Hello Bob,
You asked a good question, but you are not going to like the answer.
Good and cheap does not walk hand in hand.

The reason why the established companies are head and shoulders above the generic equivelent is because the established companies has a much higher quality standard.

LMR 400 is a two edge sword.
Yes it is good, but it is also slightly more cost and a lot less durable then other types of cable.

The main use for LMR 400 is the higher ranges of UHF due to the fact that it has a lower loss rate.

A few things to remember, its center conductor is 10 gauge / not 12.
Its shield is foil - braid, not copper conductor. Its dielectric is foam not poly.

You have to buy special connectors, you aren't going to screw a PL connector on it and you can't solder it.
You have to have crimp pliers - and the $2.50 or more PL connectors to use it.

The foam dielectric is hygroscopic - it attracts water and it's life span is maybe 10 years. You aren't going to put it up and walk away and 30 years later still be using it - because once the water gets inside of it, it is ruined.

The outer jacket is very fragile, if it gets a knick or gets damaged, you are going to have to either splice it or replace it.

If your work involves UHF - your needs would be better off met with Hardline then with LMR 400. There are radio towers out there with hardline that is 40 years old that is still in service.

Often times, if you know the right person, they will sell you used hardline for a lot less money then new LMR 400.. After all, unless they are going to build a repeater - they probably don't have any use for it.

I hope this is not information over load.

When using generic LMR 400 - you want to make sure to have it sweep tested before you put it up. The Chinese aren't real particular what they sell, and most times the deal is that there is a bad spot somewhere in the coax and that is the reason why they wholesale it with no name on it.

"Channel Jumper" wrote in message
...

LMR 400 is a two edge sword.
Yes it is good, but it is also slightly more cost and a lot less durable
then other types of cable.

The main use for LMR 400 is the higher ranges of UHF due to the fact
that it has a lower loss rate.

A few things to remember, its center conductor is 10 gauge / not 12.
Its shield is foil - braid, not copper conductor. Its dielectric is
foam not poly.

You have to buy special connectors, you aren't going to screw a PL
connector on it and you can't solder it.
You have to have crimp pliers - and the $2.50 or more PL connectors to
use it.

LMR400 has foil, but it also has about a 95% braided shield. It is as easy
to solder to as any other rg8 type of coax with a braded shield. A standard
PL259 fits it just fine. Atleast all the ones I have used do. If using
some N type connectors the center pin needs to be specified as the
lmr400/9913 type due to the larger center conductor.

The dielectric is fine also. It is no worse than any other coax. It is not
like the origionaal 9913 coax that was a hollow tube that could fill with
water. I had 2 runs of that up about 50 feet to the antennas and did not
have a water problem in about 10 years. It was still dry when I took it
down for a move.


Still not sure about what you are calling the 'generic' coax. There is some
sold by TheWireMan with his brand. He does not make it, but buys it from
another company. That seems to be as good as any other of the same type
going on my sweeping two 100 foot rolls of the LMR 400 type and 100 feet of
a coax of a differant type from him from about 30 to 1000 MHz. Same as the
Davis Bury Flex. That Bury Flex is tougher to work with than some.

One indication the coax is not very good quality is if the braid is less
than about 90%. The beter ones should be atleast 95%. Most of the loss in
coax is in the center conductor and then the braid. That is up to around
1000 MHZ. But after that, most are not going to use coax anyway.

在 2013å¹´3月6日星期三UTC+8下å�ˆ9æ—¶33分11ç§’ï ¼ŒChannel Jumper写é�“：
'Bob[_32_ Wrote:


When using generic LMR 400 - you want to make sure to have it sweep

tested before you put it up. The Chinese aren't real particular what

they sell, and most times the deal is that there is a bad spot somewhere

in the coax and that is the reason why they wholesale it with no name on

it.



Channel Jumper



The retrun loss can be better than 26dB from 5Mhz to 3G,we supply CNT400 for ANDREW.