[QuadList] Patch cables/bays (Was ...some useful info fromBAVC...)

[COURYHOUSE at aol.com]

no.... it is analog...  it was a  gift...  
 
details to follow....
 
 
Ed!
 
 
 
 
In a message dated 7/13/2009 1:53:51 P.M. US Mountain Standard Time,  
dwnorwood at embarqmail.com writes:

-----  Original Message ----- 
From: Ted  Langdell

>>SNIP<<

So, you need to know whether your  panel has:

WECO or RCA
75 ohm or 50 ohm (You need 75 for  video)
Terminating or non-terminating
Normaled or single jack  "straight-through"
--------------------------------------

Ted and  Ed........

It is true that no matter what the application, WECO and RCA  patch 
connectors should never be intermixed due to the physical  differences.

But.......if what Ed is dealing with is composite video,  then the 75 ohm 
situation needs some clarification.  The two  connector styles each have a 
characteristic impedance (which is what gives  them the slightly different 
dimensions).  WECO is 75 ohms and RCA is  50 ohms.  However, at baseband 
video frequencies, that's not really  an issue.  There were many thousands 
of 
RCA patch panels used with 75  ohm video systems.  If you examine the part 
numbers, you'll see that  the 50 ohm RCA normalling jacks are available 
with 
either 50 or 75 ohm  internal terminating resistors.  That's the important 
part as you do  not want to use normalling jacks (in either style) with 50 
ohm internal  terminations.  This situation is similar to the use of BNC  
connectors, virtually all of which were 50 ohms for many years.  At  
baseband 
video frequencies (<10MHz), it doesn't matter electrically,  only 
physically.

Now....if we're talking about digital patching, that's  a different ball 
game, but I don't think that's what Ed is  doing.

Don



**************Looking for love this summer? Find it now on AOL Personals. 
(http://personals.aol.com/?ncid=emlcntuslove00000003)
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://quadvideotapegroup.com/pipermail/quadlist_quadvideotapegroup.com/attachments/20090713/fe19c3c4/attachment-0004.html>