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 v3.9.19 and the SmartSDR v3.9.19 Release Notes
SmartSDR v2.12.1 and the SmartSDR v2.12.1 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.

Correct settings for TX Delay and RCA TX1 with an external linear amp

PhilM
PhilM Member ✭✭
in Peripherals & Station Integration

I have been using my FLEX-8600 with an SPE 1.5K-FA linear with the following settings

RCA TX1 set to 0 ms

TX Delay set to 12ms

This is based on the Amp's requirement for a 6ms delay for its internal relays to settle down.

Does this look good?

The manual I was looking at was for the 6000 series radio, I am assuming it is very similar to the 8600 requiremennts

Phil, NC3S

Answers

  • PhilM
    PhilM Member ✭✭

    I think this section of the manual will explain why I chose those settings

    "For external amplifier use, the delay should be set to zero for any output that keys the external
    amplifier.     This will ensure the relay will follow the PTT signal exactly.
    The TX Delay setting can be used if the external amplifier has slow T/R relays and requires a longer
    time between PTT and RF Emission.     Unless you are noticing problems with the radio emitting RF
    before the amplifier has switched to transmit position, you should leave the TX Delay set to zero."

    The "RCA TX1" line is the signal to the external amp to make and settle down its relays, at the same time the delay for "TX DELAY" begins in order to wait for the amplifier relay to settle down, with a safety factor of 2X.

    Phil, NC3S

  • Ken Wells
    Ken Wells Community Manager admin

    Leave the TX1 (or TX2, TX3) Delay at 0

    Set TX DELAY to whatever is needed to p[revent "Hot-Switching" the amplifier relays with RF already flowing from the radio.

    This can be 10, 15, 20, or more, depending upon your amplifier, its relay speed, and whether you have a second relay as a "buffer" for the Amplifier's PTT (which would need to add additional TX DELAY)

    NOTE: I also Recommending using a CW DELAY (Hang Time) that is at least as high as the TX DELAY. if not much longer, unless you have a fully QSK amplifier.

  • PhilM
    PhilM Member ✭✭

    OK, thanks. I'm using a SPE Expert 1.5K-FA linear. The manual says it supports QSK and that its relay requires 6ms to settle down. I assume doubling that for a value of 12ms would be a good safety factor.

    The amplifier has not issued any error messages, so I assume all is good with the QSK.

    Phil, NC3S

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