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Digital Racal Dana Frequency Counter

10MHz Reference OCXO Upgrade Module


High Stability 10MHz OCXO Upgrade for Racal Dana 19xx Series Frequency Counters and Timers

A high performance OCXO upgrade module to be used with the counter/timers originally fitted with the "Opt 04C" unovened crystal or "Opt 04T" TCXO 10MHz references.

Compatible with the following Frequency Counters.
  • Racal Dana 1991 Universal Counter
  • Racal Dana 1992 Universal Counter
  • Racal Dana 1998 Frequency Counter
  • Racal Dana 1999 Frequency Counter

Many of these Counter/Timers were originally fitted with a basic 10 MHz Crystal Reference PCB or the Opt 04T Temperature Compensated Crystal module. These gave frequency accuracies of just 10E-6 or 1E-6 respectively.

Our OCXO Upgrade PCB has a small OCXO module giving at least 2 orders of magnitude improvement on these original boards giving a stability of better than 1E-8.


Temperature Stability: 0 to 70 degrees C is better then 1E-8  (3 orders of magnitude better than the 04C option)

Ageing: 5E-10 per day, 1E7 per year.

You can check our website here where we detail our project to make these OCXO modules here.

Fitting instructions:

Fitting is easy and takes 5 minutes and you just need a small Posi-Drive/Philips screwdriver.

  • Unplug the counter from its supply
  • Remove the rear bezel (2 screws) noting which way up it was orientated as it only fits back on one way.
  • Slide off the case
  • The original reference PCB is mounted by a single screw and into a 5 pin header on the PCB. See photos. Remove the screw and the original PCB taking care not to lose the screw and washer.
  • Mount the new PCB into the counter as shown in the photos and secure with the screw. The rear mounted adjustment trimmer need to point towards the back panel
    Take care to make sure you have aligned all the pins on the main board with the socket on the new oscillator PCB
  • Reassemble the case and rear bezel.

The oscillator PCBs are soak tested for 24 hours then aligned against our GNSS Disciplined 10MHz reference before shipping. If you need to adjust/trim further with a local 10MHz source you trust, the adjustment pot is accessible from the rear panel.

The OCXO PCBs come with a 12 month warranty against failure.

Racal Dana OXCO $50 Plus Shipping


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AllStar Link USB Sound Card

CM108B AllStar Link Node Sound Card Interface compatible with HamVoip.

This compact USB Audio interface will plug into a PC or Raspberry Pi running the HamVoip software so that you can build your own Allstar Node Link. The bespoke USB Sound card is built into the USB shell and uses the CM108B audio codec. It is not a modified cheap Chinese board from eBay.

Key Features

  • Built-in C-Media CM108B USB Audio codec. Fully supported as a USB audio device in HamVoip including GPIO for PTT and COS.
  • The interface is designed to deal with expected audio levels from radio data ports for Tx/Rx.
  • CM108B GPIO VOL DN supported for COS to connect to radio SQL line.
  • CM108B GPIO3 PTT supported by built-in buffer/driver.

The C-Media CM108B codec is fully supported in HamVoip as a USB audio device. Tx and Rx audio levels are suitable for direct connection to modern transceiver data ports. The CM108B  "GPIO3" signal is used for PTT keying and the "VOL DN" input for COS (Carrier operated squelch). These particular GPIO signals are expected in the Hamvoip Simple USB Audio Tune settings

HamVoip Simple USB settings for this interface

For the PTT, set the Ham Voip simple-usb-tune-menu option "I" set to "active low".
For  COS (Carrier operated Squelch)  setting the Ham Voip simple-usb-tune-menu option "J" to "usb" works on for example Yaesu Radios.

Cable length from USB to connector is 10cm so perfect if you are installing inside a case with a Raspberry Pi.

Radio Connection

You can choose to have the interface shipped with a pre-wired DB9 Female, Standard wired 6 pin Mini-Din (Yaesu, Icom, Kenwood)  or we can provice it with tinned wire ready for you to add your own plug.

Option 1 - DB9 Plug - 10cm cable - (ask if you need longer)

Pin 1 - Rx audio from the radio to the USB interface.
Pin 2 - PTT signal. Pulls low for PTT keying. (Ham Voip simple-usb-tune-menu option "I" set to "active low")
Pin 3 - COS Signal. Configuration depends on your radio. For Yaesu, COS set to "usb" works. Your radio may need "usbinvert"
Pin 4 - Tx audio from interface to the radio.
Pin 5 - Ground (0v)

Option 2 - Bare wiring so you can add your own plug - 10cm cable (ask if you need longer)

Black - Tx audio from interface to the radio
Yellow - Rx audio from radio to the interface
White - PTT signal.
Red - COS signal
Screen is ground/0v

Option 3 - 6 Pin Mini-Din Plug with 1.5m cable

This option is perfect if you are utilising an old VHF/UHF mobile radio to use for a Node. Many Yaesu and Icom dual band radios have a standard wired 6 Pin Mini-Din data/packet socket on the rear panel 

Pin 1 - Tx audio to the radio
Pin 2 - Ground
Pin 3 - PTT
Pin 4- Not Used
Pin 5 - Rx Audio from the radio
Pin 6 - Squelch line from the radio

AllStar Link USB Sound Card  From $40.00

Cable termination options

Add Tracked Shipping

Standard shipping is $10. If you wish to upgrade to tracked shipping on your item then you can choose to add it to your Shopping Cart here. You just need to add it once and the cost is $5. If you are in the USA, do not add this option. We already use a tracked USPS shipment to The USA.