FlightAware Discussions

What a difference 20' of USB cable makes

Now that the outside air temps have dropped below 90°F I was able to enter my attic to relocate a fan cooled RPi 4 from my comm closet to the attic. I eliminated 20’ of high quality USB3 cable by connecting the FA blue dongle directly to the RPi. So far the CPU temp hovers around 65°C.
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USB extension is the worse idea. Seconded only by putting the electronics in attic.

I don’t get why people are scared of plain old coaxial cable extension… especially when you can buy it with connectors installed.

I’m in a condo where no outside antennas are allowed. Otherwise I’d put everything on a chimney mounted mast.

BTW my attic has many electronic devices - ozone generator, air filter, air handler, smoke detector and security system sensors.

Not necessarily, it depends on the quality

I am using a 2 Meter USB extension and it gives me exactly the performance as i would plug in the stick directly into the raspberry port.

But i also have an extension which decreases performance of the receiver by 30%

I didn’t say to put it outside. I was wondering why you choose initially to use 20’ of USB cable instead of 20’ of coax.
That’s all.

He is talking about 7 meters…

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People choose USB extensions for a few reasons:

  1. Heat control - less heat transfer to/from the radio
  2. Eliminate signal loss / So long as the cable isn’t dropping packets, using a USB extension will outperform lossy Coax/LMR IE, zero signal attenuation since it’s already been processed
  3. Maintains ability to perch antenna in a higher area and keep the SBC accessible and/or out of the weather.
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None of those are true (for the above case), but whatever…

You’re talking about USB extension in general:

USB extension is the worse idea

In some cases a USB extension makes more sense than a coax if it comes to the point where to put it. Through some windows a USB cable can be put through easier than a coax cable.
I would always test any cable compared to a shorter one before i mount it somewhere.

A buddy of mine has the same issue.
He put up a nice “flag pole”, as flags are allowed where he lives.
Its a DPD antenna with an American flag hanging on it mounted on an eve with a flag pole mount

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I thought about that, but there was no way to run a cable shorter than 50’.
If a cable was spotted during an inspection, I’d have to remove it.

Do they inspect it every week? :rofl:

Yes, exterior inspection is every week. I know, I’m an officer on the board.

Take everyone in the board out for a pint of beer then…
New meaning to the phrase “beer goggles”.

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USB isn’t THAT bad…

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Dang, that stinks. Stuff like that around here is just inspected at installation and never checked again.

That can become quite expensive immediately :smiley:

Yeah, but we all have to suffer for this hobby! :airplane:

Right now I am looking at a cart on Uptronics that says 86.24 UK pounds and I wonder if I should hit the buy button…

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And? Decision made after eight hours thinking about it?

Noo, I had slept over it and it’s still in the cart :rofl:

However, I did a scan this morning to see if I really need it or just want it. Still not sure…

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I just decided that I need a Sysmocom cavity filter.
Next month I’m sure I need something else :crazy_face:

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