Ham Radio Maker

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.

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

BITX20@groups.io Feed

Feed not found.
 

Buy RF Front End Board Kit for EU1KY Antenna Analyzer


David Richards Blog

Dave Richards AA7EE

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    Before building Jim W4LF’s Hobbydyne™ crystal set, I put together an impedance matchbox, for matching the detector diode to a variety of different headsets and earphones, so that I could determine the best ones to use. The world of serious crystal set listening was new to me, so I did some reading up. To give […]

Frequency VFO synthesizer Microb v.4

Frequency synthesizer Microb v.4 (Microb v.4S)

This looks pretty awesome. Might have to get one.

Manhatten Construction si5351 VFO by AA7EE

si5351 VFO by AA7EE

This si5351 Manhatten style constructed VFO is really slick

uBitx v5 Un-boxing