I'm not electronically proficient

Discussion in 'Microphones, Speakers & Audio Processing' started by K4BOM, Jan 17, 2021.

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  1. K4BOM

    K4BOM Ham Member QRZ Page

    In fact, it absolutely amazed me when I was told that I had passed my Extra class examination.
    So, please, just laugh at my non-expertise, and try to help me out.

    Problem: I own a 7300 and wished to augment the transceiver with an external speaker.
    I found one I liked, and tried to hook it up, but the volume is really weak even with the radio wide open
    AF wise.
    I looked up the specs of the 7300 and found that it handles an 8 ohm speaker. Check...the one I bought is 8 ohms. The gizzy attached to the speaker looks like the pictures attached. (Note technical terminology)
    pic 1.jpg pic 2.jpg pic 3.jpg
    I wired it up using the connections shown in pic 2 as it was already soldered by the previous owner.
    Should I change the wires to different points to get this speaker to play with increased volume?

    Go ahead and laugh....I am laughing at myself!

    Any input is appreciated.
  2. KI4ZUQ

    KI4ZUQ Ham Member QRZ Page

    Speaker is 8 ohms by itself. Your radio audio output is 8 ohms. Bypass that matching transformer. That's my theory based upon what you described (weak sound output) and your pictures. So test my theory by disconnecting at least one speaker lead from the transformer secondary (either common C or 8 ohm) and rig up a plug to your radio external speaker jack and alligator clips to the speaker directly. Report results with either praise (if it works) or ridicule (if it doesn't)! Har, har!

    By the way, I am old school from vacuum tube days and what you have was pretty common back then to match the high impedance of a audio amp out to the low impedance of the dynamic (magnetic) speaker coil.
    KL7KN likes this.
  3. AJ4WC

    AJ4WC Ham Member QRZ Page

    That looks like a Public Address transformer, designed for a 70 volt system. I can’t be sure because I can’t see the specs on the primary.

    Nonetheless, you don’t need the transformer. Bypass it and connect the speaker directly.
    WE4E and WN1MB like this.
  4. K4BOM

    K4BOM Ham Member QRZ Page

    Hokey Smokes, Bullwinkle. You were exactly right!
    KI4ZUQ comes in at first place by a nose. One hour earlier than AJ4WC.
    Both had the same correct answer!
    This easy fix reminds me of my father. When he would go into his shop to fix something, he would take it all apart and then reassemble it and always had parts left over. He'd say, "Just as I thought, there were too many parts in there."
    Anyway, a BIG THANKS for setting me straight.
    Anyone want the "gizzy" I have left over??
  5. KI4ZUQ

    KI4ZUQ Ham Member QRZ Page

    That's the way it works! You ask a question, two curmudgeons give the same answer which then means it is probably right. THEN you do the test to see if it is right. Only the physical test proves it!
    AJ4GQ likes this.
  6. K4BOM

    K4BOM Ham Member QRZ Page

    I think I qualify for the "curmudgeon club". I'm 73.
    KI4ZUQ likes this.
  7. KI4ZUQ

    KI4ZUQ Ham Member QRZ Page

    You may want to ask the guys over at antiqueradios.com if they want the "gizzie" since they restore all kinds of old radios. This kind of thing is getting rare...

    Thanks for the tech feedback! Tech on, learn things!
  8. AJ4WC

    AJ4WC Ham Member QRZ Page

    And, then someone jumps in and, with no provocation, insults those that were trying to help.
    WD8T and KI4ZUQ like this.
  9. KL7KN

    KL7KN Premium Subscriber QRZ Page

    Hey - its the Zed.

    I've posted stuff only to have an army of folks show up later and tell I'm wrong. . As with anything on the web, free advice it worth what it cost you to obtain....

    It's all good

    Happy for the OP who got his question answered/solved.
    KI4ZUQ likes this.
  10. K1LKP

    K1LKP Platinum Subscriber Platinum Subscriber QRZ Page

    WAIT A MINUTE,..................

    ARE U


    KI4ZUQ likes this.

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