Is LMR-400 good enough for my new station?

[Doodad]

I understand that LMR 400 is a quality coax and convenient as well. I only want to buy coax once so I thought Id ask if it will work with my set-up or do I need to upgrade.

Be aware that I have read Runaway's post but our parameters are quite a bit different.

Selection facts:

1. Run will be approx 150'
2. Power will consists of a 12 tube Elkin w/approx 1000 watts pep
3. May also be asked to work with a 2x4 worldwide volted to approx 1500-1700 watts pep

Any help is appreciated

Dan

[drdx]

That should work fine, but I'm sure someone will say LMR600 or something, but anything bigger will need different connectors and drive up the cost. I don't know what your antenna plans are, but if you are running a beam or something that requires more than one run, consider a remote coax switch like an ameritron or something so you only have to buy one run of the 150 ft. Make sure it is real Times cable and not some knock-off as I've heard that the off brand versions lack a little to be desired. I get mine locally at tx towers and it runs $1 a foot. -drdx

[linx]

As doc said, you'll be fine! LMR 400 is excellent coax. I recently had a thread going asking where the best place to buy it. Pro151 recommended a guy from eBay. I think that guy sells True TM LMR 400 for about $.50/c a ft without connectors. That's good to me, b/c I'd rather put my own connectors on to know it's done right, and done with high quality connectors.

Here's the thread I had started with folks recommending where to buy: [Please login or register to view this link]

[THE WATCHMAN]

YES :D

[Midlander]

LMR-400 is what you want. You will have no problems with that cable. Just make sure it's the real stuff that says Times Microwave on it. if you don't see that on the cable, don't buy it.

They make two basic kinds. Ultraflex, and non flex type. Ultraflex costs more and has a softer rubber coating, but it bends much easier. The other is much stiffer and less prone to bending, great for outside.

[slydog]

LMR-400 or 9913 would do the trick.

[Doodad]

Been researching the heck out of coax and its loss characteristics. Have to be careful and not get carried away looking for the elusive "Best". It would be real easy to go to a loss chart and pick the coax with the lowest loss. Living in the real world and working for a living, I'll have to make a compromise cause I really cant afford 2.00+per foot or the 30.00+ per connector.

Have to agree, the LMR-400 or 9913 seem to fit the bill- acceptable loss, affordable, durable, inexpensive connectors, and readily available. Guess I need to focus on this type of coax.

BTW, has anyone used any Wireman type coaxes? It comes recommended by locals but need opinions from those with a broader knowledge base.

Thanks for all the suggestions. Keep them coming!
Dan

[linx]

I've done business with wireman and he seems to be full of knowledge, and is also quick on shipping. I'm assuming you're meaning the guy that calls himself wireman on the web.

He sells Times Microwave but also sells like 4 different types of generics. I'd just stay away from the generics. He does sell one that is a LMR-400 knock off made by Andrew's. I'm sure it's good.

[djrebel236]

I understand that LMR 400 is a quality coax and convenient as well. I only want to buy coax once so I thought Id ask if it will work with my set-up or do I need to upgrade.

Be aware that I have read Runaway's post but our parameters are quite a bit different.

Selection facts:

1. Run will be approx 150'
2. Power will consists of a 12 tube Elkin w/approx 1000 watts pep
3. May also be asked to work with a 2x4 worldwide volted to approx 1500-1700 watts pep

Any help is appreciated

Dan

it might work for ya, it might not, i had problems with the lmr400 junk, so i run the mini8x, if ya want a bigger coax, go with the rg213...Dj

[Doodad]

djrebel236

What kinds of problems did you have?? First Ive heard of and issues with the LMR-500.

Dan

[linx]

djrebel236

What kinds of problems did you have?? First Ive heard of and issues with the LMR-500.

Dan

I'm all ears too. I haven't heard of any problems with LMR-400.

There's really no comparison in line loss of LMR 400 to Mini-8. High quality vs sub par mass produced quality.

Please enlighten us DJ.

[djrebel236]

ok, i bought a 105 foot of it, took it home hooked it up the the swr's shot through the roof, so i took it back to the cb shop and had it shorted to about 96 feet, took that home and again swr way too high, so i disconnected it, put my old 20+ years old back on, the swrs dropped back down to normal(1.2 across the band)so than i went to another shop and got a line of 100 foot of the 8xmini and now it works great, low swrs and i can push power through it without any problems...Dj

[721HACKSAW]

Did you inspect the connectors for possible solder problems? You can have the highest quality coax, and a bad connector can cause severe problems. I work with all types of cables in my job every day, Times Microwave LMR-400 is the best type of coax I have ever used, it is much easier to work with as far as stripping and assembling connectors. I use the standard type for my fixed installations. (Imax ground plane) The flex type for rotation at the beam and all my jumpers are flex also. This coax has a 20 year life in sunlight applications. It may cost more but is well worth it in my opinion. Always use the best you can afford.

[Black Lightning]

ok, i bought a 105 foot of it, took it home hooked it up the the swr's shot through the roof, so i took it back to the cb shop and had it shorted to about 96 feet, took that home and again swr way too high, so i disconnected it, put my old 20+ years old back on, the swrs dropped back down to normal(1.2 across the band)so than i went to another shop and got a line of 100 foot of the 8xmini and now it works great, low swrs and i can push power through it without any problems...Dj

I have to echo what others were saying - you had something bad somewhere. Most likely a connector that wasn't properly installed. The LMR-400 is double shielded, with a braid and a foil wrap.

[Yaesu 101]

The only coax i will use is LMR-400. I have 3 runs to my shake. two runs are 200' each and one is 100' .All my jumpers are LMR-400F . I've had zero problems with it. Its good stuff IMO.

I would also like to add that IMO if your gonna replace the run to your antenna with LMR-400 be sure you get enough to make all your jumpers out of it as well or get some LMR-400F. This way all your coax has the same velocity factor. I'm not a fan of mix matching different brands/types of coax with different velocity factors even though I've seen many do it in the past.

[Magnetron]

Isn't LMR-400 overkill for a CB station at 27mhz? Can you really tell the difference on transmit or receive between a length of LMR-400 and an equal length of good quality RG-8 such as 9913 etc. ?

I can see using LMR-400 for vhf/uhf but I'm thinking that at 27mhz the issue becomes more one of vanity than actual performance.

But I certainly could also be completely, totally, and wholeheartedly wrong.

Peace.

- Darrell

[drdx]

I doubt between the 400 and 9913 you would, but on RG8 the quality varies so much you could see a difference. Brand is a huge factor and there is a wide variety of poor quality 400 out there to avoid. Most of the time on here you'll see 400 recommended due to power levels, and not just due to line loss, but the 9913 would handle the same power of lmr400 i would think. I think 9913 gets a little forgotten these days in favor of the times microwave brand name that did a better marketing job in the 90's and they are a little more popular brand in some crowds than the belden.

You do get significant line loss associated with long runs like that, and on top of that, if you only have to do it once you might as well do it right. Receive wise, other than the antenna and location, coax is a huge factor in determining receive quality, something harder to achieve than a big signal. He mentioned only having a certain amount of power and we all know that changes. It is not uncommon for bases to get into the multi-kw range, even for the non channel 6 guys, and quality cable is definitely essential then.

Welcome to the forum by the way, we're all casual there, and many of us here are hams as well.


-drdx

[998]

I know this is not good to say but man after finding the coax calculator I wish I would of saved a lil more money and used it buts that gives me another project to do but on that note it will get changed and i would like to thank LINX for bringing this coax to my attention :D

[linx]

No problem 998 Glad I can share the wealth bud.

Magnatron, the LMR may be a bit of overkill, yes. But here's my thinkin on the situation. I started my base running CB and started out with RG8X, then upgraded to RG-213 when running a little power. Upgraded my license to General back in February or so, and then bought a TS-2000 and upgraded once again to LMR400 for the low loss factor. I now have Heliax and LMR400 in my whole shack. If I would have just done it right the first time, I would have been done, and the LMR400 has a UV exposure life of 20 years. In the mobile I went from RG58, to RG8X, to LMR400, to RG213, to RG8X. So I've been all over the place in my truck, lol, but then again, I should have just did more research and stuck with 1 thing. The LMR is the only way I'll over go with my VHF/UHF mobiles, unless I just have to use something with high loss due to space restrictions.

[PONY EXPRESS]

That should work fine, but I'm sure someone will say LMR600 or something, but anything bigger will need different connectors and drive up the cost. I don't know what your antenna plans are, but if you are running a beam or something that requires more than one run, consider a remote coax switch like an ameritron or something so you only have to buy one run of the 150 ft. Make sure it is real Times cable and not some knock-off as I've heard that the off brand versions lack a little to be desired. I get mine locally at tx towers and it runs $1 a foot. -drdx

Heck I wouldn't run anything smaller than Andrews 7/8 hardline. We got to squeeze every watt to the antenna

[drdx]

Dang, 7/8, I'm underdressed. But, for that 1.2 stuff you play with, it ALL counts. -drdx

[MoJo]

I understand that LMR 400 is a quality coax and convenient as well. I only want to buy coax once so I thought Id ask if it will work with my set-up or do I need to upgrade.

Be aware that I have read Runaway's post but our parameters are quite a bit different.

Selection facts:

1. Run will be approx 150'
2. Power will consists of a 12 tube Elkin w/approx 1000 watts pep
3. May also be asked to work with a 2x4 worldwide volted to approx 1500-1700 watts pep

Any help is appreciated

Dan

Attenuation dB/100ft: .645
Attenuation db/100m: 2.115
total Attenuation (dB): .97
Average Power: 3.5KW
Efficiency: 80%

That was using times own calculator figured on channel 19 for a run of 150'