Kenwood TS-430S Restoration- Changed 125 Capacitors!
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- čas přidán 23. 11. 2022
- K_8_b_y_p@IEEE.ORG
#ham #hamradio #hamantenna #arrl #ts430
NOTE: THE PA FAN COMING ON WAS MOSTLY ELIMINATED WITH A 12 VOLT, 60 AMP SWITCHING POWER SUPPLY! The PA was starving for CURRENT with a 30 amp supply.
Difficult job, worth the trouble. Fantastic rig, superior RX audio, much better than the new Yaesu all digital. The SSB speech processor makes a huge difference on the air, much higher power.
Replacing 125 parts requures a special process like in manufacturing to avoid mistakes that can cause damage.
Be careful with these old brown boards, very easy to damage them, theyre softer than the newer fiberglass FR-4 and wont take as much heat.
Also see N1SCAs teardown video... • YEASU FT- 757GXMK1 TEA...
and, view of PA board where the TO-220 devices had loose screws:
• Video Kenwood TS-430S ... - Věda a technologie
Kindly advise:
I extracted the output filter board of a TS-430S to work on it.
Issues:
1. Intermittent low rx (probably "dirty" relays). It appears they are all sealed (except the tx/tx relay).
I tried using a "wetting voltage" as described in a Kenwood service bulletin, but there is still intermittent loss of rx, especially on 10m.
2. One of the inductors (L41) is shorted.
3. How do you test a diac (D18)? (It reads short circuit in both directions.) Apparently it is for overload/surge protection.
4. The S meter reads extremely low. I failed to recalibrate S9 (even with the trim at maximum, it doesn't reach 9).
Expert advice, such old equipment is NOT a repair. It MUST be restored.
Resist the urge to chase multiple apparently unrelated problems.
BADLY wrong starting point to remove that board to address weak RX, the correct way is connect the antenna onto the first RF amp on whichever main board its on, instead of removing that difficult to get at relay board.
*Minimum total recap ( electrolytics) THEN go looking for any remaining problems. Also replave the 7805 regulator for the microcontroller.
Flaky power supplies can cause all kinds of strange problems.
A broken coax from a mixer caused intermittent RX in my 430.
Diacs cant read shorted, they are a bi directional voltage drop. Might be something else in parallel with it. In circuit testing is difficult...