Subject: FL7000.mod
From: Howard Ryder 

FL7000.mod


Most Yaesu FL-7000 Solid State Linears have a hypersensitive protection
circuit that causes the "protect" to trip when no improper conditions exist.
This modification will desensitize the protection circuitry; but still allow
it to function when an improper condition exists.

The modification is as follows: 

   PROTECTOR  UNIT
     * REMOVE D7006  P/N HZ15-1L
     * REMOVE R7029  P/N J02245102
     * REMOVE R7033  P/N J02245104
     * REMOVE Q7004  P/N G3107331Q
     * ADD R7060 Resistor 10K 1/4w P/N J01225103 This resistor must be added
from pin 7 of Q01 (1/2 of AN6552) to pin 5 of Q7003 (1/2 of AN6552)after
removing R33 10ohms.I carefully snipped the lead in the center and put my
10K in series with the existing 10 ohm resistor.

POWER SUPPLY UNIT
     * REPLACE C8019  P/N K13179009  WITH  1uf 50VDC P/N 59V010M5X11TR5.
This capacitor goes between the base and emitter of Q8008 P/N 2SC2229. NOTE:
the positive lead goes to the base of the transistor.I put mine in parallel
with th existing 0.047.

ALIGNMENT OF NEW CICUITRY

CM COUPLER

     1. Remove the ALC cable.
     2. Remove P06 (J04) on the Auto Tuner Relay Unit
     3. Key the driving radio in CW (FT-757, FT-767, etc)
     4. Adjust the power output to 400 watts
     5. Connect the Black lead of DC Voltmeter to pin 1 and the Red lead
to pin 3 on the Protector Unit, OR connect the Black lead to ground
and the Red lead to TP01 on the CPU Unit (use the 0.25V range on         the
DC voltmeter)
     6. Adjust TC5001 for a MINIMUM reading on the DC voltmeter
    7. After adjustment, reconnect P06 and the ALC cable

PROTECTOR UNIT
ALC METER AND ALC PROTECTOR ADJUSTMENT
     1. Set the ALC pot fully clockwise (CW)
     2. Apply +9VDC to TP7001
     3. Adjust VR7008 to the right edge of the ALC zone
     4. Set the ALC pot fully counter clockwise (CCW)
     5. No adjustment on the SWR Protector VR7004 is required.

IC PROTECT ADJUSTMENT
     1. Connect the DC voltmeter to the center of VR7004
     2. Adjust VR7004 to 3.8VDC +/-0.1V

The correct resistor and capacitor are available from Yaesu if you desire.
 TB-9601- Yaesu (562)404-2700