What is the headphone impedance
If you simply use an ohmeter you would find that the DC resistance is about 100 ohms. A proper measurement using a HP 204C Signal Generator and a HP 3400A Voltmeter showed an impedance of 123 ohms from 300 Hz to 4 kHz. This makes sense since the Working Instructions for the Telephones,
Loudspeaking No. 2 (Canadian) states:
"On Telephones Loudspeaking No 2 (Canadian) loudspeakers are two binding posts marked No. 19 Set.
They are connected to loudspeaker through a winding of 30 ohms (approx.) impedance. This impedance
approximately matches the output impedance of I/C amplifier of No. 19 Set."
The I/C amplifier would have to be cable of driving multiple headphones without significant loading effects.
How and from where I can get accessories for my WS-19
889 visitor(s) thought this was helpful. Do you?
Check the QM Stores area of The Wireless Set No. 19 Group website. Accessories are often advertised there, for sale or trade, and you also have the option of posting a "Want" for a specific item.
916 visitor(s) thought this was helpful. Do you?