Do you need a 40 Amp to transmit 200w on Kenwood TS 480 HX?

Discussion in 'Ham Radio Discussions' started by K7HN, Aug 13, 2019.

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  1. K7HN

    K7HN XML Subscriber QRZ Page

    Well, I suppose the questions already asked above in the title Ha ha ha.. I’ve looked at way too many radios to purchase (Still love the Yaesu FTDX 3000) and truly by accident stumbled upon the Kenwood TS 480 HX at Ham Radio Outlet today.

    A friend of mine who is more knowledgeable than I,told me I would need a 40 amp circuit to my shack to be able to use this radio to transmit at full 200 W and also it would need two power supplies.

    I was impressed with this little radio… I love to do DX very much in amateur radio. That’s at the top of my list so can anyone give me their review of this radio as to DX capabilities compared to the 3000 and answer my question as to its power needs?

    Thanks a LOT and 73!


  2. WC5P

    WC5P Platinum Subscriber Platinum Subscriber QRZ Page

    You need a 40 amp or more DC power supply. You do not need a 40 amp AC power outlet. An ordinary 20 amp power outlet would be sufficient.
    KK5JY, N5PAR, K7HN and 1 other person like this.
  3. AG6QR

    AG6QR Premium Subscriber QRZ Page

    The 200W version of the Kenwood TS-480HX has two DC inputs, each requiring "less than 20.5A" at 13.8VDC. You could supply them with one single 41A supply, but 41A supplies aren't nearly as common as supplies of 25A to 35A, so it might be most convenient to use two supplies, with each one capable of at least 20.5A.

    Because P=IE, 41A * 13.8V is equivalent to about 4.7 A at 120V. There will be a penalty due to the inefficiency of your power supply, but at 70% efficiency (which is pretty awful), that would still amount to less than 7 amps, or less than half of a typical residential 15A branch circuit. Unless your present wiring is seriously overloaded, you don't need to rewire your house for a 200W radio.
    KD8DEY likes this.
  4. KM4FVI

    KM4FVI Platinum Subscriber Platinum Subscriber QRZ Page

    Larry, you are singing my tune! I also have a TS-480 HX and a 710G as mobile units in my Durango. Very interesting that you are going down the same path as me. As mentioned earlier, you need 40 amps DC not AC. My 480 handles DX very well with my Tarheel 200HP screwdriver antenna with a capacity hat on it. I am a Kenwood fan from years ago and still have my TS-820S station from many years ago (1984 if my memory serves me). The 480 will need the preamp on to pull in the DX signals. A good DSP powered speaker will also help. My 480 is an older rig and doesn’t have an external speaker outlet unlike the newer versions.

    Good luck in whatever radio you choose!

    K7HN likes this.
  5. NL7W

    NL7W Premium Subscriber QRZ Page

    Two supplies would work. Just be sure to set them both for the same regulated voltage, say 14.0 or 14.2 Vdc.
  6. K7HN

    K7HN XML Subscriber QRZ Page

    My friend, if I could hit LOVE instead of “Like” on this answer I would LOL! Thank you so much for your help!

    Blessings and 73!

  7. W4ZD

    W4ZD Platinum Subscriber Platinum Subscriber QRZ Page

    Not much difference between 100W out and 200W out, less than an S-unit. I might spring for a 400W-500W Xcvr, but 200W is peeing in the ocean. The presumably higher cost would be better invested in the antenna.
    N5PAR likes this.
  8. WA9UAA

    WA9UAA Ham Member QRZ Page

    You're better off with an RS-50 or the like, one supply is less complicated by far to setup and use.
    AI3V and KD8DEY like this.
  9. AG6QR

    AG6QR Premium Subscriber QRZ Page

    While the RS-50 is rated for 50A peak, it's only rated for 37A continuous, below the radio's 41A current draw. That's probably fine for SSB phone use, but could be a problem for high duty cycle digital modes. Then again, maybe one shouldn't run such modes at full power anyway.

    A supply (or pair of supplies) with a bit more capacity would run cooler and allow one to operate key-down indefinitely without risking power supply issues.
    K0UO and WA9SVD like this.
  10. K7HN

    K7HN XML Subscriber QRZ Page

    Thanks for your reply my friend.
    WA9SVD likes this.

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