LMR Ultra Flex Coax

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436isthe1

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Hello I have a Uniden 436hp I use RG58 COAX at 50ft and a Hustler DCL-B base scanner antenna with earth ground. My reception is good but I have heard good reviews about LMR 400, but I need it to be flexible coax. would LMR 400 ultra flex work for me at a 50 ft run?
 

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mass-man

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if your scanning interests are in the 700/800mhz range, LMR400 of either variety would be a good idea. If you are a VHF kinda listener, even RG6 would be an improvement over your RG58.
The flexible part is very important when attaching the cable to your radio...you could always use the heavier stuff for 49.5ft and a short jumper to the radio. Looking at the Times Microwave LMR 400 info...
The regular LMR 400 has an attenuation of 3.9db per 100ft at 900 mhz
The flexible is 4.7db per 100ft at 900mhz
 
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436isthe1

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if your scanning interests are in the 700/800mhz range, LMR400 of either variety would be a good idea. If you are a VHF kinda listener, even RG6 would be an improvement over your RG58.
The flexible part is very important when attaching the cable to your radio...you could always use the heavier stuff for 49.5ft and a short jumper to the radio. Looking at the Times Microwave LMR 400 info...
The regular LMR 400 has an attenuation of 3.9db per 100ft at 900 mhz
The flexible is 4.7db per 100ft at 900mhz
I just need 50 feet, I listen to 700-900 mhz. would the lmr ultra flex work? Also is it true I need special connectors for lmr 400 ultra flex for 700-800 mhz?
 

mmckenna

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I just need 50 feet, I listen to 700-900 mhz. would the lmr ultra flex work? Also is it true I need special connectors for lmr 400 ultra flex for 700-800 mhz?

Yes, the Ultra Flex will work. You'll pay a bit more for the UF cable, and it'll have a bit more loss, but it's not going to be a big deal.

You don't need special connectors for those frequencies. It is true that some connectors are better than others for higher frequencies, but you should use what matches the connector on your antenna. Using adapters is not the preferred solution.

While LMR-400UF is a bit more flexible than standard LMR-400, it's still a heavy cable and no where near as flexible as the RG-58. Since the antenna connector on your scanner is a weak point, I would strongly recommend you use a short jumper to make the final connection to the radio. Order the 50 feet of LMR-400UF with a UHF male connector on the antenna end. On the radio end, order it with a Female Type N connector. Then order a short jumper of RG-58 (or LMR-100, etc) around 1-2 feet long with a Male N connector on one end, and an SMA male on the other end to connect to your scanner. This short length of flexible cable will take a lot of strain off the antenna jack.
 

436isthe1

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Yes, the Ultra Flex will work. You'll pay a bit more for the UF cable, and it'll have a bit more loss, but it's not going to be a big deal.

You don't need special connectors for those frequencies. It is true that some connectors are better than others for higher frequencies, but you should use what matches the connector on your antenna. Using adapters is not the preferred solution.

While LMR-400UF is a bit more flexible than standard LMR-400, it's still a heavy cable and no where near as flexible as the RG-58. Since the antenna connector on your scanner is a weak point, I would strongly recommend you use a short jumper to make the final connection to the radio. Order the 50 feet of LMR-400UF with a UHF male connector on the antenna end. On the radio end, order it with a Female Type N connector. Then order a short jumper of RG-58 (or LMR-100, etc) around 1-2 feet long with a Male N connector on one end, and an SMA male on the other end to connect to your scanner. This short length of flexible cable will take a lot of strain off the antenna jack.
Thank you sir.
 

rogress

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I concur with mmckenna.

I used LMR 400 (not ultraflex) from my antennas to my "radio room", then I used LMR 240 ultra flex jumpers to my receivers. By the way, in most cases, I used N Type connectors on my LMR400 cable - on the radio room side. Like mmckenna said, use the connector that matches your antenna on the antenna side of the LMR400. I also avoided adapters.

Then I ran that into a double female N barrel connector:

And finally a jumper LMR240 ultraflex with a N male on one end an BNC male on the other end. Sometimes my BNC male was a right angle BNC male.

They are expensive, but you can also go to usacoax.com and have custom cables made with just about any connector. For the LMR400 I bought the bulk cable, the connectors and crimpers and put the connectors on the LMR400 myself, but if I had it do all over again, I would just pay to get the 50ft LMR400 with desired connectors on it already. Good crimpers are expensive and if you don't use them much, it isn't worth it.

You can also get different patch cables to match your receiver, i.e. N type to SMA, N type to PL259, depending on the connector on your radio.
 
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W5lz

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Unless you have a very 'twisty' feed line run it would be over-kill. I doubt if it would be all that useful unless you do a lot of antenna moving.
 

mmckenna

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Thank you sir.

A few additional things...

If you want LMR-400, make sure you are getting Times-Microwave LMR-400. There's a number of vendors that sell "LMR-400 equivalent" cable. Sometimes that cable can be as good as the real stuff. Sometimes it's cheap Chinese cable that looks more or less something like LMR-400. Get the right stuff.

I agree that the LMR-400UF is a bit more flexible, but as others have pointed out, it's still going to be a pain to run. Get the straight LMR-400 if you can. I've run LMR-600 in my house, down a wall, etc. It takes a bit more effort, but it's not impossible. Using the short flexible jumper helps a lot.

Don't do any of this unless you plan on correctly waterproofing the outdoor connections. If you don't, water will get inside the connector and corrode out the copper.

No shame in ordering the cable with the connectors installed. As Rogress pointed out, the crimping tools are expensive, and unless you are going to be doing a lot of this, you'll save money by having someone else do the connector install. Some shops will even put heat shrink tubing on the connection. If this is offered, pay the extra few bucks for it. Good heat shrink tubing will have an adhesive inner lining that melts when heated. That'll act as a sealer (not to replace proper waterproofing) and as a strain relief. I do that on all the cables I make.
 

rogress

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Yea, mine setup was too complicated. I had 3 or 4 antennas in the attic and one outside up high. I ran LMR400 from each antenna to a patch panel like this: MFJ-4704, COAX PATCH PANEL, 4 POSITIONS, but put N type barrel connectors in the patch panel. Then the LMR240 ultraflex from the patch panel to the radios, with various plugs (BNC, N, SMA). Overkill, but fun to play with. Only makes sense if you have multiple antennas and multiple radios.
Unfortunately I've been in the process of dismantling because we are moving. Hopefully I'm not taking us down the wrong rabbit hole when this is supposed to be a simple question about ultraflex.
 

mmckenna

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I've used ultraflex and 'superflex' cables for jumpers. I've only used it as the primary feed cable on some small UHF repeaters where distance from the duplexer to the antenna was around 10 feet. Was just easier to use a 10 foot length of 1/4" Heliax superflex for the full run.
 
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