EB5AGV's FT-102 Power Amplifier tuning
Keep them glowing for a long time!
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).
If you are interested in this transceiver, please, join us at the
Yaesu FT-102 Yahoogroup - Since 2001!