[TowerTalk] Coax Impact on Receive Performance

Ken Bauer ken.bauer at mac.com
Tue Mar 23 14:27:07 EDT 2021


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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