====== maintenance ======

transcribed from [[https://media.ccc.de/v/32c3-7153-rad1o|rad1o++ talk at 32c3]], referencing
[[https://events.ccc.de/congress/2015/Fahrplan/events/7153.html|the slides]] starting at page 38

===== bugs =====

==== interferences ====

* sample clocks are at 2 and 20MHz
* doubled at 4 and 40MHz
  * => interference spikes at 80, 120, 160, 200,
* goes away at 400MHz

==== missing high pass filter ====

* unpopulated in big rf area (FL301)
* RX/TX over 2.75GHz not possible
* solution 1:
  * when only RX: just bridge it
* solution 2:
  * populate it yourself

==== backlight ====

* on some rad1os the backlight might stay on and drain battery
* => unplug battery

==== onboard antenna ====

* should be at 2.48GHz-2.5GHz
* measured at 2.35GHz

==== power supply ====

* 1st usb port always used to suck power (up to 700mA for TX)
* 2nd usb port is limited to 475mA
* solution 1: patch hackrf to use 2nd port for data
* solition 2: build usb cable with seperate power connector

==== external clock input ====

* clock input is wired to ground, connection below chip
* solution: solder it on the pad of the crystal and supply with 27MHz

==== isp pin floating ====

* under battery an isp header can be soldered on
* one of the pins should be pulled high, but isnt (see page 52)
* if it is low, the rad1o wont boot

==== reset pin ====

* connecting anything to that pin will trigger reset
* 12k pull-up is already there, but it's still touchy

===== maintainence ======

==== broken display ====

* replace with one from a Nokia 6100

==== no audio input/output  ====

* check audio connector solder joints
* move plug around a little bit

==== bad power switch ====

* remove it
* put a jumper on there

==== working, but no data ====

* check with other/shorter usb cable

==== display flickering ====

* charge battery

==== data transfer takes very long ====

* yea it's just slow flash
* wait
* use "safe eject"/sync

==== rgb leds ====

* resistors populated incorrectly/unpopulated
* bug documented incorrectly
* just bridge at 3 places (see page 60 and [[leds#how_to_supply_the_leds_with_power|RGB LEDs]])

==== antenna connector ====

* when soldering on an antenna
* dont bridge left 2 big pads
* they are very close together
* would bridge power supply

==== Bias-T ====

* to power an antenna through hackrf software
* put "large" inductor ("like 10μH") onto the smaller pads below the SMA pads (see page 62) (dont bridge with antenna pads)
* if your antenna has an DC path, it might burn out the inductor (see page 63)

==== protection ====

* display and some inductors (especially rf area) are very fragile
* shield it
* put a case on it

===== performance improvements =====

==== PLL ====

* code improved to for better performance <2.15GHz
* just upgrade your f1rmware

==== interferences ====

* 10MHz reference output disabled in software (because most people wont use it anyway)
* transceiver and PLL are now both at 40MHz
* => no extra spurs caused by 50MHz PLL clock
* just upgrade your f1rmware