Cobra CA-75 Power Microphone series
Upgrade Changes And
Microphone Wiring diagram
Microphone Identification Page
Courtsey Of Andrew Cody
Miscellaneous Parts and Data Additions
Reference Section and
Modification - Enhancements Section
Cobra CA-75 [M75] Series made after 1999, Black case with Red LED. Prewired for 4-pin or 5-pin radios for Uniden and Cobra.
Cobra CA Series
Truckers Series by Barjan, Road-pro, High-Gear,Diesel and Truckspec. Yellow LED, Woodgrain case style, wired for 4-pin Uniden.
Generic Barjan, Road-pro, High-Gear,Diesel and Truckspec. Blue LED - prewired for 4-pin UNIDEN/Cobra.
This section covers the CA-75 Power Microphone and related power mikes that use the same guts, or innards. Since the PCB mounted inside is found in many different Power-Microphones - I felt it useful to consolidate at least 4 different types of microphones into one area to help in reference and repairs.
An exploded view is offered to help determine if the mods contained here will help you. Check to see if the PCB and Mic Element holder is like the one you're working on. Clicking on the Graphic will bring up a page to let you see the front and rear of the PCB to help you. You can return to this spot from that page.
As shown on the left, the Microphone contains a small PCB with a control knob to control the output level of the microphone. This has the 4-pin plug wiring - look closely to where the grommet is, you will see a yellow sleeve over two wires soldered together at this area.
A battery compartment contained a 9 volt battery required for use in the back of the case.
This particular Microphone uses a Red LED to notify the user the Microphone was working and indicated the status of the battery. By engaging the key on the left side panel of the face - if there wasn't enough power from the battery to make the amp work - it didn't light.
Option of purchasing a 4-pin or 5-pin Mic Plug wired for specific radios listed on the back of the package.
It was pre-wired for Uniden and Cobra radios that used a 4-pin jack.
A separate package of this same Microphone was also made with a 5-pin plug wired for radios the required separate RX/TX Switching that was not tied to ground at the Microphone.
However, as with any product, solely relying on this color-code information is not reliable. Changes and different manufacturers were used as the years progressed for this model - so color coding and actual value of the components listed may be different.
They designed the PCB with a 4-pole, Dual-Throw, Spring return switch for the PTT [4PDT] with one set of contacts unused allowing for extended levels of relay and switch control if the end user had the proper cord and plug to use. The Grommet that acts as a strain relief used a simple crimp and could be removed and reset to handle other cords that had extra wires.
In later model years, the Cobra and Uniden models that required a 5-pin plug were consolidated into straight 4-pin standard design. This occured in the years of 2002 to 2004 when older radios stock was depleted and they no longer offered the older platform radios.
Subsequently, a third-party market for 4-pin radio Microphones allowed for other companies to sell this Microphone under various brands - some listed above. This also changed the color coding of the Mike Cords, some cords follow RJ color coding as if they are using 4-wire phone cord, while others went to 3-wire with different color coding - only shield being the 4-th wire being common.
The main purpose of this project is to help others that needed a Schematic and Wiring diagram for this Microphone. I also have a trick or two you can do this Circuit Design to improve the performance and level sensitivity, and hopefully, you're enjoyment.
To continue, you can go on to the next page which contains the Schematic, Component layout and list, and Mic wiring guide.
Note to Modem-based USERS!:
Disclaimer: Although the greatest care has been taken while compiling these documents,
we cannot guarantee that the instructions will work on every radio presented.
For contact information and corrections please
send a brief Email to Handy Andy
or to the host website; CBTricks.
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