Low power update

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  • Updated 3 years ago
I got my rig back yesterday from  the excellent Flex service centre in Germany and there was nothing out of calibration to cause my low-ish power readings when the power slider is set to full. Even so, it is nice to know that my rig is 100% okay.

Tanks again to Norbert and Flex.
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DrTeeth

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Posted 3 years ago

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Jim Gilliam

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Most incorrect power readinsg are due to RF on the outside of the coax. It might help to put an isolator at the antenna port (ferrites over the coax). Also if you are using coax to feed your antenna, a BALUN could help. RF in the shack is the bane of many amateurs. Putting ferrites on the earth lead would not be a good idea as it would impede the flow of RF currents to ground.

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DrTeeth

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Hi Jim,

I do have RF issues here, briefly (as already mentioned in a current thread) my desktop loses its Ethernet connection when I Tx on full power. The low power readings were not that bad, but had the rig checked out by the Flex European service centre. I have plaved 9 clip-on type 31 ferrites at the feed point and will be placing many more on leads in the shack.
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Rob Fissel

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Guy, are you using STP or UTP ethernet cable? Flex reccomends unshielded twisted pair, as I assume that the shield on STP will reradiate RF. I had similar issues in the past with long ethernet runs from the router to additional access points in the house. Replacing with UTP and clamp on ferrites on both ends resolved this issue. 
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DrTeeth

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Rob, the problem occurs if the shielding is connecting at both ends. I did start a recent thread asking about using CAT 6 cable as I had heard that is was very good to have in the shack. There was a long chat about the pros and cons to the shielding issue. I have not got a clue as to what cables I have other than it being CAT 5e.

I shall see if I can check but may order some new cables as that would be much easier than crawling around in the shack. Thanks for the info.
(Edited)
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Rob Fissel

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Yeah, I'd get away from shielded twisted pair for sure, and go with unshielded twisted pair. Also, clamp on ferrites will also help!
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Rob Fissel

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Separate but related story - 30 meter CW at 200 watts was enough to blow out my ONT box on the outside of the house that brought fiber from the pole, and distributed internet via Ethernet. The thing had issues at 100 watts where I would have to reset it to get internet connectivity restored. When I went QRO, first TX, and the box just went kaput. Lots of ferrites on the UTP CAT5, and replaced the plastic case enclosed ONT with one inside an aluminum enclosure - no more problems!