Bearcat 300 "CPR" Mod

Discussion in 'Radio Circuits, Repair & Performance' started by AA7BQ, Sep 12, 2004.

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  1. AA7BQ

    AA7BQ QRZ Founder Administrator Platinum Subscriber QRZ Page

    If you are in possession of one of the classic jewels of the old Electra Bearcat line, the 300 Service Search, and you find it to be dead, the answer maybe in a .75 capacitor...

    After 18 years of great service, my "Service Search" BC 300 no longer worked. This was THE front runner in performance and features that rival many current scanners today. The 300 was of the Electra designed scanners (210, 210XL, 250, 220, 20/20, etc.) As with all these classics, they were "hand made" and revisions were "piece mealed" together during production. This left alot to be desired in the "quality" of the boards and electrical construction / engineering.

    If you have a dead, or dying, BC 300, take a few moments to look at a few things. One would be to go over ALL soldered joints on the PC boards. Notorious for cold solder, or no solder joints, this is sometimes the only fix you need. Bad connections account for 80% of all issues.

    If you find no luck here, and you are also experiencing a dim or blacked out display, but you can still receive squelch, the problem may lie in an electrolytic capacitor. This mod or "fix" is as follows:

    1. Of course with the scanner unplugged, soldering iron plugged in, and covers off, locate cap # C 98 on the "RF" board (the main board). It lies next to a small switching transformer.

    2. Once located, you will find that it has one of 2 values (dependant on production date); either 22uF / 16v OR 47uF / 25v.

    3. Remove this cap with solder wick or a sucker.

    4. Replace this cap. with Radio Shack part # 272-1027, or 47uF / 35v equivalent.

    5. These are axial, so be sure to put the + side on the + side, and the - to the -!! (this is printed on the board to make it easy).

    6. button back-up, plug in, and cross your fingers!!

    If this was the cause of the problem, your scanner should fire up with that classic Bearcat "thump" sound at power up, and watch those bright "rolling zero's" go flying by.

    Not responsible for damage. This worked in my 300 and another friends that I fixed as well.

    KK7AC
    Andrew Smith

     
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