Modifications for the Yaesu FL-7000



19-07-1998 FL-7000 10 meter transmit mods

  1. Remove power and all other cables.
  2. Remove 4 screws from top cover.
  3. Remove top cover and right and left panels.
  4. Remove 4 screws from power combiner unit and remove screen plate.
  5. Locate switch so1 on the cpu unit and set to off position ( a small screwdriver can be used to reach switch)
  6. Reassemble unit.




22-08-1998 FL-7000 desensitize the protection circuitry

From: Howard Ryder [email protected]

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
POWER SUPPLY UNIT
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