Reports of signal fading during a QSO.

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  • Updated 2 months ago
  I have a new-to-me Flex 6500 and have received several comments about my signal fading during a QSO.  The PowerSDR RF power meter shows a constant power during the QSO.  How can I determine if the radio is working correctly?  I have a limited period to request correction from the seller.

The radio is Flex 6500 SN 0316-5064-6500-8299.  HW version is v3.1.7.138 with options None.  Software is SmartSDR 3.17.  PS is Astron RS-35M.  I am using a Dell SPS 8700 16GB with Win10.  I am also using FLDIGI 4.1.08.

Thurman Irving N5SI
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Thurman Irving

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Posted 2 months ago

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Photo of Mark - WS7M

Mark - WS7M

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Are you sure its simply not the band conditions?  They are not great these days and QSB is a very real thing in most QSOs
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Neil D Friedman N3DF

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Band, time of day and location for each fading contact?
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Dean Davidson

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You need a meter between antenna and radio to determine if your power is dropping while talking . Dont ever depend on just the meter on the radio.
What mic are you using?
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Bill W2PKY

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External power meter will put your concerns to rest.
Borrow one from a friend if you do not have one.
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Dean Davidson

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NEIL has a good point Band conditions are not real good here lately.
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Michael Walker, Employee

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The only way to test this is to watch the RF power out with a calibrated watt meter and a good dummy load.    Band conditions and possible antenna health can contribute to signal reports like you are hearing.

Another data point would be to have a local (meaning 5 miles or so) listen to you.  But, again, it would be subject to the above test if they also heard a signal fade.

My other comment is that could it be your mic position when compared to your mouth?  Long QSO's can result and the mic moving further away from your mouth.

Those are just some ideas.


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WW1SS - Steve

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There has been lots of QSB on signals lately. Band conditions are horrible.
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Paul - K6HR

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You might also consider listening to your signal via one of the remote receivers on the internet and see if it's just conditions. Let us know how it performs on the dummy load.
Photo of Neal Pollack, N6YFM

Neal Pollack, N6YFM

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Band Conditions? I have not seen anything lately that resembles usable band conditions. Try talking with someone in your local area, like 5 to 7 miles away.
Else, launch a kickstarter go fund me campaign, and buy us some sunspots....
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Bob N0IS

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A monitor scope in the transmit line will always let you know what it going on with your transmit signal.

Bob, N0IS

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David Decoons wo2x, Elmer

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One other thing to check is if the processor is on or not. Recommended to have processor on and in normal setting. This will help keep tx level more consistent.

Dave wo2x
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To monitor your output RF strength, a low-tech solutions is a field strength meter using a 1N34A diode, some caps and a VTVM for read out.

Tim - k3Tim