Cable adapter loss?

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lawnmowerman
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Cable adapter loss?

Post by lawnmowerman »

How much do adapters contribute to signal loss? I'm trying to figure out if it's worth changing my cables from the Mofi to the external antennas, locked onto B4. I have 25' of LMR 240, specifically https://www.amazon.com/gp/product/B00QZEQ5EA/. The nice thing is it has an SMA male connection built in on one end, so that it connects directly to the Mofi without an adapter; whereas the LMR 400 I already have (I have a couple 30' lengths lying around) does not, both ends are N male, and so requires an adapter. Based on what I've found online, all other things being equal, I'd maybe gain 1-2 dB going from 25' LMR 240 to 30' LMR 400, though that doesn't account for adapters. It'll take a little work to switch the cables, so I want to make sure it's worth it before going through the trouble, you know? Thanks!
gscheb
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Re: Cable adapter loss?

Post by gscheb »

lawnmowerman
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Re: Cable adapter loss?

Post by lawnmowerman »

Thanks for the link. So using that, yes it's about a 1.2 dB difference between LMR 240 @ 25' and LMR 400 @ 30'. Under Product Performance Parameters, it says "Typical Connector Loss = 0.1 dB/pair," so does that mean the adapters don't make much difference?

To switch from 240 to 400 means using N-SMA adapter for the cable to Mofi connection. So I guess my main question is would I end up losing what I gain from switching from 240 to 400, if the the 400 requires the adapter? Like, is it a wash at that point?
gscheb
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Re: Cable adapter loss?

Post by gscheb »

Well as always it depends.
Yes looks like it is 1,2 db difference in loss. But if that extra length allows you to go up another 5 foot might gain another 3-5 db from antenna reception. Have seen this happen sometimes raising or lowering your antenna just few feet can change things.
Personally have never seen any losses in connectors without wire leads on them.
Like these here don't even see a difference when using them?
https://www.amazon.com/gp/product/B074M ... UTF8&psc=1

But something like this have seen a difference before depending on how long the length is.
https://www.amazon.com/Saide-Electronic ... 876&sr=8-2
lawnmowerman
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Re: Cable adapter loss?

Post by lawnmowerman »

gscheb wrote: Fri Sep 18, 2020 2:23 pm Well as always it depends
Yep, so many variables. It drives me a little crazy sometimes haha... Seems like whenever I change one thing, I inadvertently change something else.
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