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The PK-4 SSR keyer kit - 10/05/2005


March 28, 2023: SSR option is now $7 due to parts price increases

January 2019: kit now includes a solder masked, silk screened circuit board

July 7, 2023 see the Keyer Enclosure Kit to house the keyer kit

05/21/2020: put a PK-4 demo video on Youtube .

12/23/2013: see the new SMT Keyer kit, PK-4 version

The PK-4 SSR is the latest in the PK series of keyer kits. It replaces the popular PK-4 kit but adds an optional Solid State Relay (SSR) 6 pin chip for tube keying, similar to the Keyer Accessory kit . The Solid State Relay is rated at +/- 120 mA and +/- 400 V. Some cathode keyed rigs such as the Knight T-150 may require the Keyall due to larger than 120 mA currents. If in doubt, measure the current and voltage with your rig. The PK-4 is fully pin compatible with the Norcal keyer. The PK-4 is pin compatible with the PK-3, PK-2 and PK-Basic (Tick and K8 chips, too) with the addition of a 10k ohm pullup resistor between pin 1 and 4 of the keyer chip socket. The PK-4 shares the pot speed control of the previous PK series and the Norcal keyer but it has a large number of new additional features. Here are a few highlights:

[PK-4 SSR board picture]

  • pot or paddle speed control, 5 to 50 WPM
  • two 80 character memories plus an 80 character callsign memory
  • OR optionally two 80 and two 40 character memories
  • memories & settings retained without power (EEPROM)
  • Ultimatic or Iambic A or B keying modes
  • beacon mode, variable delay, up to 60 seconds
  • adjustable element weighting
  • variable sidetone frequency
  • low standby power (about 7 ua at 5 V, with regulator)
  • small size (1 by 1.5 inches)
  • Kit price (no doc) is $18.00 + shipping/handling
  • Kit with optional SSR: price (no doc) is $25.00 + shipping/handling
  • PK-4 chip (no doc) is $5.00 + shipping/handling

    • (multiple purchases of the PK-4 chip (no doc), will be sent in a single anti-static bag)

    Printed manuals available for an additional charge or save money by downloading and printing your own copy of the manual , schematic and hookup diagram .
    Don't get sub menus ?? See the sub menu doc

    Print out a Kit order form to figure your order manually
    or try our: javascript order form to let your browser do the math!

    For larger quantity purchases, manual pricing or to combine with other items, just send an email to:

    with your question.

    Downloadable files for the PK-4 SSR

    The Acrobat files of complex diagrams (like the PK-4 schematic) may not view well on your computer screen - suggestion: use the magnifier to zoom in for better detail or print out the file.

    pk4ssr2.pdf (58k) - PK-4 SSR schematic

    pk4ssrh.pdf (54k) - PK-4 SSR manual in Acrobat format

    pk4hu2.pdf (32k) - PK-4 SSR Hookup diagram in Acrobat format

    pk4ssrl.jpg (69k) - PK-4 SSR larger picture

    pk4diag.txt (1k) - quick PK-4 resistance / voltage checks text file

    pk4ts.htm (1k) - PK-4 Troubleshooting guide

    pk4menus.pdf (11k) - a PK-4 menu "cheat sheet" by Chuck Carpenter, W5USJ (thanks, Chuck)

    stalkin.pdf (16k) - Stalking the Wild Multipress! - an Acrobat file of a hardware method to solve the problem of pressing 2 or 3 switches at the same time.

    modeab.pdf (8k) - an Acrobat file explaning the differences between Iambic mode A and B

    ultimat.txt (4k) - a text file on the Ultimatic mode

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