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N4BAA Member
If I want to hook up an Advanced Receiver Research 6M Preamp, how is this connected correctly to a Flex 6600? Very intuitive for a Flex 6700 with the RCV ant In/Out, but not so clear on the 6600. Thank you.
Jose N4BAA


  • KD0RC
    KD0RC Member, Super Elmer Moderator

    Hi José, there are a couple of different models of preamps made by ARR. Some switch automatically and some not. Which one do you have?

    In general, the Flex has way more than enough front-end gain, even on 6 meters. Is there a particular reason that you are looking to use a preamp?

  • Mike-VA3MW
    Mike-VA3MW Administrator, FlexRadio Employee, Community Manager, Super Elmer, Moderator admin

    I agree with Len. Before you add another preamp, you want to make sure you are not 'noise bound' already.

    When using a preamp on a 50MHz (6 meters) band in a FlexRadio or any other radio transceiver, it's essential to find the right balance to avoid being noise-bound. Here are some tips to help you determine if you are using too much preamp:

    1. Monitor the Noise Floor: Start by monitoring the noise floor when you enable or adjust the preamp. The noise floor is the background noise level on the band. If the noise floor increases significantly when you turn on the preamp or increase its gain, it may be an indication that you're amplifying unwanted noise.

    2. Signal-to-Noise Ratio (SNR): Pay attention to the signal-to-noise ratio. As you increase the preamp gain, the desired signals should become stronger, but so will the noise. If the SNR does not improve or decreases as you increase the preamp gain, it's a sign that you might be overdoing it with the preamp.

    3. Visualize the Spectrum: Use the spectrum display on your FlexRadio to visualize the signals and noise. If you notice that the noise floor rises significantly but the desired signals aren't much stronger, you might be adding too much gain.

    4. Pay Attention to AGC-T: Most modern transceivers, including FlexRadios, have automatic gain control (AGC-T) systems.

    5. Listen to the Audio: Listen to the audio quality of the received signals. If the noise becomes overwhelming and drowns out the actual signals, it's a clear sign that the preamp gain is too high.

    6. Experiment with Preamp Settings: Try experimenting with different preamp settings, starting with lower gain levels and gradually increasing it. Continuously assess how the changes impact your ability to receive desired signals versus noise.

    7. Consult the Manual: Review your FlexRadio's user manual or documentation for recommendations on preamp usage specific to your model. Manufacturers often provide guidance on setting preamp levels for optimal performance.

    In summary, the key is to find a balance between amplifying signals and minimizing noise. You want to maximize your ability to receive weak signals without introducing excessive noise. Experimentation and careful monitoring are essential to finding the right preamp settings for your specific operating conditions.

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