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Collins 189A-2 external hybrid phone patch accessory for the KWM-1 / 75A-4 / KWS-1 / 312A-2 in Very Nice Condition

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MPN:
189A-1
Condition:
Used
Shipping:
$12.00 (Fixed Shipping Cost)
  • Collins 189A-1 External Hybrid Phone Patch in excellent condition. Classic Collins accessory for phone patch operation, allowing telephone line connection to your transceiver for third-party or remote contacts. Designed for use with Collins KWM-1, KWS-1/75A-4, and compatible with S-Line/KWM-2 equipment. Features hybrid transformer circuitry for clean audio balancing and isolation. Simple terminal connections – easy setup
  • Collins 189A-2 external hybrid phone patch accessory for the KWM-1 / 75A-4 / KWS-1 / 312A-2 in Very Nice Condition
  • Collins 189A-1 External Hybrid Phone Patch in excellent condition. Classic Collins accessory for phone patch operation, allowing telephone line connection to your transceiver for third-party or remote contacts. Designed for use with Collins KWM-1, KWS-1/75A-4, and compatible with S-Line/KWM-2 equipment. Features hybrid transformer circuitry for clean audio balancing and isolation. Simple terminal connections – easy setup
  • Collins 189A-1 External Hybrid Phone Patch in excellent condition. Classic Collins accessory for phone patch operation, allowing telephone line connection to your transceiver for third-party or remote contacts. Designed for use with Collins KWM-1, KWS-1/75A-4, and compatible with S-Line/KWM-2 equipment. Features hybrid transformer circuitry for clean audio balancing and isolation. Simple terminal connections – easy setup
$59.99
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Description

Collins 189A-1 external hybrid phone patch accessory for the KWM-1 / 75A-4 / KWS-1 / 312A-2 in Very Nice Condition

 This Phone Patch is in excellent cosmetic condition and has the Matching knobs for the KWM-1 / 312B-2 station but these units were also used in the 75A-4 / KWS-1 / 312A-2 set.

I have not tested or used this phone patch but there is very few things to go wrong in this simple circuit.

 

Collins 189A Phone Patch (often referred to as 189-A or 189A).
 
 
This is a vintage external hybrid phone patch accessory from Collins Radio, designed for amateur radio use in the late 1950s/early 1960s era. It enables telephone line interfacing for "phone patching" — allowing a remote telephone user to transmit and receive over the air via the connected transceiver (with proper VOX or manual switching and legal compliance). It uses a hybrid transformer circuit for isolation and balancing between the radio audio and the phone line to minimize hum, sidetone, and feedback issues.
 
 
Key Specifications & Features
  • Type: Hybrid transformer phone patch (low-impedance design).
  • Output Impedance: Approximately 600 ohms (phone line side).
  • Connections: Simple terminal connections to the transceiver's phone patch points and to the telephone line.
  • Controls: Typically includes a balance/null adjustment for proper hybrid operation and transmit/receive switching provisions.
  • Compatibility: Designed for easy integration with Collins equipment via dedicated terminal strips or jacks.
     
    universal-radio.com
Compatible RadiosIt was primarily intended for use with Collins “Gold Dust Twins” (KWS-1 transmitter + 75A-4 receiver) and the KWM-1 transceiver. It also works with later S-Line and KWM-2 series (with possible minor wiring adaptations, as noted in some manuals). Some station consoles like the 312B series incorporated the 189A phone patch.
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