Specification of headphones - UK Vintage Radio Repair and Restoration Discussion Forum

GMB · 1st Jul 2004, 2:16 pm

What values of impedance and sensitivity does one expect from "high impedance" headphones as used, for example, with early radios and military sets (e.g. R1116, R1155)?

paulsherwin · 1st Jul 2004, 3:19 pm

They're normally 2K. Sensitivity varies a lot, but if they've got to work with a crystal set they must be fairly sensitive

Best regards, Paul

AC/HL · 1st Jul 2004, 7:44 pm

Headphones for crystal sets do need to be high impedance, and sensitive as Paul says. Those for military radios (ie DLR5s) are normally low impedance (but high impedance will work OK). I don't know the R1116, but the R1155, like all similar vehicle/aircraft fit radios to this day, is designed to feed several sets of headphones via a system of "control boxes". The output will be typically 50-100mW, and the impedance from tens to the low hundreds of Ohms.

1st Jul 2004, 2:16 pm	#1
GMB Nonode Join Date: Aug 2003 Location: near Reading (and sometimes Torquay) Posts: 2,272	Specification of headphones What values of impedance and sensitivity does one expect from "high impedance" headphones as used, for example, with early radios and military sets (e.g. R1116, R1155)? Last edited by Station X; 27th Dec 2004 at 9:44 pm. Reason: Import

1st Jul 2004, 3:19 pm	#2
paulsherwin Moderator Join Date: Jun 2003 Location: Oxford, UK Posts: 18,655	Re: Specification of headphones They're normally 2K. Sensitivity varies a lot, but if they've got to work with a crystal set they must be fairly sensitive Best regards, Paul

1st Jul 2004, 7:44 pm	#3
AC/HL Moderator Join Date: Nov 2003 Location: Heckmondwike, West Yorkshire, UK. Posts: 7,632	Re: Specification of headphones Headphones for crystal sets do need to be high impedance, and sensitive as Paul says. Those for military radios (ie DLR5s) are normally low impedance (but high impedance will work OK). I don't know the R1116, but the R1155, like all similar vehicle/aircraft fit radios to this day, is designed to feed several sets of headphones via a system of "control boxes". The output will be typically 50-100mW, and the impedance from tens to the low hundreds of Ohms. __________________ Bill, BVWS member Last edited by Station X; 27th Dec 2004 at 9:45 pm.