[TowerTalk] Coax Impact on Receive Performance

[Jim Miller]

In my opinion the difference between connected and disconnected of only 2db
shows that you are marginal and likely impacting your RX performance.

stay safe!

jim ab3cv






On Tue, Mar 23, 2021 at 2:27 PM Ken Bauer via TowerTalk <
towertalk at contesting.com> wrote:

> Just to check my thinking, I thought I would consult the experts here …
>
> I have about 350’ of LMR400 equivalent running to a Spiderbeam. When
> rotated to A25RU on 20m the other day my Flex 6600 showed the noise floor
> averaging -132 dbi showing as S1.5. A25RU would peak about 6db over noise
> the noise level.
>
> I figure on receive, coax loss will reduce both the signal and the noise
> equally, and that the coax has *no* impact on receive performance *unless*
> the loss pushes me below the receiver noise floor. If I disconnect the
> antenna, the Flex shows the noise floor averaging -134 dbi.
>
> Of course spending $$ and putting in good hardline will give me more
> transmit watts to the antenna, but will it help me hear better in this
> case? I’m thinking not ...
>
> Thoughts?
>
> Thanks in advance,
> Ken WC6Y
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