[Kenwood] TS-430 Vs. Lightning Bolt

Sun, 18 May 2003 16:47:19 -0400

Here is a challenge for all of you Kenwood experts.

I bought (cheap) a TS-430 that had experienced an altercation with a
lightning bolt.  The hit came through the PS-430.  The antenna was not
connected and the rig was not powered up.

The rig was turned on after the strike.  Unfortunately the power supply was
putting out about 25VDC at the time.

Results:

The receiver was dead.  The transmitter was dead.  The power supply was
putting out 25VDC.

What I have done so far:

Every transistor in the power supply was blown and several pc board traces
were vaporized.  It has been fixed.

The receiver audio amp, IC5 in the IF unit, was blown.  After replacing it,
the receiver worked fine.

Now on to the transmitter; there was RF power out of Q1 on the Final Unit.
Q2 and Q3 were shorted, Q5 and Q6 were shorted and R15 and R16 exploded.  I
replaced those parts.  Now I have RF on the bases of Q2 and Q3, but no power
out of them.

Looking closer at Q2 and Q3 I discovered a strange inconsistency between the
Kenwood schematic and reality.  The transistors are indicated as 2SC2509.
The schematic shows the center pin of this TO-220 transistor to be the
emitter.  The schematic shows the emitters are at ground.  The pc board view
in the service manual, and the circuit board itself, have the center pin
(and tab) of the transistor at ground.

All of this is wonderful, except the center pin and tab of a 2SC2509 is the
Collector!  I called Kenwood service and asked about this.  The tech I spoke
with got rather huffy at me for implying that there was something wrong, but
about an hour later he called me back and said I was right, there was
something strange going on.  His suggestion was that I order the parts from
Kenwood.

Does anyone out there have any experience with replacing these driver
transistors?  Has anyone noticed that the Kenwood schematic has the emitter
and collector of these transistors switched?  Does it really matter?

What else could be wrong with the transmitter?

Clues?  Suggestions?  Advice?

Thanks

Joe DiPietro

[email protected]

---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.481 / Virus Database: 277 - Release Date: 5/15/2003