Modifications for the Kenwood
TS-2400
19-07-1998 TS-2400
out-of-band mod
Locate the rx unit.
Cut the diodes D32 and
D33 located inside the DTMF ic.
Is this simple or what?!
19-07-1998 TR-2400
Unwanted Noise: Tone or burst at TX
2-13-80
For complaints of a tone burst type noise, or
simply a noise, at initial key down, suspect either a broken losse component, or
incorrect valued component on the RX TX unit.
On the RX TX unit, Q16
emitter, check C82, a 33 uf tantalum cap for broken connection.
If you
find a 22 uf cap at C82 replace it with a 33 uf cap.
19-07-1998 TR-2400
Display or Keyboard trouble
2-20-80
Display
An intermittent or blank digit
may be caused by either a broken lead, or intermittently shorting lead on the
PLL unit.
On the PLL unit, look in the area of Q12, the touchtone
generator. Between Q12 and the board edge locate the D1-D4 lines. Inspect this
area for either an open (Broken) lead, or shorted (pinched) lead. Repair as
necessary, and check lead dress before reassembly.
Keyboard
An
intermittent or inoperative keyboard row or column may be caused by a torn or
pinched lead, or a cracked diode.
Again, in the area of Q12, inspect the
"T" and "Y" lines for shorts or open connections, and inspect diodes D19-D26 for
physical breakage.
19-07-1998 TR-2400 RX
low, INtermittent, or distorted
2-20-80
For any of the above complaints, suspect a
broken loose component in the RX IF or audio output circuit on the RX TX unit.
Simply pull up on the leads and resolder.
Adjacent to Q9, the audio
output IC, find C49, a 1uf cap. If broken loose from the board, audio output may
be down, while current consumption may be up from the normal 30mA to about 100mA
due to the audio output amp oscillating.
Adjacent to L10, the
discriminator, locate C33, a .033uf cap. If this component is broken loose,
audio output may be up approximately 6 dB with excessive high frequency audio
response.