Welcome - The PA0KLT Low Noise VFO Synthesized Kit

Updated 02 June 2014

PA0KLT V4.20 Firmware - with Optional RIT and Fast Tuning Functionality & Optical Encoder/Tuning Knob

PA0KLT and SDR-Kits are pleased to announce that all PA0KLT Kits ordered and shipped after1st August 2012 will be supplied with upgraded V4.20 firmware.

The V4.20 Firmware offers the following new Optional Functions:

  1. Optional RIT (Receive Incremental Tuning) - This is implemented via two new extra push-buttons.
    RIT is enabled by pressing the RIT, a second press on the RIT button disables the RIT offset. RIT is also disabled in TX
    /Lock Mode.
    A press on the 2nd button resets any RIT offset back to 0 kHz. The maximum RIT offset range is +/- 10 kHz/
    The extra hardware required for RIT Function is included in all PA0KLT Kits supplied after 1st August 2012.

  2. Optional Fast Tuning - The V4.20 firmware also supports Fast Tune as an option. Fast Tune is enabled via a suitable Encoder fitted with switch or
    by a separate pushbutton switch (Optional hardware required).
    When the switch is briefly pressed, this provides for a 25x Fast Tune rate, whilst a second press revert to the Normal Tuning as before.
    For example, with a 24 step encoder, enhanced by the firmware to 96 steps/turn and a 10 Hz tuning step selected this results in a resolution of 0.96 kHz
    per turn. When Fast Tune switch is enabled the resolution increased to 24 kHz per turn until Fast Tune is switched off again.

    PA0KLT V4.20 Connection Diagram for RIT and Fast Tune Options

Firmware Upgrades to V4.20 for older PA0KLT Kits – SDR-Kits is pleased to offer following upgrades PA0KLT Kits with older firmware:

A kit of parts is available in the WebShop to upgrade older PA0KLT Kits with V4.20 functionality: This kit contains a new Atmega168 chip as replacement,
2 pushbuttons, and a 2k2 resistor.

To implement Fast Tune, a 32 step Optical or a 24 step Mechanical Encoder with a built-in switch is necessary. Either is available in the WebShop.

Optical Encoder and Matching 44mm Tuning Control Knob announced

At request of many Customers, SDR-Kits are now stocking a quality 32 step Optical Encoder with built-in switch to replace the mechanical encoder in the PA0KLT Kit
together with a matching Tuning Control Knob. These parts are ideal as an upgrade for the PA0KLT VFO Kit in Receivers or Transceiver Projects.
The Optical Encoder and Tuning Knob provides for a professional feel, touch and look to any Quality Amateur Radio Project yet at modest cost.

PA0KLT Kit - Information

The PA0KLT Low noise VFO kit is available with various Si570 Chips which set the maximum frequency range required up to 1417 MHz (1.417 GHz)

Kit A supplied with Si570CAC and overs 3.45 - 210 MHz - output is CMOS Square wave
Kit B supplioed with Si570BBC - covers 3.45 - 280 MHz - output is LVDS Square wave
Kit C supplied with Si570BBB - cover 3.45 - 945 MHz - output is LVDS Square wave
Kit D supplied without chip -  If you already have a suitable Si570 chip.
Kit E supplied with Si570DBA - covers 3.45 - 1417 MHz - output is CML Square wave
Kit F supplied with Si571CFC - provision for AF input for FM Modulation - covers up to 210 MHz
with CMOS square wave output

Click here for Pricing and Ordering information shown below

New Updated V5.4 Kit Assembly manual published 29th November.  New Drawings by PA0KLT.  Please download!

Download PA0KLT Kit Assembly Manual V5.4 for new ISSUE 2 PCB for kits shipped after June 1st 2010

Download PA0KLT Kit Assembly Manual V4.4 or older ISSUE 1 PCB for kits shipped up to 31st May 2010

Datasheet for WBC4-1WLB transformer 2 MHz - 1000 MHz

Frequency coverage is from 3.45 MHz up to 1417 MHz, depending on the type of Si570
device fitted. The minimum tuning step is selectable from 1 Hz, 10Hz, 100 Hz, 1kHz

The design offers a Smooth Tuning experience like in a high quality Analogue VFO
There is no interference when the frequency of the Si570 is tuned within
+/- 3500 ppm from last Coarse Frequency command executed. Tuning
resolution is 96 steps for each turn of the tuning control knob.

Kit suitable for constructors with some previous kit assembly experience. Some components like capacitors (0805mm) and Si570 are Surface Mount Devices

Up to 32  frequencies may be stored in Memory in two banks (Memory A and Memory B)

Some Applications

Kit Contents:

Complete Kits will contain a quality double sided PCB, a programmed Atmel ATMEGA168, 6 pushbuttons, Mechanical
Rotary encoder without switch, all connectors - LCD display with backlight. Si570 chip will be supplied as ordered
(Si570 Chip not shown on photo)

PAOKLT Kit Pricing and Orders - see the WEBSHOP


Copyright notice: The PA0KLT project design on this page is copyright 2008 - 2014 by Ton Blokker PA0KLT and SDR-Kits
Assembly Manual and Kit of parts produced by - Website Copyright 2008 - 2014 by