Radio System Blog http://hamradiomaker.com/index.php/radio-system-blog Fri, 09 May 2025 10:15:27 +0000 Joomla! - Open Source Content Management en-gb Schematic of Step Attenuator http://hamradiomaker.com/index.php/radio-system-blog/90-schematic-of-step-attenuator http://hamradiomaker.com/index.php/radio-system-blog/90-schematic-of-step-attenuator Searched online to find some schematics of step attenuators and then edited schematic into QUCS.

Simulator result

DB

Volts Expected DB Calc DB
5    
4.46 1 -0.99
3.55 3 -2.97
2.52 6 -5.95
1.26 12 -11.97
0.403 22 -21.87
0.0675 42 -37.39

The +20 db step is off quite a bit.

]]> Radio System Sun, 14 Apr 2019 21:46:34 +0000 Make a Programming Cable for a Yaesu FT-4X http://hamradiomaker.com/index.php/radio-system-blog/89-make-a-programming-cable-for-a-yaesu-ft-4x http://hamradiomaker.com/index.php/radio-system-blog/89-make-a-programming-cable-for-a-yaesu-ft-4x I referenced this video to modify a Baofeng cable to make a programming cable for a Yaesu FT-4X.

 

  • Pulled 3.5 mm audio pin out of cable

 

Pulled out 3.5mm pin

 

  • Open case at USB end of the cable gently with small screwdriver. Pry at the cable stress relief end.
  • Watch this video (Yaesu FT-4X Programming Cable) and dig out the needed diode from your parts stock.

  • solder it up

 

Soldered Diode between TX and RX. Anode goes to TX.
 
 
 
Soldered diode between TX/RX (anode to TX)

 

  • Test the cable with programming software available at yaesu.com
  • Reassemble the case
]]> Radio System Sun, 14 Apr 2019 20:44:59 +0000