cubic  The K9GDT Cubic Mini-Museum  k9gdt
 About Cubic Radios

     cubic     Cubic Corporation had a presence in the Amateur Radio arena for a few years in the late 1970's and early 1980's.  To the best of my knowledge, only four models were ever marketed by Cubic Corp.

While each model has a unique feature set, they share the following attributes:

  • IF frequency of 9 MHz
  • Single conversion hetrodyne type transmitter/receiver sections with LO premixing
  • High quality 8 pole crystal IF filter suitable for SSB
  • Excellent receiver performance in the presence of strong in-band signals. If you hear it, it's really there!
  • A reasonably decent implementation of audio derived AGC
  • Transmitter output of 100 watts PEP on all bands
  • Highly effective noise blanker
 The Models  (Click an image for more information)

Swan 100MX Astro 150A/151  Astro 102BX Astro 103
swan 100mx astro 150a astro 102bx
astro 103

Cubic's Unique Passband Tuning (102BX & 103)

Not all passband tuners are created equal. A traditional PBT (a.k.a. IF shift) moves a receiver's IF frequency away from interference, placing the QRM down the filter's response curve. However, there is one undesirable side-effect. The IF shift also moves the opposite filter skirt toward an adjacent frequency that may be occupied.

What if it were possible to move only one filter skirt? That's exactly what Cubic accomplished with their innovative PBT system! While the response of the 13.8MHz filter will be shifted toward another frequency, there will be nothing there to hear, thanks to the 9MHz IF filter. Cubic had this costly feature years before other radio manufacturers.

One big plus! These radios feature 16 poles of IF selectivity. This superb adjacent channel QRM rejection rivals modern DSP IF performance.

Cubic included a convenient LED "bar graph" just below the frequency readout to indicate the current passband setting.

One question comes to mind when studying the block diagram. Are the 102BX and 103 receivers single or triple conversion? Cubic's literature calls them single conversion radios.

     passband tuner

Resources      October 27, 2016  (Thanks to W6CAW for the update!)
Brock Publications
PO Box 5004
Oceanside, CA 92052
TEL: (760) 757-0372

Jim Singleton Publications
4044 Highway 101
Florence, OR 97439
TEL: (541) 999 2609
e-mail: WA5BDR

Cubic's service documentation was second to none.  If you need an owner's or service manual for your transceiver, contact Jim Singleton. He may even have NOS literature.

 Related Links    (Opens In A New Window)

 Return to Radio Page
 Return to George's Place
    October 27, 2016
  hit counter    Visits to this page since January 14, 2016

 ☚  Let's talk about Cubic Radios!