Hardware Side of JT65-HF

1. Hardware Side of JT65-HF

2. Required Hardware: • HF SSB Transceiver • Computer • 2-6 Customs Cables • Digital Interface (may not be required)

3. JT65 Hardware Interconnects Digital Interface HF Transceiver Computer

4. JT65 Hardware Interconnects– Simplest Only 2 signal paths involved HF Transceiver Computer Speaker “Mic” “Headphones” “Mic” VOX PTT Digital Interface (Not Required)

5. JT65 Hardware Interconnects– Simple Only 3 signal paths involved HF Transceiver Computer Speaker “Mic” “Headphones” “Mic” 7 PTT PTT RTS Digital Interface Serial Port PTT Gnd GND 5 PTT Gnd 9 Pin RS 232 Connectors Only required to generate PTT signal

6. Digital Interface - Simplest NPN transistor 2.2 K 7 PTT PTT PTT Gnd 5 PTT Gnd 9 Pin RS 232 Connector Diodes = any working diode

7. POTENTIAL PROBLEMS: • Some computers do not have a “MIC” input • Tones generated by computer may not have equal amplitude • May be hard to identify this problem • May not be a common problem • No RS 232 serial port • Difficult to set MIC level to transmitter • Typical computer audio out is ~2V • Typical “MIC” input level is ~10mV • Difficult to set MIC level to computer • Don’t use JT65 software to adjust receiver audio level • Ground loops

8. Digital Interconnects Using A USB Port HF Transceiver Computer Speaker “Mic” M “Headphones” “Mic” 9 Pin RS 232 Connectors PTT Digital Interface “USB” Port PTT Gnd F • USB 2.0 to RS232 Converter • Mfg: eforcity • Model: PCABUSBX0049 • Driver Download: http://driverdownload168.com

9. Digital Interconnects – Best Digital Interface HF Transceiver Computer Receiver Audio Out “Mic” F M M M F M F M “Headphones” “Mic” F “USB” Port F

10. Ground Loops HF Transceiver Computer Mic “Mic” V1 mVAC V2 mVAC 120 VAC Outlet

11. Ground Loops HF Transceiver Computer Mic “Mic” V5 mVAC V3 mVAC V4 mVAC 120 VAC Outlet

12. Ground Loops Note: All voltages are 60 Hz AC HF Transceiver Computer Mic “Mic” V5 mVAC V3 mVAC V4 mVAC 120 VAC Outlet

13. Ground Loops HF Transceiver Computer “Mic” Tone V5 mVAC V3 mVAC V4 mVAC 120 VAC Outlet

14. Ground Loops HF Transceiver “Mic” Tone V5 V4 mVAC 120 VAC Outlet

15. Ground Loops HF Transceiver “Mic” Tone V5 • Note: • V5 will cause 60 Hz hum on transmit signal • V5 can also cause broadband noise on transmit signal • Typical microphone output level ~10 mV V4 mVAC 120 VAC Outlet

16. Ground Loops HF Transceiver Laptop “Mic” Tone 0 mVAC V2 mVAC 120 VAC Outlet

17. Ground Loops HF Transceiver Computer “Mic” Tone X X V5 = V2 – V1 V1 mVAC V2 mVAC 120 VAC Outlet

18. Ground Loops HF Transceiver Computer “Mic” Isolator Tone V1 mVAC V2 mVAC 120 VAC Outlet

19. Ground Loops HF Transceiver Computer “Mic” Isolator Tone • Several types of isolators: • DC signals • Audio signals • RF signals V1 mVAC V2 mVAC 120 VAC Outlet

20. Digital Interface Isolation Transformer From Receiver Audio* To Computer “Mic” 1 K* M M +8 VDC for Mic Isolation Transformer 10 K 100 uF From Computer “Headphones” + MIC 1 RED M 50 PTT 5 BLU To Mic Input* Ferrite Choke* F MIC GND 7 WHT PTT GND 6 SHLD BRN LED* 1 K* Iso PTT 1 K 7 PTT From USB 2.0 to RS232 Converter 5 1 Optocoupler 4N33 F 2 4 5 PTT Gnd • Transformers are Mouser P/N 546-149T • 600W CT/600W CT • 200 Hz to 15 KHz • 1 watt • *: Not included in some (ie, SCI-6) designs 9 Pin RS 232 Connector*

21. Optocoupler Optocoupler 5 1 2 4 Turn-On time <5 usec Turn-OFF time < 100 usec