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Re: FT80's Out Power

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  • bcdlr
    I just ordered a TUT80. I was wondering if this mod would be a recommendation. Are there any other mods that are must-haves? Looking forward to getting this
    Message 1 of 31 , Feb 25, 2011
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      I just ordered a TUT80. I was wondering if this 'mod' would be a recommendation.

      Are there any other mods that are must-haves?

      Looking forward to getting this kit. Been hearing so much about it and I've been wanting to build a new kit.

      73
      Dan KB9JLO

      --- In FtTuthill80@yahoogroups.com, "n1rx" <bruce.beford@...> wrote:
      >
      >
      >
      > --- In FtTuthill80@yahoogroups.com, "Tayloe Dan-P26412" dan.Tayloe@ wrote:
      > >
      > > The more efficient output network that I have simulated involves:
      > >
      > > 1) Changing L4 from 24 turns to 19 turns
      > > 2) Shorting out C58 so that C57 and C59 together provide 2000 pF of C at
      > > that point rather than the current 1500 pf.
      > > 3) Replacing L6 (a FT37-43 core) with a T37-2 core with 22 turns. There
      > > is no tap on this new coil. The coil end points go to pad 1 and pad 2.
      > > Pad 3, where the tap used to go, is shorted to pad 2.
      > >
      > > This simulates well to give a non-critical, class E type output, even
      > > though it is being driven with a less than optimum sine wave input. The
      > > output would be somewhere in the 4.5w range.
      > >
      >
      > I finally got around to performing this mod on my Tut-80. When operating from a 3-cell LiPo battery pack, the output power rose from 2.5 to 3.3 watts. When running from a 13.5V suply, I am seeing about 4.8W. This mod "works as advertised". I would recommend it for any Tut-80. It provides greater efficiency, and reduces the temperature of the finals (and it's associated effect on the VFO).
      >
      > A belated Thank You, and a tip of the hat to Dan!
      > 72/73,
      > Bruce, N1RX
      >
    • Jerry Haigwood
      Terry, I have seen a lot of 7 segment LEDs fail but never a single LED. Since it is a semiconductor, about the only thing that could get it is heat or static.
      Message 31 of 31 , Oct 13, 2011
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        Terry,
        I have seen a lot of 7 segment LEDs fail but never a single LED. Since it is a semiconductor, about the only thing that could get it is heat or static. In case of the 7 segment types, it almost always the heat that destroys them.
        Jerry W5JH

        -----Original Message-----
        From: FtTuthill80@yahoogroups.com [mailto:FtTuthill80@yahoogroups.com] On Behalf Of wa0itp@...
        Sent: Thursday, October 13, 2011 7:05 PM
        To: FtTuthill80@yahoogroups.com
        Subject: Re: [FtTuthill80] Re: FT80's Out Power

        blue LED failed

        Thats odd Ive never seen a failed led.

        72 Terry WAØITP

        ----- Original Message -----
        From: Dave AA7EE <djdaverichards@...>
        To: FtTuthill80@yahoogroups.com
        Sent: Thu, 13 Oct 2011 16:52:50 -0500 (CDT)
        Subject: [FtTuthill80] Re: FT80's Out Power



        Thanks Terry. My ATU is a T match design, so will be pretty useless at suppressing the harmonics. Thanks for mentioning that - guess I'm leaving my Tut80 the way it is for now.

        For some odd reason, the blue LED failed yesterday but luckily I had another one on hand.

        Dave
        AA7EE



        --- In FtTuthill80@yahoogroups.com, wa0itp@... wrote:
        >
        > Hi Dave,
        >
        > I'd think that should work, and you could estimate the harmonic strength with a big rig's s-meter. You could aslo add an LPF at the Tut's output. A T-Match tuner is a high pass configuration so I wouldnt use that design here. Class E is definately worth doing, but I'm going to leave mine alone. My Tut is making 2.5W on 12 volts and is cool and stable. I used a TO-92 heat sink on each final transistor and they are barely warm after a qso.
        >
        > Good luck with the mod.
        >
        > 72 Terry WAØITP
        >
        > ----- Original Message -----
        > From: Dave AA7EE <djdaverichards@...>
        > To: FtTuthill80@yahoogroups.com
        > Sent: Thu, 13 Oct 2011 16:03:35 -0500 (CDT)
        > Subject: [FtTuthill80] Re: FT80's Out Power
        >
        > Although the only way to ensure that my harmonics are in compliance would be to measure them, do you think it would be reasonable to assume that were I to perform this mod to increase the output power and feed the antenna via an ATU, that the ATU would provide the necessary extra filtering?
        >
        > Dave
        > AA7EE
        >
        >
        > --- In FtTuthill80@yahoogroups.com, "n7ve" <dan.Tayloe@> wrote:
        > >
        > > The mod works in spite of the fact that there is a sine wave drive rather than the more desired square wave drive. However, when I tried this modification on my TUT80, I found the harmonics were about 3 dB out of spec.
        > >
        > > The kit has a third harmonic notch built into the output network. Depending on parts tolerances your kit may or may not be FCC compliant.
        > >
        > > Since I could not guarantee that all kits would pass after this change, I did not make this as an official change.
        > >
        > > However, things do run a lot cooler (with more power!) after the modification.
        > >
        > > - Dan, N7VE
        >
        >
        >
        > ------------------------------------
        >
        > Yahoo! Groups Links
        >




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