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
Computer
Digital
Interface HF
Transceiver

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

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

6. Digital Interface - Simplest Diodes = any working diode
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
Computer HF
Transceiver
“Mic”
Speaker
“Headphones”
“Mic”
9 Pin RS 232
Connectors M F
PTT
“USB” Port
Digital Interface
PTT Gnd
USB 2.0 to RS232 Converter
Mfg: eforcity
Model: PCABUSBX0049
Driver Download:

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

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

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

12. Note: All voltages are 60 Hz AC
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 V5 mVAC V3 mVAC V4 mVAC 120 VAC
“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 Note: V5 will cause 60 Hz hum on transmit signalHF
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 Laptop Transceiver 0 mVAC V2 mVAC 120 VAC Outlet “Mic”
Tone
0 mVAC
V2 mVAC
120 VAC
Outlet

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

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

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

20. Digital Interface + +8 VDC for Mic 9 Pin RS 232 Connector* From To
Isolation
Transformer To
Computer
“Mic”
From
Receiver
Audio*
1 K* M M
+8 VDC
for Mic
Isolation
Transformer
10 K
100 uF
From
Computer
“Headphones” +
MIC 1 M 50
Ferrite
Choke*
RED
BLU
PTT 5
To Mic Input*
MIC GND 7 F
WHT
SHLD
PTT GND 6
BRN
1 K*
LED*
Iso
PTT
7 PTT
1 K
From USB 2.0
to RS232
Converter 1 5 F
Optocoupler
4N33 2 4
5 PTT Gnd
Transformers are Mouser P/N T
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 Turn-On time <5 usec1 5 2 4
Turn-On time <5 usec
Turn-OFF time < 100 usec