Nate30 - You are apparently a newbie when it comes to QR 540 cable OR you didnt take the time to fully read my comment. Here's to your education.
The older qr540 pin fittings (the ones with the metal radiation sleeves on the pin portion of the fitting) ,first came out when the new QR cable hit the market. At the time, some/most systems were upgrading from 330Mhz to 550MHz and then later from 550MHz to 750Mhz. These older style (all metal) connectors worked great at these frequencies, no problems. It wasn't until those MSO's started upgrading to 860/870Mhz (1999-2000) that the problem with these connectors was discovered. The older connectors caused suckouts beyond 790MHz. If you were sweeping QR cable back then (@860MHz) you would have seen the problem.
The connectors were looked at tested by the various connector manufacturers and commscope as well. Without any finger pointing, It was determined that the QR connectors needed redesigned in order to pass the higher frequencies. A new connector was made (the one with a plastic insert) and could now be installed to correct the problem (2002). The problem was fixed and new connectors were shipped out for new builds and upgrades, only the problem still remained. There were thousands of miles of plant built during this time using the older style connectors. I don't know of any major MSO that had a complete retrofit project to remove all of the defective connectors. After all, their plant works fine out to 750MHz, why fix it. The problem only showed up in those systems that upgraded to 860MHz or 1GHZ and had the older connectors.
Now fastforward to today. Guys are going out and sweeping thru QR cable that may or may not have had the old connectors removed during the rebuild. Problem is that you cant tell a newer style connector from the older one. Hence the problem that Ned is having. Which brings me to your comment.
"How can a old connector not work with higher freqs? " Fittings are available at different leves of quality and abuility to pass signal. "sweep rating".
You can end up with a bad fitting from a number of variables like qualiy of installation , weather..........any dulling of color and I would change it right off the bat.
"How can a old connector not work with higher freqs? I think I have explained this well enough. I won't even get into isSues like (P3 on P1, FEED THRU connectorS, PYRAMID, AMPHENOL, PPC etc...)
Fittings are available at different leves of quality and abuility to pass signal. "sweep rating". No, you are wrong here. Fittings are not available at different levels of quality and ability to pass signal "sweep rating" . Are you referring to insertion loss? nominal...
You can end up with a bad fitting from a number of variables like qualiy of installation , weather..........any dulling of color and I would change it right off the bat.
Just to clarify, the fitting isn't bad, the splicing is. The fitting will not go bad on its own it it was properly installed (clean, tight, dry, proper length center cond...). Its the quality of the splicing that will determine whether the connector should be replaced (i.e. loose, water ingress, stripped back nut, or wrong type).
any dulling of color and I would change it right off the bat. If sweepers were to live by this rule, we'd never make any money. (Aluminum, Air, Water and Sun light...enough said)
And just as a side note, to complicate this QR connector issue even more is the fact that the older connectors don't always cause a suckout at the high end. Temperature and the quality of installation are the two major factors that will cause an older connector to pass or fail. Ironically, if the splicer had a worn QR coring tool and that tool removed a little of the dialectric from the inside of the outer conductor while it was spinning around during the coring process, then the metal portion of the qr fitting will make contact enough to allow a good ground/bond with the cable. If this happens the connector will work fine up to at least 1GHz, with no suckouts. Providing the rest of the splice job is good.
In hotter temperatures, more of the older connectors will work or can be made to work by tightening. In colder temps the metal inside the connector shrinks enough to loosen the bond with the outer conductor and thus more suckouts. BTW this is few and far between and I don't condone tightening the connector to remove the suckout as it is likely to come back when temperatures are different. When a suckout is found, the old style connector should be replaced with a new one, (you have to pull the splice apart anyway to troubleshoot)
If you don't have a new style connector with you and you are up on a pole in rear easment and you have to remove a suckout then there is a way to make the old style connector work....
Have a nice day!!
Kris
p.s. any time bro...
Re: Sweep Issues
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