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Add a Digital Display to an Old Communications Receiver

One of the shortcomings of using an older communications gear is the fact that the analog dial isn’t very accurate. You’re always guessing at the frequency you’re receiving. In the AM or FM bands, this generally isn’t a problem because you usually know the frequencies of the local stations you’re receiving. On shortwave or for AM DXing, you need to know the exact frequency you’re on. I obtained this Realistic DX-160 recently for a good price and it was working well for a radio that was manufactured between 1975 and 1980. When it was new it sold for around $150.00. This radio was extremely popular in it’s day and continues to have a following even now. In the mid 70’s even the top receivers didn’t have digital displays as the circuitry of a frequency counter was more complex and bulky as the radio itself. Today we are lucky, we can buy a complete digital display for $10.00 that can be added easily to a radio. In this Instructable I will show you how I added a digital display to the DX-160 and programmed it to give the right frequency the radio is tuned to.

Note: A display can be added to any radio as long as you can access the signal from the IF oscillator which will be where it’s injected into the mixer. In a solid state receiver, the signal will probably be small enough to go directly into the frequency counter module (200 mV to 2 volts peak to peak). If you want to add a display to an old tube receiver, realize that the IF voltage will be much higher than this and a resistor attenuator network will be needed to reduce the voltage.

Supplies:
1) (1) Small project box (ebay or electronic parts store)
2) (2) digital display unit 1-1000 mHz. (This is what I used, but 1-100 mHz is perfectly acceptable) (ebay)
3) (1) 4700 microfarad electrolytic capacitor (ebay or parts store)
4) (1) 1N4007 silicon diode (ebay or parts store
5) (1) 15 nF capacitor (ebay or parts store)
6) Different colors of stranded hookup wire. (ebay or parts store)
7) (1) Alligator clip (ebay or parts store)
8) Electronic solder (hardware store)
9) Soldering iron (hardware store)
10) Hot melt glue and gun (hardware or craft store)
11) (2) pieces of Vector or Perf board (ebay or electronic parts store)
12) Electric drill (hardware or home improvement store)
13) Sharp knife (hardware store)
14) (6) small tie wraps (black) (craft store)
15) (6) large tie wraps (white) (craft store)
16) Long nosed pliers, (hardware or craft store)
17) Assorted screwdrivers (slot, phillips) (hardware store)
18) wire strippers (hardware store)
19) double sided tape (hardware store)”

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