- RE-TUNE the FL-2100B -

This is a description on HOW-TO Re tune the FL-2100B amplifier for best performance on 11-Meter band. If you use the upper portion of the band, on most cases re tuning is not needed,- if you however go down close to 26MHz retuning will give you a couple of extra watt output.

If you do not mind losing 10 meters on your FL2100B, this quick mod should have you up and running on low part of 11 meters with full power output.

- Preparation -
  1. Make sure that the amp has been UNPLUGED and that the PLATE VOLTAGE has dissipated before you proceed.
  2. Turn your FL2100B upside-down on a smoth surface. Remove the screws that hold the bottom cover on,- and remove the bottom cover of the amp.
  3. Place the FL2100B on its side with the transformer end down towards the smoth surface.
  4. Set the BANDSWITCH to : 10
  5. Set the PLATE CONTROL to : 9
  6. Set the LOADING CONTROL to: Fully counter-clockwise

Location of 'L206' - Close to the grounding wingnut.

Refere also to the 'INSTRUCTION MANUAL' (.pdf file)

- RE-TUNE Procedure -
  1. Disconnect the 850 volt red wire that leads from the transformer to the DIODE BOARD (located right behind the TRANS - OPERATE switch.
  2. Install a SWR bridge between the EXCITER and the FL2100B. Tune your HF rig to 27MHz (Or any other decided center frequency on the 11M Band)
  3. Turn the FL2100B on and place the amp in the OPERATE MODE. Excite the the AMP with an AM signal, enough so that you can calibrate (set) your SWR meter.
  4. Place your SWR meter in the REV position and read the SWR.
  5. While in the TX mode, tune L206 (located near the GROUNDING WINGNUT just inside of the amp chasis) untill you achive your lowest SWR reading. You have just completed the retuning proceedure of the 10 meter ANTENNA INPUT COIL.
- Finished! -
Re-solder the 850 volt red wire (with the AMP off and un-pluged).
Re-assemble the AMP and enjoy INCREASED POWER OUTPUT on 11 METERS.


*** End of page ***
<--Back