[TowerTalk] Loss in Connectors

[Steve Gehring]

Hi Steve,

In my system design of SONET OC-48 and OC-192 telco backbone rings last 
year, we used the figure of -0.08 dB for each fusion splice of single mode 
fibers at a frequency of 1550 nanometers (nm).  We also figured around -0.1 
dB for the other clean, polished, and mechanically sound "non-fusion" type 
connections used within buildings, etc.  These were conservative figures, 
too.  After several 5.5 KM reels, the splices added up...slowly.  Now, I 
just can't believe that the connectors at the freq's we deal with (HF RF 
instead of light) could even come near the attenuation of connectors at 
light.  This is a supposition on my part, but the data mentioned in the 
relayed "senior project" post seem to point this out.

I believe Mr. Tom also pointed this out...

As I believe you said, and the "senior project" made mention of, let's make 
sure our RF connections are clean, mechanically sound, and 
weatherproofed!  BTW, water and contaminant ingress in fiber splice cases 
(just like rf connectors and cables), causes large losses.  In many 
regards, RF and light transmission lines are alike.

Here's that measured connector loss link again:

http://lists.contesting.com/_cq-contest/199609/0345.html

Also, I look forward to meeting you at a future WWDXA meeting.  I'm in the 
Bothell area now, and would sure like to make a mtg soon.

Interesting topic!

73 de Steve, KZ9G

At 12:09 PM 1/21/2002 -0500, you wrote:

>In a message dated 1/21/02 5:19:31 AM Pacific Standard Time, w8ji@akorn.net
>writes:
>
> > Loss is the least of our worries with connectors, by far the real
> >  concerns are over-heating, voltage rating, and (if on VHF or higher)
> >  SWR.
>
>     To that list I would add "weatherproofing" - more connector problems are
>attributable to poor weatherproofing than any other failure mode.
>
>     The 0.2 dB is a figure I cited that the Andrew Company uses in their
>cable loss calculator program.
>
>Cheers,
>Steve     K7LXC
>Tower Tech
>
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Where do you get ICE bandpass filters & beverage matching boxes?  The
same place that pays for the hosting of this list:  The eHam Store.
Order online at http://store.eham.net.
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