Original Item: Only One Available. According to the 1962 and 1963 annual reports of the Office of Civil Defense (OCD), the CD V-777-1 set, first produced in 1962, was intended for use in public fallout shelters.  By 1978, when Radiological Defense Preparedness (CPG 2-6.1) was published, that job had been given to the CD V-777-2 set, and the CD V-777-1 was now an "alternate set for emergency service organization use."  The older boxes (with the word "kit" on them) were produced when the CD V-777-1 served its original role as the primary set employed in fallout shelters. The box above right (with the word "set" on it) was produced later when the CD V-777-1 became the alternate set for use by emergency service personnel.

Quoting CPG 1-30 (FEMA 1981): "The CDV-777-1, alternate set, is the same as the CDV-777 except that it has only one CDV-715, high range radiological survey instrument. These sets are used for self-protection monitoring by emergency services, vital facilities and essential industries. The CDV-777-1, alternate set, is issued when more than one set is needed at a location and for use on emergency service vehicles (police, fire, rescue, ambulances, etc.)."  

Similarly, the 1991 FEMA publication Use of Civil Defense Radiological Instruments for Peacetime Radiological Emergencies (CPG 2-2), describes the CD V-777-1 set as "an alternate set for use by emergency service organizations."  In other words, the CD V-777-1 is an alternative to the CD V-777 set which was the standard set recommended for use by emergency service organizations.


With regard to the contents of the set, the 1991 FEMA publication CPG 2-2, Use of Civil Defense Radiological Instruments for Peacetime Radiological Emergencies, indicates that the recommended composition of the CD V-777-1   set is: one CD V-700 GM detector, one CD V-715 ion chamber, six CD V-742 pocket dosimeters and one CD V-750 charger-reader.  

The original makeup of the set as described in the 1963 annual report of the OCD was exactly the same except that it had two dosimeters, not six. The Defense Civil Preparedness Agency's Radiological Defense Preparedness pointed out that instrument sets issued after 1978 included six dosimeters.

The following text from CPG 1-30 Guide for the Design and Development of a Local Radiological Defense Support System (1981) nicely summarizes the capability that the CD V-777-1 set should provide emergency services self-protection monitoring:

"Self-Protection Radiological Monitoring Capability - for monitoring and assessing the radiological environment in order to control the radiation exposure of personnel who must conduct emergency operations in a fallout radiation environment. This capability is required for personnel in emergency services organizations; at vital facilities, including hospitals, utilities, and essential industries; and for the large number of additional emergency workers who would be required for postattack recovery operations. It is necessary to:

  - Evaluate the radiation risks of proposed operations

  - Maintain individual exposure records of emergency workers

  - Measure actual exposure rates at the location where emergency operations are being conducted to confirm or revise estimates

  - Evaluate how long personnel can work without exceeding established exposure limits

  - Measure the actual radiation exposures of personnel performing emergency operations"

One of the primary components of the kit is a complete excellent condition Lionel CD V-700 Model 6b Geiger Counter which was used for measuring radiation, primarily in case of a massive nuclear attack on the United States or other NATO countries. The CD V-700 is a very sensitive Gamma and Beta radiation detector, so sensitive that they were considered ‘useless’ in case of a thermonuclear war. This is good for modern day experiments, disasters and ‘treasure hunting’ with a Geiger counter.

This example is marked for the U.S. Civil Defense and comes complete. It was last calibrated in 1993, but dates to the 1960s. It is in overall excellent condition. Technical information can be found on the Civil Defense website at this link.

Watch a CD V-700 being tested:

This is one of the classic Geiger counters you’re likely to see in older movies and it may bring back some memories to people who lived in the unsure nuclear ages. Even now can be uncertain times with the amount of nuclear energy and power we use in the world and with countries working every day to build a nuclear arsenal for themselves so they can improve their ‘street cred’ in international politics.

The CDV-700 is very simple to operate and has just a few major components. The primary sensing component is the Geiger-Muller tube. The Geiger-Muller tube or GM tube was originally created by Hans Geiger and then further improved with the assistance of Walther Muller ( Müller ). The operation of the Geiger tube is basic in principal. It is a vacuum tube with an electrode in the middle and an outer shell with a charge (voltage) differential between the shell and the electrode. When a radioactive particle passes through the vacuum between the outer shell and the electrode it creates a conductive path.

The Geiger-Muller tube is contained inside of a steel housing and the steel housing has slots in it. If you rotate the outer housing of the steel housing 3 windows are opened removing shielding from the tube itself. With the windows closed the CD V-700 is sensitive to Gamma radiation. When the housing is rotated it will also pick up Beta radiation. The CD V-700 Model 6b is not capable of detecting alpha radiation.  Alpha radiation detector’s Geiger-Muller tubes usually have a window made from a material, normally Mica.

Inside of a Geiger Counter is a circuit which detects the conduction of electrical potential between the shell and the electrode and generates a click. In newer systems the pulse is fed into a pulse counting system which do the math and show the exposure on a digital display. In older systems like CDV-700 Model 6b Geiger counter the output pulse is tied to an analog averaging circuit which in it’s most simple concept is a capacitor which is charged by the pulse, and a resistor which provides the time base for decay. As a pulse charges the capacitor the stored energy in the capacitor increases, which also increases the reading the meters needle. The resistor slowly drains the capacitor causing the needle to drop back down. If multiple nuclear particles pass through the Geiger-Muller tube, then multiple charging pulses are applied to the averaging circuit, increasing the voltage on the capacitor and the needle reading as well. I’ve read that the Lionel Geiger detector has one of the best versions of the CDV-700 electronics as compared with Victoreen and other brands, yet others dispute that.

The schematic for the Geiger counter is included in the base of the housing for repair and maintenance of the device.

The electronics are implemented in the CD V-600 Geiger Counter with the easily accessible schematics and easy access to the batteries and the circuit board itself. Many of these Cold War era Geiger counters were designed with maintenance and serviceability in mind and you can tell. More modern Geiger counters do not contain any ‘user serviceable’ parts inside of them, but they are much smaller and more portable Geiger counters which fit in with today’s modern and compact lifestyles.


One extra note about the CD V-700 Model 6b is that it comes with its own radioactive check source with taped to the side of the Geiger counter which allows you to check the functionality of the counter to make sure the electronics are working okay. The radioactive check source is a small piece of either Radium 266 or depleted Uranium. The half-life of some of these materials is short compared to the physical age of these older detectors so they may provide you with a quality check of functionality.