Hardware Side of JT65-HF. Required Hardware: HF SSB Transceiver Computer 2-6 Customs Cables Digital Interface (may not be required)

Hardware Side of JT65-HF

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

HFTransceiver

Computer DigitalInterface

JT65 Hardware Interconnects

HFTransceiver

Computer

“Mic”

“Headphones”

Speaker

“Mic”

JT65 Hardware Interconnects – Simplest

Digital Interface(Not Required)

VOX

PTT

Only 2 signal paths involved

HFTransceiver

Computer

“Mic”

“Headphones”

Serial Port

Speaker

“Mic”

JT65 Hardware Interconnects – Simple

5 PTT Gnd

7 PTT

Digital InterfacePTT Gnd

PTT

9 Pin RS 232Connectors

Only 3 signal paths involved

Only required to generate PTT signal

RTS

GND

Digital Interface - Simplest

5 PTT Gnd

7 PTT2.2 K

9 Pin RS 232Connector

PTT Gnd

PTT

NPNtransistor

Diodes = any working diode

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

HFTransceiver

Computer

“Mic”

“Headphones”

Speaker

“Mic”

Digital Interface

USB 2.0 to RS232 Converter•Mfg: eforcity•Model: PCABUSBX0049•Driver Download: http://driverdownload168.com

9 Pin RS 232Connectors

FM“USB” Port

Digital Interconnects Using A USB Port

PTT Gnd

PTT

HFTransceiver

Computer DigitalInterface

FM

“Mic”

“Headphones”

“USB” Port

F M

F MReceiver

AudioOut

FM

“Mic”F M

Digital Interconnects – Best

Ground Loops

HFTransceiver

Computer

120 VACOutlet

V2 mVACV1 mVAC

“Mic”Mic

Ground Loops

HFTransceiver

Computer

“Mic”Mic

V5 mVAC

V4 mVACV3 mVAC

120 VACOutlet

Ground Loops

HFTransceiver

Computer

“Mic”Mic

V5 mVAC

V4 mVACV3 mVAC

120 VACOutlet

Note: All voltages are 60 Hz AC

Ground Loops

HFTransceiver

Computer

“Mic”

Tone

V5 mVAC

V4 mVACV3 mVAC

120 VACOutlet

Ground Loops

HFTransceiver

“Mic”

Tone

V5

V4 mVAC

120 VACOutlet

Ground Loops

HFTransceiver

“Mic”

Tone

V5

V4 mVAC

120 VACOutlet

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

Ground Loops

HFTransceiver

Laptop

V2 mVAC

“Mic”

0 mVAC

Tone

120 VACOutlet

Ground Loops

HFTransceiver

Computer

“Mic”

V5 = V2 – V1

Tone

X X

V2 mVACV1 mVAC

120 VACOutlet

Ground Loops

HFTransceiver

Computer

“Mic”

Tone Isolator

V2 mVACV1 mVAC

120 VACOutlet

Ground Loops

HFTransceiver

Computer

“Mic”

Tone Isolator

V2 mVACV1 mVAC

120 VACOutlet

Several types of isolators: • DC signals• Audio signals• RF signals

9 PinRS 232

Connector*

5 PTT Gnd

F

7 PTT

+8 VDCfor Mic

100 uF

1 K

•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

To Mic Input*

Digital Interface

IsoPTT

+10 K

50

Optocoupler4N33

FromReceiverAudio*

IsolationTransformer

IsolationTransformer

FromComputer

“Headphones”M

MTo

Computer“Mic”

From USB 2.0to RS232

Converter

1 5

42

FPTT 5

PTT GND 6

MIC GND 7

MIC 1

M

FerriteChoke*

1 K* LED*

SHLDBRN

WHT

BLU

RED

1 K*

Optocoupler

Optocoupler

1 5

42

Turn-On time <5 usecTurn-OFF time < 100 usec