Jumper from LMR-400 to Mobile Base radio

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N5JMC

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I ran 60 ft of LMR-400 from the area in my living room where my mobile is setup as a base to a wall plate and up the wall into the attic to the antenna. I heard it was stiff but man it's really stiff.

I am looking for something that I can use with a coupler from the lmr400 to my mobile that will make the curves better, especially connecting to the back of the mobile. I'd like to use this starting a little after the lmr400 comes out of the wall. That way it can turn the angle of the wall and run to the radio better. I don't want to buy something that will have enough loss that will defeat the lmr400 I just ran.

I left the subject more generic but mainly interested in how flexible is the lmr400 ultra flex? Would it do the job. Can anyone tell me what it's comparable to in terms of thickness and flex/curve? If I went with 400 ultra flex, would I loose that much with it and a coupler? Also, is a coupler the best thing or is there something else like a box or something to buy to run the lmr400 to and then the ultraflex or whatever I go with to the radio?

If you list a recommendation please also list what you think my loss will be with adding what you recommend with a coupler.


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mmckenna

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LMR-400 Ultra Flex is a bit better, but it's still a heavy cable. While flexibility is important, so is the weight on the radio connector.
Ideally you'd use mating connectors rather than a coupler. Since you'll either need to make your own cable or order one pre-terminated, just get the correct connectors on the end to match.

You didn't say how long the run is from the wall to your radio. I understand the desire to reduce feed line losses, but you need to consider something smaller than LMR-400. There are some good options out there, if the run is reasonable. LMR-240 is good cable and easier to run. LMR-195, even RG-58 can work well.
 

N5JMC

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It would be about 15-18 ft. I may even continue the lmr400 behind the couch so then I'd just need like 8 feet maybe less.


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mmckenna

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It would be about 15-18 ft. I may even continue the lmr400 behind the couch so then I'd just need like 8 feet maybe less.
That's exactly what I'd do, if I couldn't bring the coax down the wall directly behind the radio. A few feet of RG-58 isn't going to be noticeable, and the difference in losses between a few feet of RG-58 and a few feet of LMR-400 are not going to be noticeable.
 

N5JMC

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LMR-400 Ultraflex vs RG213

Does anyone know which is more flexible? I have LRM-400 running from living room where I use my mobile into the wall up to the attic to my antenna. I need something more flexible to hook to my radio. Length will be 5 ft if I leave LMR-400 behind couch and connect jumper there or 18 ft if I connect it in the wall so the more flexible is running the wall. I can buy RG213 here local for a decent price. But I'm wondering if LMR-400 Ultraflex is as flexible or what and if I should go with it to not loose a lot by connecting a jumber.
 

cmdrwill

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RG213 is more flexible. Flexing LMR400 type cables can cause the shield foil and or shield failure. Or maybe 'excess flexing' ,been there and had to find the bad cable.
 

krokus

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That's exactly what I'd do, if I couldn't bring the coax down the wall directly behind the radio. A few feet of RG-58 isn't going to be noticeable, and the difference in losses between a few feet of RG-58 and a few feet of LMR-400 are not going to be noticeable.
Unless you are doing microwave operations, or high power, I agree with the RG-58.

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N5JMC

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LMR-400 Ultra Flex is a bit better, but it's still a heavy cable. While flexibility is important, so is the weight on the radio connector.
Ideally you'd use mating connectors rather than a coupler. Since you'll either need to make your own cable or order one pre-terminated, just get the correct connectors on the end to match.

You didn't say how long the run is from the wall to your radio. I understand the desire to reduce feed line losses, but you need to consider something smaller than LMR-400. There are some good options out there, if the run is reasonable. LMR-240 is good cable and easier to run. LMR-195, even RG-58 can work well.
Any idea on some good sites to order custom cable with mating connectors?
 

AK9R

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Cable Xperts is another on-line source of custom RF cables. They can make cables for you using Andrew Cinta CNT-240 cable which is similar to Times Microwave LMR240.
 
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