|Discontinued Headphones / Boomset|
The Heil Quiet Phone Pro is a refinement of the original Heil Quiet Phones. The active noise canceling technology uses two small microphones placed deep inside each headphone speaker and wired to a differential amplifier that can switch them in or out of phase. As the microphones listen to the outside ambient noise as well as the headphone audio from the rig, stereo, or armrest jack on a plane, the out-of-phase background noises are greatly reduced, particularly in the lower-frequency range (below about 400 Hz).
The Quiet Phone Pro is available as a stand-alone headset for shortwave listeners, consumers or CW-only operators. But it can also be converted to a boom set with one of five boom-microphone options. The boom system of the Quiet Phone Pro features a brass insert imbedded into the headset. The boom then is affixed to the earmuff using a large thumb screw that securely holds the boom in place. The mount is rugged, the boom is totally flexible, and as a result the boom can be adjusted to hang from the left or right ear of the operator, as desired. Special attention has been directed, as well, toward RFI suppression. Both ferrite beads and RF bypass capacitors have been employed in the Quiet Phone Pro, making it much less susceptible to RFI problems than are other noise-reducing headphones. There is no in-line box for PTT control, as on the earlier Pro Set Quiet Phones.
The Quiet Phone Pro is powered by a single AAA battery (typical life: about 70 hours), and it includes its own volume control. The Quiet Phone Pro folds inward for easy packing when traveling, and its audio cord is detachable at the headset. Two cords are packed with each QPP: one is a coiled cord with a right-angle 1/8" (3.5 mm) plug that fits into most airliner arm rests (or Ham rigs), and the other is a 6-foot HeilWire straight cable, also with a 1/8" plug. Both plugs are gold-plated! An adapter for ¼" phone jacks is also included.
To convert your Heil Quiet Phone Pro headphones into a boomset you will need to order the appropriate MB-1 boom and the appropriate AD-1 adapter (both sold separately). Please note that MB-1 booms are no longer available. Therefore the Quiet Phone Pro headphones can no longer be converted to a boomset.
Safety Reminder: It is dangerous and illegal to use dual earcup headphones while driving. Loud volumes for sustained periods may damage your hearing.
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