Bridgecom repeater?

Discussion in 'Ham Radio Discussions' started by WA2NAN, Sep 20, 2019.

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  1. KA9JLM

    KA9JLM Ham Member QRZ Page

    How did you test that ? Did you have the squelch wide open while the transmitter was transmitting a tone ?
    Last edited: Sep 25, 2019
  2. WA2NAN

    WA2NAN Ham Member QRZ Page

  3. WA2NAN

    WA2NAN Ham Member QRZ Page

    I just had a call from Bridgecom's IF designer and tech. He asked about my problem and said he was assigned to the project of fixing it. I told him that the squelch curcuit had to be modified so it could be adjusted nearly down to the noise floor before closing. He said that he and his team would be working on a way to expand the squelch range possibly thru firmware or software fix. Also said they would like to from others with the same issue...Kerry-wa2nan
    KA9JLM and WJ4U like this.
  4. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    Sounds like a plan!

    Perseverance pays off...sometimes.:p
  5. KA9JLM

    KA9JLM Ham Member QRZ Page

    Normally tone squelch decodes the tone at the discriminator.

    If the signal is not good there, Noise in noise out. When you force audio to pass the repeater will just transmit noise.

    The duplexer may just need to be re-tuned for that repeater pair and antenna.

    Repeater systems are not Plug and Play, If you want them to work properly.
    Last edited: Sep 26, 2019
  6. K9STH

    K9STH Ham Member QRZ Page


    Definitely a matter of definition! What you are calling "full quieting" was known as "limiter saturation", the point at which additional signal level would not result in any more limiter current. "Full quieting" was the point at which any noise, on the signal, ceased to exist in speaker audio.

    Most of the receivers, manufactured by the major two-way radio companies had 2-limiter circuits that were, basically, in series. When aligning the receiver, the 2nd limiter was metered and when that reading reached saturation, the test set was then connected to the 1st limiter. Alignment continued until saturation was reached with the 1st limiter. Of course, the input signal level was reduced, in steps, to allow maximization of the receiver sensitivity.

    At least Motorola, General Electric, and RCA, had test sets that plugged into a central metering jack and then the meter connection was moved by a rotary switch. Motorola had a panel, with multiple meters, that did not require any switching, because a separate meter was monitoring all circuits at the same time. For use by my technicians, for bench work, I had the multiple meter assemblies and the smaller, switched meter, test sets for field operation. Also had a couple of different General Electric test sets. Although I never had a commercially produced test set for RCA, I did home-brew a complex test set that allowed tuning of the RCA units.

    Glen, K9STH
  7. W5RDW

    W5RDW Ham Member QRZ Page

    Kerry, please keep us informed on this Forum of your conversations with Bridgecom. I'm not too far away from putting up a Bridgecom 220 MHz repeater at a nearby University here in Dallas. It's antenna will be on a tower with an omni radiation pattern with a fairly good HAAT.
  8. K7JEM

    K7JEM Ham Member QRZ Page

    The point I am trying to make is that "full quieting" does not occur at or near .2uV in any radio, it will be around 15+ dB above the RF level required for 20 dB quieting. On several posts on this thread you have indicated that .2uV is near full quieting. This is an erroneous statement that you do not somehow understand.

    Yes, your definition is correct:
    "Full quieting" was the point at which any noise, on the signal, ceased to exist in speaker audio.

    And that is exactly what I am saying. This can be readily measured by using a good AC voltmeter, or TMS at the speaker output. If you do this measurement, you will see that I am correct. It takes much additional RF input signal to get from "20 dB of quieting" to "full quieting". The latter would be on the order of 45 to 55 dB of quieting, depending on the particular RX being tested. It should be obvious to understand that you don't get from 20dB of quieting to 50dB of quieting with a couple of dB increase in RF signal.

    Yes, I have worked in the LMR field for 42 years, so I know what the definitions are, and how to make these tests. Yes, I had the same multiple meter setup, and the same single meter Motorola test box. Yes, I had the same GE test meter. (Images from Repeater Builder website)


  9. WJ4U

    WJ4U Ham Member QRZ Page

    uh-oh, someone on the internet is wrong? :oops:
  10. WB2WIK

    WB2WIK Platinum Subscriber Platinum Subscriber QRZ Page

    I remember the days of "full quieting" vs. "DFQ" ("dead" full quieting) and all the variations, going back to the late 60s.:)

    Also never cared.

    20 dB quieting, which certainly is not "full" quieting, is good enough. 12 dB SINAD is similar.

    We're not broadcast stations, we're just chatting.:p

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