Yaesu Model FL-2100B RF Linear Amplifier

PLEASE NOTE:  Selling within the U.S.A., lower 48 States only.  No out-of-country sales will be accepted due to shipping complexities.

This Yaesu Model FL-2100B was previously owned (single owner) and is in full working order and in good physical condition.  The amplifier has been maintained well over the years and has had the original 572B tubes replaced this past year, along with the plate cap connection parasitic suppressors.  

Yaesu seems to have originally designed this amplifier to function with the Cetron brand of 572B tubes.  The original Cetron 572B tubes in the amplifier were still functional but had reduced power output.  For this reason, new tubes were installed this past year.  The Centron brand of 572B tubes is no longer available.  Therefore, a matched set of Taylor 572B tubes was purchased from RF Parts Company.  The Taylor tubes have functioned well, with no noticeable difference in the operation of the amplifier, other than the output power level is now back up to what it used to be. No changes to the amplifier circuitry or bias current level were needed for it to function with the new Taylor 572B tubes. This Yaesu FL-2100B is essentially “stock” as it came from the factory with no user modification made to the amplifier.

(Just a brief note on tubes for the Yaesu FL-2100B.  Because of the lack of availability in the originally supplied Cetron tubes, Yaesu published a bulletin, File No. TB-9627, dated July 16, 1996, that the use of Svetlana (Russian) and Generic Chinese branded 572B tubes, when used in the FL-2100B have sometimes been found to “self-oscillate” with the amplifier in “standby” mode, causing considerable damage to the equipment. The bulletin proposed a change to the bias circuitry in the amplifier to increase the bias voltage on the grids of the 572B tubes and also a reduction in the bias current setting from 0.09 amp to 0.03 amp.  Supposedly, this change would allow the use of other brands of 572B tubes, which may differ from the characteristics of the originally used Cetron tubes.  I did purchase the Bias Modification parts kit as a precaution, should I need it when the tubes were replaced, but I did not find it necessary to install.  I will provide this Bias Mode kit with the sale of this amplifier should the new owner need it at some later date.)

Yaesu Model FL-2100B Specifications

 - Circuit:                      Grounded Grid Class B

 - Freq. Coverage:        Ham Bands 80, 40, 20, 15, 10 Meters

 - Plate Input:                1200 Watts PEP, 1000 Watts CW, 600 Watts AM

 - Plate Voltage:             2400 Volts DC

 - Drive Required:          100 Watts PEP

 - Input Impedance:        50 ohms, unbalanced

 - Output Impedance:      50 - 75 ohms, unbalanced

 - 3^rd Order Distortion:     30 db or better at 1000 Watts PEP

 - Tube Compliment:         2 x 572B / T160

 - Cooling:                         Forced-air Cooling

 - Power Required:            AC 100, 110, 117 Volts,50/60 Hz, 18 Amps

                                          AC 200,220, 234 Volts, 50/60 Hz, 9 Amps

 -Dimensions:                    13.5” Wide, 6" High, 11.5” Deep

 - Weight:                            41 lbs

CAUTIONS:

1   1.  EXCEEDING THE CURRENT LEVELS LISTED IN THE OPERATING MANUAL MAY CAUSE SPURRIOUS VIOLATIONS OF FCC RULE 97.13.  THIS AMPLIFIER IS SPECIFICALLY DESIGNED FOR USE WITHIN THE RADIO AMATEUR SERVICE.

2.     2.  THIS AMPLIFIER PRODUCES HIGH LEVELS OF VOLTAGE FOR ITS OPERATION.  CONTACT WITH VOLTAGES FOUND IN THIS AMPLIFIER CAN BE LETHAL.  ANY WORK TO BE PERFORMED WITHIN THIS AMPLIFIER SHOULD BE UNDERTAKEN BY KNOWLEDGEABLE AND EXPERIENCED PERSONNEL ONLY.  ALL BEST PRACTICE AND SAFETY PROCEDURES SHOULD BE FOLLOWED ANY TIME WHEN WORKING WITHIN THIS DEVICE.

3.     3.  DO NOT ATTEMPT TO REMOVE ANY EXTERIOR CASE OR INTERNAL COVERS WHILE THIS DEVICE IS POWERED ON OR STILL PLUGGED INTO A POWER SOURCE.  DO NOT DEFEAT THE OPERATION OF, DAMAGE, OR REMOVE ANY SAFETY INTERLOCKS.  (SEE CAUTION #2, ABOVE.)