modification to direct access the de-/modulator for 9k6 packet radio or xmit_id
remove battery.
dismount the tinplate which contacts the negative battery pole (4 skrews).
remove the two skrews that hold together the two shells. carefully separate the front shell. take care of the cables inside.
deskrew the pcb in the aluminum shell (3 skrews at the pcb's edges).
locate jack j201. pin 13 (undermost the the radio upwright) connects to the modulator. lift the pcb and solder a piece of wire (not too short) to this pin, the 9k6 tx-sigs will be feed in there.
guide the wire to the parts side and remount the pcb.
locate the demodulator q201 (tk10487m). the ic is placed underneath the crystal next to the squelch pot. pin 11 is connected to a 1k resistor. solder a wire to pin 11 of q201.
hhhhhhhh
h poti h smd capacitors are brown,
-- -- ========= resistors black
rr cc o o o
-- --
|c| -- --
1k cc
|c| ** -- <-- solder wire at location marked **
-----------
|r| i
i xtal
i
the two wires now should be lead to the outside. locate the 12v input jack, above it, there is a capacitor. above this capacitor there is enough room at mount a small jack in the side of the plastic front shell.
i decided to use 2 pins of an ic socket (high quality!). you only need to drill 2 holes with 1mm diameter, stick the pins through whose and fix the pins by heat and/or hotglue. solder the wires to the pins (least possible heat, the ht's plastic will melt elsewhise!).
warning. regardless what other modifications are telling you, do not dismount the display and keypad pcb! i did so, for better drilling (really not necessary!), the lcd and it's rubber connector fell off, and it took me a night to get the display back to life.
in case you turn on your radio, after the successful mod, an nothing happens, it has to be reset. switch it off and turn it on again whilst pressing the function key (obove ptt) and keypad 3. this will also extend the frequency range. the same procedure with other keypad numbers will give different frequency ranges.
this text was originally written in german by bernhard (db8bf), translated, shortend and enriched with own experiences with the hora c-455 ht.
please respect the regulations.
--- modification at your own risk! ---
73, joachim (dl1gsj)
转自
http://www.mods.dk/
