This Shure Slim-X 777 Crystal Microphone, was made for Voice or Music. It is Small & Perfect for a hand held Harmonica Microphone.
I have tested this one with a guitar amplifier and it sounds great with a lot of drive.
It comes with a 7 foot cord with Connectors.
Frequency Response: 60 to 10,000 Hertz.
Polar Pattern : Omnidirectional.
Impedance: High (Recommended load impedance 1 to 5 megohms)
Voltage Sensitivity: 1.05 millivolt r.m.s. per microbar at end of 7 foot (2.1 m)
cable across 1 to 5 megohms at 1,000 Hertz (this is equivalent to 59.5 db below one
volt per microbar). E.I.A. Microphone Rating Gm (Sensitivity) -162.0 db.
Cable: Detachable 7 foot (2.1 m) rubber-covered, single-conductor, shielded cable
with Amphenol MClF plug for attaching cable to microphone.
Stand Adapter Thread: %"-27
Dimensions: Length, overall (with adapter) 7 inches (177.8 mm). Length, overall
(microphone only) 4943 inches ( 11 1.1 mm) . Body Diameter 1 inch (25.4 mm) . Finish: Satin Chrome.
General: Model "777" series microphones are pressure-operated, diaphragm type
crystal microphones. The crystal used is a Bimorph, Rochelle Salt unit. The crystal
has been specially moisture-proofed to provide protection against damage due to prolonged
exposure at high humidity.
Applications: Model "777" series microphones are designed for voice and music
reproduction and are ideal for recording on tape, wire or disc; fixed or mobile public
address systems; call systems; amateur communications; and similar uses. These
microphones are especially suitable for those applications involving partial or complete
concealment. When used vertically (microphone pointing straight up), the performers
may be placed all around the microphone without frequency discrimination. The
"777" series microphones are rugged units and are recommended for use where
good quality is required at low cost.
When used with a lavalier cord the "777" series is ideal for public speakers and
lecturers ; teachers and instructors ; demonstrators; and all similar applications where
freedom of both hands is necessary. The cord clips easily to the microphone, can be
easily fastened around the wearer's neck, and readily removed.
Operation: No polarizing voltage is required for crystal microphones.
Crystal microphones may be seriously damaged if accidentally connected to loud
speaker or power supply outlets carrying high voltage. Check your connections