulkhead jack, grounded
- M-M BNC adapter
- 2ft RG1.13 micro coax
- low profile 3P4T rotary switch
- knob for rotary switch
- 7.4v LIPO pack with USB charger
- 2x 41ohm 1/4w resistor
- 2x 49ohm 1/4w resistor
- 10ohm 1/4w resistor
- 1ohm 1/4w resistor
- 2mhz xtal
- assorted small gauge stranded wire


tools:
- soldering iron, solder, wire cutters, wire strippers, xacto knife, small needlenose pliers, etc
- drill press
- assorted drill bits
- hot glue gun
- kapton tape (optional)


next steps:

- solder OA power wire jumpers to selector
- reinforce power jumpers on selector with hot glue
- strip and prep battery power wires
- install fuse inline with battery (+)
- protect exposed battery wires
- fit test battery, OA, selector, and pot
- cut and verify power wire and coax lengths
- remove all

- temporarily solder BNCs and power
- test operation of THRU, 20, 40, and OA
- get pictures
- unsolder BNCs and power
- protect exposed battery wires

- copper tape over holes in case
- verify copper tape is grounded
- fill holes on outside with hot glue

- install selector, pot, and OA
- fully install LED
- hot glue battery and charge port in place (with charger attached as guide)
- splice in battery, protected with heat shrink tubing
- verify OA powers on
- test charger
- reinforce LED with hot glue

- mark radio end plate for charger access
- cut notch in radio end plate for charger
- temporarily close enclosure and verify charger access

- open enclosure
- solder BNCs
- reinforce BNC coaxes with hot glue (glue to end plates)
- get pictures
- close enclosure
- test operation of THRU, 20, 40, and OA
- test operation of usb battery charger


versio 2 upgrades:
- replace LED with RGB LED, power G / R / B for 20dB / 40dB / OA attenuator status (remember not to fold down selector pins)
- change rotation direction of OA pot