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LMR TIMES 400 OR LMR 240?

Stellasstillarat

Stellasstillarat

Active Member
Aug 14, 2014
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I'm currently using 120' of LMR 400. I'm happy with it except for one thing. my station is on wheels so I can move it between two rooms. The fact that it's not a flexible cable makes it impossible to move between rooms without having to unscrew the pl259 ever time I move it. if I don't unscrew it the 400 becomes twisted and I've alerted had to replace the pl259 because the constant twisting eventually ruined the solder connection. I was also using it (400) as jumpers. Thay were also giving me problems due to their ridget characteristics. I purchased LMR 240 to replace the jumpers. It's flexibility is much better. I would like to change the main 400 120' out to the 120' of the 240. I noticed no charge in the performance between the 240 and 400 jumpers, both perform excellent and there was no differance but I'm concerned that 120' of the 240 may affect my performance compaired to the 400. It's used for 11 meters and about 500 watts. I perfer the 240 but won't change out the 400 if there's a chance it will not perform as the 400. My antenna (a99) isn't as high up as it should be (12' off the ground) and cant afford to lessen any recive or transmitt due to swr or power lose that the thiner 240 may cause (if that indeed is the case) What you say?
 

I would say go for it. Here are approximate ratings on the coax you have. Looks like 500w is well within the limits of the 240. The diff in attenuation you prob' would never notice. Someone else could tell you what it translates to in S units. Here are the charts for them if you haven't seen them already which you prob' have:

Power rating and attenuation: http://www.universal-radio.com/catalog/cable/coaxperf.html

It looks like it would take 6db of attenuation to affect 1 s unit so to me, I'd never notice a .6db of attenuation.
 
Last edited:
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I tend to agree with hobie102. Keep us posted on your results if you make the change.

My Times Microwave LMR 400 works fine and I would expect the same with TM brand LMR 240.
 
At my old QTH I ran LMR 240 (150 ft) from shack to top of tower for my dipole. At the most I dumped 1kw into it with no problems for a short period. And before someone asks why 240, it was free along with 140 ft of LDF2-50 which I used for VHF.
You will not notice the difference for what you want to do.
 
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If it were me, and the 400 is in good condition, I would just do a jumper in the house for the 240 and be happy. Much cheaper that way, and I doubt you'll see any difference in performance.

73,
Brett
 
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hobie102 said:
I would say go for it. Here are approximate ratings on the coax you have. Looks like 500w is well within the limits of the 240. The diff in attenuation you prob' would never notice. Someone else could tell you what it translates to in S units. Here are the charts for them if you haven't seen them already which you prob' have:

Power rating and attenuation: http://www.universal-radio.com/catalog/cable/coaxperf.html

It looks like it would take 6db of attenuation to affect 1 s unit so to me, I'd never notice a .6db of attenuation.[/QUOTE. Thanks hobie. QUOTE]
hobie102 said:
I would say go for it. Here are approximate ratings on the coax you have. Looks like 500w is well within the limits of the 240. The diff in attenuation you prob' would never notice. Someone else could tell you what it translates to in S units. Here are the charts for them if you haven't seen them already which you prob' have:

Power rating and attenuation: http://www.universal-radio.com/catalog/cable/coaxperf.html

It looks like it would take 6db of attenuation to affect 1 s unit so to me, I'd never notice a .6db of attenuation.[/QUOT
Click to expand...
binrat said:
At my old QTH I ran LMR 240 (150 ft) from shack to top of tower for my dipole. At the most I dumped 1kw into it with no problems for a short period. And before someone asks why 240, it was free along with 140 ft of LDF2-50 which I used for VHF.
You will not notice the difference for what you want to do.
Click to expand...
binrat said:
At my old QTH I ran LMR 240 (150 ft) from shack to top of tower for my dipole. At the most I dumped 1kw into it with no problems for a short period. And before someone asks why 240, it was free along with 140 ft of LDF2-50 which I used for VHF.
You will not notice the difference for what you want to do.
Click to expand...
binrat said:
At my old QTH I ran LMR 240 (150 ft) from shack to top of tower for my dipole. At the most I dumped 1kw into it with no problems for a short period. And before someone asks why 240, it was free along with 140 ft of LDF2-50 which I used for VHF.
You will not notice the difference for what you want to do.
Click to expand...
When you write "
binrat said:
At my old QTH I ran LMR 240 (150 ft) from shack to top of tower for my dipole. At the most I dumped 1kw into it with no problems for a short period. And before someone asks why 240, it was free along with 140 ft of LDF2-50 which I used for VHF.
You will not notice the difference for what you want to do.
Click to expand...
binrat said:
At my old QTH I ran LMR 240 (150 ft) from shack to top of tower for my dipole. At the most I dumped 1kw into it with no problems for a short period. And before someone asks why 240, it was free along with 140 ft of LDF2-50 which I used for VHF.
You will not notice the difference for what you want to do.
Click to expand...
binrat said:
At my old QTH I ran LMR 240 (150 ft) from shack to top of tower for my dipole. At the most I dumped 1kw into it with no problems for a short period. And before someone asks why 240, it was free along with 140 ft of LDF2-50 which I used for VHF.
You will not notice the difference for what you want to do.
Click to expand...
binrat said:
At my old QTH I ran LMR 240 (150 ft) from shack to top of tower for my dipole. At the most I dumped 1kw into it with no problems for a short period. And before someone asks why 240, it was free along with 140 ft of LDF2-50 which I used for VHF.
You will not notice the difference for what you want to do.
Click to expand...
binrat said:
At my old QTH I ran LMR 240 (150 ft) from shack to top of tower for my dipole. At the most I dumped 1kw into it with no problems for a short period. And before someone asks why 240, it was free along with 140 ft of LDF2-50 which I used for VHF.
You will not notice the difference for what you want to do.
Click to expand...
Click to expand...
binrat said:
At my old QTH I ran LMR 240 (150 ft) from shack to top of tower for my dipole. At the most I dumped 1kw into it with no problems for a short period. And before someone asks why 240, it was free along with 140 ft of LDF2-50 which I used for VHF.
You will not notice the difference for what you want to do.
Click to expand...
2RT307 said:
If it were me, and the 400 is in good condition, I would just do a jumper in the house for the 240 and be happy. Much cheaper that way, and I doubt you'll see any difference in performance.

73,
Brett
Click to expand...
I actually concidered this but, thought the difference in size between the 240 and 400 would make this a no no. If a few more people could whaigh in on this. A barrel connector, 240 to type he 400, will this work?
 
Stellasstillarat said:
I actually concidered this but, thought the difference in size between the 240 and 400 would make this a no no. If a few more people could whaigh in on this. A barrel connector, 240 to type he 400, will this work?
Click to expand...
This will work if the lines are good, and you'll never notice any difference there may be.

If the barrel connector is outside...make sure it is well protected from the weather and water.
 
LMR 240 is good. I ran the ultraflex version of it mobile. Low loss, good stuff. Better than RG8X IMO.
 
UOTE="Marconi, post: 502848, member: 903"]This will work if the lines are good, and you'll never notice any difference there may be.

If the barrel connector is outside...make sure it is well protected from the weather and water.[/QUOTE]
Thanks Marconi. I hold your advice in high regard. Thanks to everyone who answered my questions. Y'all just saved me over $100. Not to mention the hassle it would take to exchange the pl259 at the antenna's end. I can get the barrel inside or out. inside is the way I'll go. Happy bird day to y'all. Tryptophan coma!!!! Yahooooooo!
 
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Stellasstillarat said:
I actually concidered this but, thought the difference in size between the 240 and 400 would make this a no no. If a few more people could whaigh in on this. A barrel connector, 240 to type he 400, will this work?
Click to expand...

Makes no difference what the size of the cable is. Just don't mix impedances except in very special cases. I run LDF-4 heliax cable with RG-8 type pigtails on each end for flexibility and then some RG-8X mini foam in the shack between switches etc. for even better flexibility and convenience and it makes no difference at all.
 
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I put up 100ft of some Andrew lmr240 for a friend of mine and it's been about a year now in the FL weather, he runs up to 1kw through it and has never had an issue. It's good coax and will work well. Times microwave is the same stuff, different name and maybe a different outer sheathing but the insides are the same. And yes it's a bit more flexible than the lmr400. Go for it and have fun. God bless.
 
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Stellasstillarat said:
I actually concidered this but, thought the difference in size between the 240 and 400 would make this a no no.
Click to expand...

It doesn't matter, the adapter will ensure that the ratio between the outer of the centre conductor and the inner of the outer remain as they need to be to have a 50 Ohm impedance going from one to the other. Commercial repeater installations go from 2" or wider hardline coax down to RG213 size patch cables both at the antenna end and where they enter the building.
 

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