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I have a Kenwood TS530sp. It shows 180 watts out on cw and only 20 watts out on 20 meters

Discussion in 'Radio Circuits, Repair & Performance' started by KA6TZN, Jul 16, 2019.

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  1. KA6TZN

    KA6TZN Ham Member QRZ Page

    Just purchased an MFJ 822. I am showing 180 Watts out on cw but only 20 watts out on 20 meters. SWR 1-1.5 and get good signal reports. Why would this happen?
     
  2. KV6O

    KV6O Ham Member QRZ Page

    Not sure what you're saying... 180W on CW and 20W on 20 meters is comparing different things. Assuming you mean 180W out on CW ON 20M, and 20W out on SSB on 20M, then this is probably normal given that the 822 does not appear to be a peak reading wattmeter. 20W would be about right for average power. If you whistle, you'll probably hit 100W or so.

    And, if you're really getting 180W out on CW, you are waaaay over driving it, you should set it for around 100W. Your tubes, and other hams on the band will thank you.

    Lastly, if you're getting good signal reports, then it's all good!
     
    K9ASE and WA7PRC like this.
  3. W5RKL

    W5RKL Ham Member QRZ Page

    First, the TS-530 is not capable of producing "180 watts" OUTPUT. For the TS-530
    to produce 180 watts "output" the DC input power would have to be "300 watts"
    and that's not possible with a TS-530.

    A couple of reason you are seeing wrong watt meter indications

    1. Tuning transmitter into a bad load resulting in false meter indications
    2. Faulty watt meter
    3. Improper transmitter tuning

    The MFJ-822 watt meter is an average watt meter not a peak reading watt meter.

    The TS-530 final amplifier operates in Class AB1 which has a typical Power input to Power output
    percentage of 60%.

    The TS-530's CW mode "DC Input power" specifications is 180 watts "input" feeding a stable 50 ohm
    load (50 ohm dummy load) and at 60% efficiency would result in an approximate power output of 108 watts
    not 180 watts.

    180 x 0.6 = 108 watts

    During normal voice transmissions with the TS-530 tuned properly and the MIC gain set for ALC meter peak
    indications not to exceed the top of the ALC scale, will result in approximately 20 to 30 watts peak output
    indication on an average watt meter such as the MFJ-822 watt meter.

    Note, at max power output into a 50 ohm dummy load, the HV and IP meter indications. Multiply the HV
    by the IP meter indications will give you the "DC" input power. For example, let's say the HV is 725VDC
    and the IP is "250ma". The DC input power would be approximately 181 watts

    725 x 0.250 = 181.25 watts input

    This would result in an approximate power output at the rear panel SO-239 into the 50 ohm dummy load
    of 108.75 watts.

    181.25 x 0.6 = 108.75 watts output

    Limited power output on a specific band can be caused by alignment issues.

    If you don't have a 50 ohm dummy load then you need to get one. There are a number
    of 50 ohm dummy loads available such as the MFJ-260C 300 watt limited carrier
    time dummy load (see the manual for details on limited time for steady carrier).

    If you don't have the TS-530 manuals, you can download them from my website. Click the link below then scroll
    down to the Kenwood listing and click the appropriate manual links to download the pdf files.

    https://w5rkl.com/manuals/

    73
    Mike W5RKL
    https:..www.w5rkl.com
     
    Last edited: Jul 16, 2019
    K9ASE, WG7X, K7TRF and 2 others like this.
  4. WA7PRC

    WA7PRC Ham Member QRZ Page

    And, the typical AVERAGE power of the human voice is around 25% of peak.
    Fun fact: human hearing responds to the AVERAGE level.
     
    AF7XT likes this.
  5. KA6TZN

    KA6TZN Ham Member QRZ Page

     
  6. KA6TZN

    KA6TZN Ham Member QRZ Page

    Thanks for your reply just read my post and doesn't make good sense, was tired. It was a little less than 110 watts out on cw 20 meters and about 20 watts on ssb on 20 meters. I'm a little dislexic . I need to get a dummy load and whistle (already loaded with dummy but need a physical one) Have no degree in electronics was 55 yrs plus in Respiratory Care now have more time for Radio. Thanks, all is good!
     
    K9ASE likes this.
  7. KA6TZN

    KA6TZN Ham Member QRZ Page

     
  8. KA6TZN

    KA6TZN Ham Member QRZ Page

    Thanks for all the information. Have the original manual purchased the radio in 1984 I believe and have used it since. Obviously read it wrong. I also may be a little dislexic with that 180 reading. I read my post this AM and didn't read well, was a little tired. Would appear I need to purchase a dummy load, have plenty of dummy going on but could use a physical one! Retired after 55+ years in Respiratory Care, the body can correct most of our insults, electronics are a little different. Thanks again!
     
  9. K7TRF

    K7TRF Premium Subscriber QRZ Page

    That makes more sense and is completely normal when reading SSB power with a typical average reading watt meter.

    CW is a continuous power mode, when the key is down the transmitter puts out full power. In SSB mode your RF output power follows the voice envelope and human voice speaking normally has an average power about 20% to 30% of peak power. A typical average reading RF watt meter is not fast enough to capture the fast peaks of human voice and displays the average power level. There are ham grade active peak reading RF power meters that will capture peak SSB power but they typically cost a bit more and they all require power to operate in peak capture mode(not just power to light up the panel lamps).

    With an active peak reading RF power meter you'll see full power in both SSB mode and in CW mode but with a typical average reading watt meter CW will read full power and SSB when driven by normal voice will read about 20% to 30% of that or a bit more with the speech processor engaged.

    When operating in SSB mode, keep a loose eye on your TS-530's ALC meter which not only tells you about appropriate audio drive levels but also tells you your rig is reaching or nearing peak output power. A properly aligned ALC meter in a Kenwood hybrid is set to begin deflecting when RF output power reaches 95% of full power and hits full ALC scale very near 100% of full RF output power. If you see the ALC meter hitting full ALC scale on your louder voice peaks then it's telling you that your rig is hitting full transmit power at those moments.
     
    Last edited: Jul 16, 2019
    WA7PRC and WG7X like this.
  10. W5RKL

    W5RKL Ham Member QRZ Page


    You don't need to "Whistle" into the microphone!! You simply need to tune the transmitter properly by
    following the operator's manual transmitter tuning procedures, with the transmitter connected to the
    dummy load. Once that's accomplished, set the Mode switch to either side band, set the meter switch to
    ALC, and while speaking in a normal voice level about an inch from the microphone in transmit,
    adjust the MIC gain so the voice peaks don't exceed the top of the ALC scale.



    73
    Mike W5RKL
    https://www.w5rkl.com
     
    WA7PRC and WG7X like this.

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