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TGXL Operating Specs

John K3MA
John K3MA Member ✭✭

I was reviewing the newly release TGXL Preliminary Manual and the follow statement on Page 6 caused me to search for a actual Engineering definition. I was able to find many statements that used fluff words rather than specifics or provide different duty cycle percentages or provide different maximum transmit time followed by a minimum receive time to try to frame what it means. But I could not find anything specific regarding it's meaning for operation of the PGXL. When I look at it in light of the RF Power spec on Page 8 and then think about the Power Derating function outlined on Page 71 it gets a bit difficult to know in advance how to properly operate with the tuner so you know the specification will not be exceeded and potential damage be done.

Can a bit more actual operating specifics be place on what all this means? Maybe something that gives measurable easily understood criteria like:

Antenna SWR before tuning

Tuning Solution SWR

Mode of Operation

Transmit Duty Cycle, Transmit Max Time

Transmit Power into Tuner

I am not being critical of the TGXL or even the Preliminary Manual but rather just want to be sure that once I press the PTT and put the TGXL in line that I am not exceeding it's ratings.

Thanks, John K3MA

Best Answer

  • Mack W4AX
    Mack W4AX Company Adviser ✭✭
    Accepted Answer

    I won't have time to answer every question here but will fill in a few blanks.

    Here is the latest power/SWR table that will be included in the manual.

    We have run the Smith Chart extensively through modeling and real world testing. If you have poor antennas at 10M and above the TGXL will self protect itself in firmware at certain SWRs. The key here, as we all know, is to have reasonable antennas appropriate for a chosen band. At 28 MHz and above the RF amperage can exceed 30 amps at high SWRs. Please read the opening page of the TGXL manual to understand what an antenna tuner is really doing which is transforming an unacceptable antenna impedance to one that will not damage the power amplifier section. Nothing changes with the antenna.

    The TGXL has been operated by Craig K9CT and Chris N6WM on RTTY continuously during a three day contest. Both are world class operators and contesters. No issues. The TGXL includes an internal cooling fan to keep the inductors and capacitors cool when needed. The key to continuous operation is to have antennas that are reasonably resonant.

    The beta team we have assembled are all great ham radio operators with everything from a very simple station with limited antennas to world class contesters. Some of the testers are world class RF engineers. The TGXL has been tested with non-CAT radios, Icoms (yes the protocol and communication is improved), various amplifiers, and of course the Flex Radio eco system. It has also been tested with the Antenna Genius antenna switch which greatly expands the TGXL capabilities.

    A large number of PGXL early adopters who were promised a tuner will receive their TGXL's via UPS on Thursday or Friday. Shipments of TGXLs are being received at FlexRadio on a regular schedule. I will share that obtaining certain RF components is becoming a challenge and orders for those components are being placed with at least a six month lead time. You can read about these component shortages by Googling how it is affecting the automobile industry and causing major layoffs.

    I am not a FlexRadio employee but have been leading this project for the past 18 months so that I, like you, will have a world class tuner that is unlike any other on the market today.





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


    That is a preliminary manual and hopefully those numbers will be filled in.

    My KPA1500 I had would tell you the derated maximum wattage based on band and actual SWR which was nice, especially on 80 where my SWR near top of the band is higher.


    Dave wo2x

  • John KB4DU
    John KB4DU Member ✭✭✭

    Also, there is no standard for Intermittent Commercial and Amateur Service (ICAS). 50% on to off duty cycle is typical, but some modes like RTTY can be continuous for an extended period of time.

  • John K3MA
    John K3MA Member ✭✭

    It seemed clear that there is no standard otherwise something would have shown up on my search rather than on person saying it means 50% duty cycle 5 min on and 5 off and another saying it is 10 min on and 10 off.

    Since Flex designed the tuner and put together the manual I would think it would be best for someone involved with the Tuner project to comment. At least I would feel better if that was the case otherwise I am left like everyone else to guess and use our best judgement. That would be unfortunate for a $2000 plus piece of equipment.

  • John K3MA
    John K3MA Member ✭✭

    Dave, well I guess it could be as simple as look at the display and always follow the maximum wattage display on the GUI. However, I am not sure that is good enough to determine the correct conditions especially since nothing is provided in the manual that I can find that give us the specific inputs that are used to derive this maximum wattage.

  • Chris DL5NAM
    Chris DL5NAM Member ✭✭✭


    this tuner must be able to do a 100% duty cycle. Why?. Well, it is designed for legal power / up to 2000W, a SO2R ATU is designed and thus in the contest it can be that the PA and the tuner are constantly in operation -> Duty cycle = 100% (worst case)

    If a tuner cannot do 100%, then the ferrite cores of the coils and the capacitors used are probably too weak.

    This does not apply to the TGXL tuner - I think - because it was developed over many yearss until it is now to be sold. So the tuner will definitely be a master piece.

    Practice will then show what he can do.


  • John K3MA
    John K3MA Member ✭✭
    edited June 9

    Yes, I am sure there will be others that test the specs of the Tuner much more than I.

  • Mack W4AX
    Mack W4AX Company Adviser ✭✭

    Oh, and yes, we now have CE certification in addition to FCC certification.


  • ka9ees
    ka9ees Fithian IL USAMember ✭✭✭

    @Mack W4AX

    Nice talking to you this morning. I am looking forward to ordering mine. It will be a 1X3.

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