On 11/07/2015 17:12, Terry Casey wrote:
In article ,
says...


It's a commonly held view given that feeder losses are so much greater at
UHF, but it's wrong.

How about reading the manufacturers tables?
eg: URM43. 100MHz loss 13dB/100m
600MHz 34

URM67 50 MHz 4.5
800 MHz 18

Note sure if that adds anything... he just said that the feeder losses
are higher at UHF, but that does not necessarily mean that termination
losses are as well.

There are two issues here and it important to address them both. The
original, before it was selectively quoted, was:

In article ,
says...

It's a commonly held view given that feeder losses are so much greater
at UHF, but it's wrong.

Even if it's open circuit at DC there will still be a few picofarads
of capacitance, and capacitive reactance decreases as the frequency
increases.

The first part is very obviously wrong, as has been already been said.

Its not thought ;-) everyone keeps misreading it!

If one assembles the bits it effectively says:

"I'd expect far greater losses from an un-soldered joint at Band V"

To which Graham in effect replied:

"It's a commonly held view, but it's wrong."

What seems to have got everyone's knickers in a twist is the added comment

" *given* that feeder losses are so much greater at UHF,"

(my emphasis on "given") - i.e. he is acknowledging that the feeder
looses will be much higher, but this is a point unrelated to the effect
of frequency on poor connections (which will better "jump" small open
circuits due to the lower reactance of the capacitor formed)





--
Cheers,

John.

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