Welcome to the FlexRadio Community! Please review the new Community Rules and other important new Community information on the Message Board.
Need the latest SmartSDR or 4O3A Genius Product Software?

SmartSDR v4.1.3 and the SmartSDR v4.1.3 Release Notes
SmartSDR v3.10.15 and the SmartSDR v3.10.15 Release Notes

The latest 4O3A Genius Product Software and Firmware
If you are having a problem, please refer to the product documentation or check the Help Center for known solutions.
Need technical support from FlexRadio? It's as simple as Creating a HelpDesk ticket.

Why is the RF gain control not continuous?

WK2Y
WK2Y Member ✭✭
in SmartSDR for Windows

Just out of curiosity, why is the RF gain control limited to only a few fixed levels, e.g., +10db +20db etc. When I think back to my old HQ-110A. if I remember correctly, it was continuous control. Was the sensitivity control something different than the current RF gain control?


Thanks and 73,

Bob, WK2Y

Best Answers

  • Martin AA6E
    Martin AA6E Member ✭✭✭
    edited March 2021 Answer ✓

    oops

  • Mike VA3MD
    Mike VA3MD Member ✭✭
    Answer ✓

    I have a high noise level on 80\40 meter band, I find that the fixed Preamp gain works the best. It is a constant value that make it easier to use. Most modern radios of the last 25 year have a fixed gain preamp with only one selection on or off. With flex 6xxx the use of the preamp and the AGC T makes 80 meters usage for me, there is some great video's that Mike VA3MW has made to take a look.

    https://www.youtube.com/watch?v=OJ36HMBQS7U

    Mike, VA3MD

Answers

  • Martin AA6E
    Martin AA6E Member ✭✭✭

    In a word, yes. The Flex 6xxx just appears to switch in 1 or 2 fixed gain preamp stages (or attenuators). Old tube radios would have a potentiometer that continuously varied the gain of a single RF stage. The modern radios are much better. You don't need to adjust RF gain very often.

    I yearn for the days when we got real schematics (even block diagrams) for our radios, so we could understand how they work a little better.

    73 Martin AA6E

  • K0FLY
    K0FLY Member ✭✭✭

    Martin is correct. The Flex RF gain control selects an attenuator or fixed gain RF preamps. Other manufacturers call this function RF preamp on/off and Attenuator on/off. If you are look for a function similar to the RF gain on analog radios use the Flex AGC Threshold slider. I lik e the AGCT function better.

    Gayle K0FLY

  • Mike VA3MD
    Mike VA3MD Member ✭✭

    I have a high noise level on 80\40 meter band, I find that the fixed Preamp gain works the best. It is a constant value that make it easier to use. Most modern radios of the last 25 year have a fixed gain preamp with only one selection on or off. With flex 6xxx the use of the preamp and the AGC T makes 80 meters usage for me, there is some great video's that Mike VA3MW has made to take a look.

    https://www.youtube.com/watch?v=OJ36HMBQS7U

    Mike, VA3MD

  • WK2Y
    WK2Y Member ✭✭

    Yes, the whole thing that got me thinking about this was Tim's presentation at QSO Today. Great stuff.

    Thanks.

Leave a Comment

Rich Text Editor. To edit a paragraph's style, hit tab to get to the paragraph menu. From there you will be able to pick one style. Nothing defaults to paragraph. An inline formatting menu will show up when you select text. Hit tab to get into that menu. Some elements, such as rich link embeds, images, loading indicators, and error messages may get inserted into the editor. You may navigate to these using the arrow keys inside of the editor and delete them with the delete or backspace key.

Comment As ...

Categories