Bi-lateral Amplifiers and Filter Board
The circuit below shows the two bilateral amp stages and the 9.0 MHz crystal filter from the GQRP club whose impedance is 500 Ohms. A single winding coil of 19 turns tapped at the 6th turn will do the matching ( 19^2 = 361 and 6^2 = 36, 361/36 = 10. Thus 500 ohms is matched to 50 Ohms. If you use the INRAD Model #351 the in/out impedanec is 200 Ohms so you need a 4:1 match. A single winding of 20 turns tapped at 10 turns will give you a 4:1 match. (20^2 = 400 and 10^2 = 100. 400/100 = 4).
In the second drawing, the interconnections to the SBL-1 Double Balanced Mixers are shown. Keep in mind that the SBL-1's are 7 dBm devices which says the LO and BFO Peak to Peak signal should be no more that 1.414 Volts PTP. At the output/input side of the SBL-1 Product Detector/ Balanced Modulator I have included an audio filter so that only audio is passed into and out of that port (Pins 3&4 connected together.) The output level of the Si5351 can be set in software and I have had no problems running the bias level at 8 Ma. In another rig that uses the ADE-1L which are 3 dBM devices I have set the bias level at 2 Ma. More on this in the section on the Arduino.
The last photograph shows the actual hardware and the bi-lateral amps are a combination of leaded and SMD components. This circuit module works very well!