LINEAR AMPLIFIER SOFT START+DELAY YAESU ICOM DRAKE KENWOOD HEATHKIT COLLINS

Description

Double function board developed specifically for linear amplifiers. Required input voltage is * just * 100-240 Volts. Power is applied to the amplifier via a set of NTC resistors (negative temperature coefficient) of 20 ohms 6A. After a t1=400 mSeconds delay the NTCs are shorted applying full voltage to the amplifier. This allows the power supply capacitors to gradually charge without a massive current pulse applied to the line, amplifier power switches etc.
A second relay then kicks in after t2=3 minutes which controls a NC-C-NO dry contact that is used to disable the keying line (vox line) so the amplifier cannot be keyed the first three minutes protecting the life of the tubes. Because the terminal allows a NC-C-NO connection it covers every possible way to disable the vox line. Note that the writing on the board (NC-C-NO) is AFTER t2 has expired. I.e the NC contact closes only after t2. This board saves a lot of space and $ because it has both functions built in. Also most of the soft start boards out there requires a secondary voltage like a filament or DC control voltage. This board does not. Maximum current is 20A. If you want a different t1/t2 delay(s) let me know before buying and for an additional I will reprogram the controller to your needs. Input/output power is via 1/4" solderless crimping terminals. I can supply 5 blue insulated terminals for an additional .
Note :  do NOT mount this board in the RF area of the amplifier (spurious rf may crash the software). Board size is 3.1" x 2.5" about 1.2" high.
This is a new tested board and as with all electronics no returns. Look at my feedback and bid with confidence.