EB5AGV's FT-102 Power Amplifier tuning
Keep them glowing for a long time!
Yaesu FT-102
As most tubed power amplifiers (one exception is the Central Electronics CE-100V and CE-200V),
the FT-102 PA should be tuned to work. Here you have a brief guide to do this. I have extracted this
information from the User's Manual and has worked for me all right. I keep a copy of this information
just below the rig, for fast access when I switch from another transmitter (not all are the same!)
- Select the default values for the controls:
- MODE: TUNE
- LOADING: 0
- BAND: desired band
- PLATE: pre-select depending on band
- DRIVE: 0
- METER SELECT: Ic
- Connect POWER and HEATER and wait 1 minute
- Turn the RF AMP ON and find a peak in background noise with PRESELECT
- Activate PTT momentarily. Ic should be 75 to 80mA
- Press PTT. Set DRIVE to about 9 o'clock position. Adjust PRESELECT for a peak reading.
- The following steps should be maximum 5 seconds each:
- Activate PTT. Find an Ic DIP with PLATE control. Go back to reception.
- Press the PTT. Get an ALC indication of '9' with the DRIVE control. Return to reception.
- Put LOADING to '1'. Press PTT. Get an Ic DIP with PLATE. Go back to receiving mode.
- Advance the LOADING control slightly and re-DIP with PLATE until the Ic DIP is exactly at 300mA (350mA in 1.8MHz band).
The final LOADING position should be close to the table shown in manual (page 24).
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