Coax cable


#1

Need to add a couple N connectors for my tool bag since they switched to all the same connectors. What coax are in the NIFC kits now?
Thanks,
Onelick


#2

They are using N connectors for the coax and Anderson Pole connectors for the power supplies.


#3

I understand that. I worked with it this summer. I just forgot to take a picture of the coax, so I know which N connector to get. Please reread my question.
Thanks,
Onelick


#4

HA!!! So wrapped up with you asking about N connectors as I did not read the WHOLE message. I do not know what size of coax it is.


#6

If I remember correctly it is RG-213, hopefully not LMR-400.


#7

i’m not familiar with all the different kinds of coax. Just for my educational purposes, why not LMR-400?

Thanks for the info on the RG213.

Onelick


#8

Try calling the radio support group at NIFC


#9

LMR-400 uses an aluminum foil shield laid next to tinned copper wire for the shield and a solid copper center conductor… A knick or cut in the outer insulation causes moisture to enter the shield, corroding the tinning on the wire and oxidizing the aluminum foil. This corrosion of dissimilar metals causes a form of a diode to be created in the shield. This diode creates a mixer that will create inter-modulation products of the fundimental R.F. components present on the coax, creating interference. Also, the solid center conductor can work harden with use and break, rendering the coax useless. Not something desirable on NIFC radio kits that are in constant use and transportation. RG-213A/U has a shield with no dissimilar metals present, making it less susceptible to intermod generation, the stranded center conductor tolerates flexing a lot more than a solid center conductor, which means longer service life, especially important on NIFC boxes.


#10

Thanks for the education. We had some cows wander through one of our command repeater sites this year and pulled the coax out of the connector on the box. I didn’t have any extra connectors, but the other COMT did and we were able to do a temporary fix until we could get a new coax up to it. Which is the whole reason for my starting this thread. Thanks for all the help. I appreciate it.
Onelick


#11

That explains a lot. When I first saw the new kits this year I decided it was time to start carrying connectors and the cable prep tool and the crimper. Expensive as all get out, but worth it in the long run.


#12

Thank goodness that we are only dealing with VHF. Hope we keep these frequencies. RG213 VS LMR 400 on UHF over a 1/3 to 1/2 loss.


#13

We are dealing with both VHF and UHF. The command repeaters are VHF and the Logistics repeaters are UHF.