N3ZI Kits - NEW Digital Dial / Frequency Counter

Update Aug 2018: Complete 80Mhz KITs now shipping, Limited Quantity


My Digital Dial is principally meant to be an inexpensive way to add a digital operating frequency display to homebrew radios such as the BITX-20, ARRL Homebrew challenge radios from KD1JV and N3ZI, 40-40 from the New England QRP club, SW+ from small wonder labs, the popcorn superhet, MMR40 and BITX20A from Hendricks QRPkits, and many others. It can also be useful with vintage analog/tube multi band radios.  A programmable IF offset allows the counter to measure the VFO frequency but display the actual operating frequency. It can also be used as a general purpose frequency counter.



The above photo shows the kit built omitting the prescaler for operation to 8Mhz

The above photo shows the kit built configured for HF, fast update
See manual for other configurations

Complete 80 Mhz Kits available, limited Quantity
(Kiss Electronics has shipped me their remaining PCBs)
Sold with ($26.50) or without LCD ($19.99)
(Works with many different LCD types being sold on ebay for $2 or so)
Click here for Manual
NO SMT Components, all parts are conventional through hole
Shipped with M74HC163(S/T) prescaler good to 80Mhz
LCD included 16x2, 16 pin, no color choice

Features and specifications
  • Programmable IF frequency, and VFO mode (VFO+IF, VFO-IF, IF-VFO)
  • Supports up to 9 different IF offsets
  • S/W Programmable to accommodate /n prescaler (n can be 2,4,8,16)
  • On board voltage regulator allows normal operation from 10 to 18VDC power source.
    • Battery operation possible by bypassing on board regulator, ~3mA at 3-5 VDC
  • 2 pushbuttons required only for programming IF and Setup
  • All programmable options stored in non volatile EEPROM, so they only have to be set once.
  • Input Sensitivity(HF): 150mV RMS see chart.
  • uCode, includes anti jitter s/w which prevents LSD from jittering between two values.
  • Measures VFO frequency up to 80 Mhz
  • 32 bit internal math
  • 100 Hz or 10 Hz display resolution.
  • No XTAL trim cap required, correction applied in S/W.
  • Update rate approx. 20 ms w/o prescaler. 80 ms with /4 prescaler.
  • NO Surface mount components
  • Supports many different inexpensive 44780 LCDs
    • Directly mounts with 16 pin version
    • On board driver for LED backlight
      • Up to 20mA when using the 78L05 regulator in a TO92 package
      • Up to 100mA when using the 7805 in a TO220 package, no heatsink
      • Up to 250mA when using the 7805 in a TO220 package, with heatsink
  • Read reviews on EHAM

PCB Dimension are approx 3.1 in x 1.4 inches, which is about the same as most 16x2 displays.


Schematic Diagram



Right Click, then View Image for larger image

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