1. You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.
    Dismiss Notice
Dismiss Notice
This forum does not allow a single user to have more than one username. If anyone wants to change their username contact an admin and it will be done. Multiple accounts belonging to the same member will be deleted without warning.

KL203P linear

Discussion in 'Amplifiers' started by Robert Cook Sr, Feb 21, 2021.

?

need to know do I send unit back to seller of and adjustment I can make to linear??

  1. anyone

    0 vote(s)
    0.0%
  2. I'm new?

    0 vote(s)
    0.0%
Multiple votes are allowed.
  1. Robert Cook Sr

    Robert Cook Sr New Member

    Joined:
    Dec 27, 2020
    Messages:
    16
    Likes Received:
    10
    I have a new linear, KL203P truck not running ,dead key 25Watts, truck running around 90 Watts, but either mode wen talking wattage backs up instead of going forward, anything I can do to correct problem?:?


     

  2. sp5it

    sp5it Master of puppets

    Joined:
    Jul 9, 2009
    Messages:
    1,914
    Likes Received:
    2,169
    KL203 need constant supply voltage and 2W AM carrier and 12W SSB PEP.
    Do it and come back with results.
    Mike
     
  3. Robert Cook Sr

    Robert Cook Sr New Member

    Joined:
    Dec 27, 2020
    Messages:
    16
    Likes Received:
    10
    radio putting out 1.5 watts dead key only Am radio but when talking backing up. SWR is less than 1.1.1 on steel whip
     
  4. sp5it

    sp5it Master of puppets

    Joined:
    Jul 9, 2009
    Messages:
    1,914
    Likes Received:
    2,169
    To measure power you must use dummy load and trusted meter. Measuring on antenna is never accurate.
    Mike
     
  5. Robert Cook Sr

    Robert Cook Sr New Member

    Joined:
    Dec 27, 2020
    Messages:
    16
    Likes Received:
    10
    I did that used dummy load
     
  6. NightThumper

    NightThumper Sr. Member

    Joined:
    Nov 8, 2017
    Messages:
    537
    Likes Received:
    1,216
    Mr Cook...the KL203P is only rated for 100 watts max output. When you truck is turned off you’re only supplying 12 volts or less which isn’t sufficient. That’s why when the truck is running and generating 13.8 to 14.5 volts (roughly) you’re seeing more output. Since your driving it with 1.5 watts and seeing 90 watts. I’d say the amp is doing what it’s suppose to.

    Regarding the watt meter backing up when you modulate here’s a couple of observations. Does your meter read PEP or only RMS. You need a peak reading meter that can capture the peaks of the modulated envelope wave as there are two peaks...a positive and a negative. It’s not unusual to see backwards modulating if your meter isn’t reading peaks. Honestly 10 watts short of seeing 100 is nothing. That amp is only specified for 100 watts output. When using just the radio does your meter show forward modulation (I.e. an increase in wattage). If not then you’re seeing exactly what you’re putting into the amp.

    Brad
     
  7. Slowmover

    Slowmover Elmer

    Joined:
    Feb 17, 2015
    Messages:
    5,270
    Likes Received:
    8,281
    Backward swing. Not end-of-world. Some of my radios do that with a KL203 or -P model.

    The following isn’t advice, per se, more that I think I recognize what you’re saying:

    If you know (not guess) radio is 2.5W DK, you’re “okay”. Still better to use real advice above to round off safe operation.

    If this is a big truck (semi tractor) the supplied CB fused circuit is either 10A or 15A. I’ve successfully run the amp plus low DK radio combo that way. But I’d advise a wiring upgrade (fused POS) to give some breathing room.

    Now, depending on several factors and using a separate tuner (PEP Meter would be a better choice), I’ve seen from 50-90W with most radios I’ve used.

    Look into “backward swing” as a search topic.

    And a late WELCOME! to WWDX.

    .
     
    #7 Slowmover, Feb 21, 2021
    Last edited: Feb 21, 2021
    TIN_CAN and codeman like this.
  8. Robert Cook Sr

    Robert Cook Sr New Member

    Joined:
    Dec 27, 2020
    Messages:
    16
    Likes Received:
    10
    Thanks for answers. I only get approx. 1.5 watts dead key with Nissan truck running giving me around 90 watts dead key only change is increase of voltage to Lenear.. I used CB 23 channel back in the 1970's Have equipment used until 1983 when I moved , seemed like I never had time to get back into CB until recently.. I just thought a 50 watt jump with just voltage increase wasn't normal. Years ago I used a Browning marks 111 SSB and am Mark3 am transmitter for years until my move to another state, also have Varmit 350 tube type let over also Popping fuses after 50 year rest. I read these forums to try to learn something from the big guys that know more than me. I had some schooling in the early 1970 's but transitors were just being used then.
    .
     
    #8 Robert Cook Sr, Feb 21, 2021
    Last edited: Feb 22, 2021
    S&W357 and Handy Andy like this.
  9. Robert Cook Sr

    Robert Cook Sr New Member

    Joined:
    Dec 27, 2020
    Messages:
    16
    Likes Received:
    10
    I used a PDC 600 meter and Delta meter to check ,got same reading on both meters
     
    Handy Andy likes this.
  10. Robert Cook Sr

    Robert Cook Sr New Member

    Joined:
    Dec 27, 2020
    Messages:
    16
    Likes Received:
    10
    I have a 2 tube Elkin leaner that show a 40 watt swing using same meter 1 watt dead key a uniden 980 SSB
     
    Handy Andy likes this.
  11. Shadetree Mechanic

    Shadetree Mechanic 808 On The North Side of Dover

    Joined:
    Oct 23, 2017
    Messages:
    4,428
    Likes Received:
    6,842
    Welcome! What radio are you using with the 203? If the meter is swinging backwards, then you are overdriving the amp. If the amp dead keys 90w, then whatever the dead key on the radio is, it needs to be turned down.
    Chris
     
  12. ForestRunner98

    ForestRunner98 917 SoCal

    Joined:
    Feb 9, 2020
    Messages:
    840
    Likes Received:
    1,752
    I agree with ShadeTree. I have the same amp and my radio is set at 1.5w DK. With the amp on it will DK at 30w and swing to 140w or so. This is using a PEP watt meter. I would turn down the power until it DK’s around 25-30w amp on. You have no headroom so it’s swinging back.
     
  13. Robert Cook Sr

    Robert Cook Sr New Member

    Joined:
    Dec 27, 2020
    Messages:
    16
    Likes Received:
    10
    It swings back with 1.5 watts into it and 25watts from Lenear with motor off my radio being new uniden pro 520XL only keys 1.5 watts with dummy load on meter a PDC600 I just checked my PDC meter, it has switch for pep and average, I'll run through more test tomorrow if not raining again
     
  14. Shadetree Mechanic

    Shadetree Mechanic 808 On The North Side of Dover

    Joined:
    Oct 23, 2017
    Messages:
    4,428
    Likes Received:
    6,842
    It seems strange that the dead key jumps up to 90w with the motor on. Maybe the mic is picking up the sound of the motor?
     
    ForestRunner98 likes this.
  15. 144inBama

    144inBama Sr. Member

    Joined:
    Apr 22, 2020
    Messages:
    512
    Likes Received:
    863
    What condition is your battery in? It may not be holding proper voltage in a static state, it's possible to have less than 10.5 VDC. and your vehicle will still crank. That would explain why there's such a big difference in output from one state to the other. Agree with the backwards swing theory, providing you're getting ample voltage and current, it's possible both are starving, depending on your setup.
     
    Eldorado828 likes this.

Share This Page

  • About Us

    The WorldwideDX Radio Forum was originally established in 2001. We pride ourselves on welcoming Radio Hobby enthusiasts of all types, while offering unbiased, informative, and friendly discussion among the members. We are working every day to make sure our community is the best Radio Hobbyist's site.
  • Like us on Facebook

  • Premium VIP Member

    The management works very hard to make sure the community is running the best software, best designs, and all the other bells and whistles. Care to buy us a beer? We'd really appreciate it!

    Donate to us!