Has anyone ever had a problem of fluctuating output power?

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  • Updated 7 months ago
I have a 6300 that works as it should most of the time and then the output power begins to do wierd things. I am using version 1.11.12 software. I can set the Tune power to, let's say, 60 watts. I can hit the Tune button most if the time and get 60 watts, but other times, I might get 23 watts that will then go to 40 watts and then 60 watts, or it may actually go down from 40 and then back up to 60. It doesn't appear to be temperature related and the SWR is 1.06 to 1. Voltage is 13.4 and drops to 13.2. I haven't read anything of this problems and thought some of you might have had this problem and could give advice before I send it on for repairs.
I am going to up the voltage to see if this helps.
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Roger Miller

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Posted 7 months ago

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Larry - W8LLL

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I would recommend one of the apps that read radio voltage like frstack or k9dur monitor if your not already to make sure your radio is getting steady DC voltage. I have had to adjust the power pole connectors on the power cord to add a little more spring to them as the were doing what you describe. Voltage at 13.2 to 13.4 is to low in my opinion.
(Edited)
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Zack Schindler

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This link shows how to adjust the output power on an Astron PS.
http://www.repeater-builder.com/astron/voltage-adjust/voltage-adjust.html

(Edited)
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Rick Hadley - W0FG

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13.2-13.4v is way too low.  Keep the input to the radio at 14.1-14.5 and monitor it with DDutil or similar.
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Bill -VA3WTB

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Yes. the power to the radio is not steady, at the very least you should be at 13.8v on transmit.
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Jon - KF2E

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Do yourself a favor and only do tests like this into a dummy load. Also, what is the rating of your power supply? Voltage being a little low shouldn't cause power to fluctuate, it could cause low power but as long as the voltage remains constant so should the power. Voltage fluctuating will cause power fluctuations and if your power supply is under rated or under performing it could be the cause.

Jon...kf2e
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Roger Miller

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Have tried two different Astron 70 amp supplies and the Smartsdr Stacking meter shows no fluctuating of voltage.
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Jon - KF2E

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Then you should definitely try a dummy load next.

Jon...kf2e
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Roger Miller

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That is next with an adjustable voltage power supply. Thanks for your input.
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Larry - W8LLL

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The astron 70's are adjustable on the inside.
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Roger Miller

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Neighbor has one adjustable. If that helps, I will go inside mine and up the voltage. Never had a problem with other radios for the 20 years I've had this supply.
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Larry - W8LLL

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Like others have said your lower voltage should have nothing to do with the voltage changing, The power pole connectors can cause the problem your having. I even seen one thread where someones antenna tuner would fail before it acquired its tune and it turned out to be power poles not connecting properly. Besides bending the metal to add more spring in the connector I have used a little de oxit spray on them. of course this may or may not be your issue. I have both of my astron 70's to where they idle at 14.3 vdc and on radio full power on TX they drop to 14.0 vdc, that provides about 105 watts output.
(Edited)
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Justin - KL2D

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I had a similar problem, it was voltage drop across my power distribution system. I turned up the voltage on the power supply a little bit so I had 14.6V at the posts on the back of the supply, which translated to a reading of 13.85 at the radio using K9DUR's meters. I am having way more stable output power now. I originally had 13.85V at the posts on the back of the supply, as from the factory, and was only seeing 13.11V at the radio.

Should mention, I was running power from the supply to a rigrunner 4010S and then to the radio. 

Hope that helps,

73

Justin
KL2D
(Edited)
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Roger Miller

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Thanks Justin.
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Roger Miller

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What would be the maximum voltage you would have on the Frstack meter?  Would 14.0 be too much if it drops to 13.8 on full power output on key down?