harbach-electronics sk-301 Manuel D’Utilisation

2

( )

Remove the small white wire from the center c ontact o f the “antenn a relay” jack.  Remove
the other end of this w ire from  the solder post near the coax connec tor.

( )

Route the BLUE wire from the SK-301 under the circuit board and connect to the center
contac t of the “anten na relay” jack and solder.  

( )

Connect the  YELLOW wire from the SK-301 circuit board to the solder post where the white
wire was removed and solder.  Note, there is a 39

Ω

 resistor also c onnec ted to this po st.

( )

Reinstall the left corner piece and rear panel onto the chassis.  Place the chassis back into
the case.

This completes the installation of the S K-301 “Soft Key” module.  You may not SEE any

difference in the  operation of your exciter or am plifier, but you will know that you have reduced the
stress on the exciter’s keying relay by many orders of magnitude.

Jeff Weinberg – W8CQ

468 County Road 620

Polk, OH  44866-9711

(419) 945-2359

R1

200K

Ω

 ½W  5%

R2

10K

Ω

 ¼W  5%

R3

2K

Ω

 ¼W  5%

C1

100

µ

F 10VDC

C2

0.1uF 50VDC

D1

1N4005 (1A 600 PIV)

D2

1N5817 SC HOT TKY (1A 20V)

D3

1N60 GERMANIUM

IC1

4N33 OPT OCO UPLER

Q1

IRF9610 HEXFET (P-CHANNEL)