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Extended TX Kit for the 6400M

Didier F6DXE
Didier F6DXE Member ✭✭

Hi, is any one using the Extended TX Kit for the flex radio on 630m?

I do transmit on 630m with the flex 1500 and did it for a while with the 3000 witch I sold.

I find out that 630 m was not available directly on my new 6400m and saw this ad about the extended TX kit.

The 5 watts of the 1500 are not enough on this band due to the loss in the transmission line and the antenna that is too short for 275 Khz.

I cannot find any description on what for bands are added with this kit.

Any info will be welcome


Didier F6DXE


  • VE7ATJ_Don
    VE7ATJ_Don Member ✭✭✭

    HI Didier... I'm not aware of a TX Kit from or for the Flex. If you could post a link to where you got it from, we may be able to help more.

    For most of us, TX output on 630m is only available via the XVTR port and is only a couple of milliwatts. What would be needed is an amplifier of some kind. (I'm not even sure there IS an XVTR port on the 1500....)

  • Hi Don,

    Here is the link , it seems to be a Flex-radio product: https://www.flexradio.com/products/flex-6400-6600-extended-transmit-module/

    You can find the installation guide in several languages on Internet.

    I would like to extend my possibilities on 630 m and I am curious about the possibilities of the extension board.


  • VE7ATJ_Don
    VE7ATJ_Don Member ✭✭✭
    edited September 2022

    Hi Didier... the module you are refering to is primarily for hams taking part in US Military operations (MARS), etc. and the description is quite specific as to who/how it is to be used.

    "This module is required for MARS, Shares, or other users who require out of amateur band transmit capabilities. An approved and in-date government-issued license is necessary to purchase this option. Once the Extended Transmit Module is installed, a TURF file is required to activate the module and can be provided by our technical support team via a HelpDesk support ticket."

    Flex has confirmed in other threads, that the 6000 series' main transmitter cannot output on 630m (nor 2200m).

    The only way to transmit on the lower frequencies is via a power amplifier attached to the XVTR (transverter) output.

  • Ok, I did ask for the Mars extension of my old Flex 3000, some years ago, and did receive the proper TURF file needed for the 60m band allowed here in france.

    I will send a mail to the helpdesk, thank's for the answer


  • David Decoons, wo2x
    David Decoons, wo2x Member, Super Elmer Moderator

    630 meter TX is only available as low power from the transverter port. You would need to use an external amp designed for 630m.

    The extended transmit module is for MARS/SHARES frequencies above 160 meters. You can contact Flex sales for more details.

    73 Dave wo2x

  • Didier F6DXE
    Didier F6DXE Member ✭✭

    Thanks Dave, I will contact them as the kit seemed to be made for 630 m.


  • w7azc
    w7azc Member
    edited December 2022
    What kind of license? Amateur Radio License?(An approved and in-date government-issued license is necessary to purchase this option.)
  • Mike-VA3MW
    Mike-VA3MW Administrator, FlexRadio Employee, Community Manager, Super Elmer, Moderator admin

    The 6300 can transmit on 630M on the Transverter port at 10dbm. You will require an amplifier to bring it to a bigger power.

    It is NOT possible to transmit at any power higher than that or on an ANT1 or ANT2.


  • Didier F6DXE
    Didier F6DXE Member ✭✭

    Thank you guys , I forgot to answer.

    I am looking for an amplifier for the band now



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