Chisholm Model B

Chisholm Industries Limited  Model B Radiophone
British Columbia, Canada Forest Service  Radio Serial Number ( unreadable)

When I received this unit it came without a wooden case, microphone or battery cables.  It did come with a name plate showing the top chassis layout which was a bonus. 

There are two two pin sockets mounted on the chassis which are identified as Rec and Trans. A variant of this radio a Humble Radiophone Model P12F had these same sockets on the chassis, without anything connected to them, Both the speaker and microphone were hard wired to the unit so it would only be a guess to know what they were specifically for.

Dimensions: 
Metal Chassis:   Including Knobs         W: 7.625 " X H: 5.25" X D: 5.5" 
                                                             Weight   5.25  lbs

Frequency Range: 2952 to 3445 kc Crystal Controlled

Tubes: 
Transmitter:  3V4 3V4 3V4 3A4
Receiver:      1T4 1R5 1T4 1U5 3A4 3A5
                                           
Power Requirements:
Power for the entire Radiophone is supplied from dry batteries. There are two groups of "A" and "B" Batteries which are described as "Normal Duty Batteries" and "Light weight batteries".  Two cables are provided, one for the normal-duty and one for the light weight batteries. Either set of batteries may be connected to the Radiophone by plugging the cable into the cable socket on the front of the radio. The later model variant’s of this radio have the battery cable(s) directly wired into the chassis.

Batteries:
Normal Use;
Quantity:  Voltage:       Use:            Mfg:            Type: 
   8              3                A                General       #6  Ignition Cells                                          
   4             45               B                General        V-30-B

Lightweight (Portable)
   1              3                   A            General        4H2
   4             45                  B            General        P-96-AA

Credits: 
Geoff Fors
Jerry Proc

Vous pourrez trouver sous ce lien 8 modèles d'appareils, 7 avec des images et 1 avec des schémas.
Tous les appareils de Vancouver Radio or Chisholm Industries; Vancouver