Times microwave LMR 400

zeppelin11

Member
Joined
Jun 15, 2012
Messages
70
Location
Marion County, FL
Hello, I'm looking for 15' of LMR 400 preferably by Times Microwave. However I don't have any of the equipment to crimp the connectors and I couldn't find already crimped connections of LMR 400 on the Times Microwave website. Unless I overlooked it? Does anyone know of a reputable website selling legit Times Microwave LMR 400 with the options of already crimped connections? I need a type N male on one end and SMA male on the other end. Much appreciate all feedback

-Bob
 

KevinC

Big Dog...celebrating 10 years of abuse!
Super Moderator
Joined
Jan 7, 2001
Messages
11,336
Location
Home
Hello, I'm looking for 15' of LMR 400 preferably by Times Microwave. However I don't have any of the equipment to crimp the connectors and I couldn't find already crimped connections of LMR 400 on the Times Microwave website. Unless I overlooked it? Does anyone know of a reputable website selling legit Times Microwave LMR 400 with the options of already crimped connections? I need a type N male on one end and SMA male on the other end. Much appreciate all feedback

-Bob
No help, but I would seriously reconsider a SMA on that coax. It’s going to put a lot of stress on whatever it’s attached to. At only 15’ you could get by with something a lot more flexible.
 

zeppelin11

Member
Joined
Jun 15, 2012
Messages
70
Location
Marion County, FL
No help, but I would seriously reconsider a SMA on that coax. It’s going to put a lot of stress on whatever it’s attached to. At only 15’ you could get by with something a lot more flexible.
The way I have the cable coming in is straight down to the antenna connection on the scanner and the scanner is stationary. I figured that would be the best way to not put strain on the scanners antenna connection but I could be wrong. I didn't want to have a run of quality cable going to rg 58 and degrade the signal since I'm having some spotty transmissions as it is. Or I could also go with flexible LMR 400. I'm open to all suggestions.
 

iMONITOR

Silent Key
Premium Subscriber
Joined
Sep 20, 2006
Messages
11,156
Location
S.E. Michigan

mmckenna

I ♥ Ø
Joined
Jul 27, 2005
Messages
23,615
Location
Hiding in a coffee shop.
The way I have the cable coming in is straight down to the antenna connection on the scanner and the scanner is stationary. I figured that would be the best way to not put strain on the scanners antenna connection but I could be wrong. I didn't want to have a run of quality cable going to rg 58 and degrade the signal since I'm having some spotty transmissions as it is. Or I could also go with flexible LMR 400. I'm open to all suggestions.

You've got some good reasoning there, but you're being a bit extreme.

At 850MHz, there's about 0.2dB of loss difference between 15 feet of LMR-400 and 15 feet of something much more flexible like LMR-240.
That tiny bit of difference isn't something your ears will hear. It does risk damage to your scanner, unless you secure everything so much that nothing can move, ever.

I wouldn't do that for that little bit of improvement.
 

W5ATX

Member
Premium Subscriber
Joined
Dec 19, 2002
Messages
214
DX engineering used to make custom coax connections, they sell whatever coax you want by the foot (in stock) and put whatever connectors on the end. it will be a little extra but...

I can say this, i've never seen an SMA on the end of any variant of .400 coax. If you're dead set on an LMR400 variant, i'd just order a 15 or 25' piece of chinese KMR400 from amazon with PL259's on each and and use an SO-239 to SMA pigtail on one end, and an N to UHF on the other.

And assuming you're using this for a scanner, i'd ditch the LMR400 altogether and go with some LMR240 instead. it's much more pliable than .400 and you're not going to notice any signal degradation. Even at 25' and the extra pigtail/adapters, If you were to measure it with a nano VNA you'll prob see <2dB insertion loss between LMR 400 and 240 at that length and frequency.

just my .04 cents (inflation) :)
 

ladn

Explorer of the Frequency Spectrum
Premium Subscriber
Joined
Oct 25, 2008
Messages
1,284
Location
Southern California and sometimes Owens Valley
Hello, I'm looking for 15' of LMR 400 preferably by Times Microwave. However I don't have any of the equipment to crimp the connectors and I couldn't find already crimped connections of LMR 400 on the Times Microwave website
The Antenna Farm is a trusted vendor here on RR. They make custom assemblies with Times LMR and other quality cables,

As others have said, LMR 400 is probably overkill and LMR 240 is a more reasonable choice as it is easier to work with , less expensive and won't put as much strain on your equipment's antenna connector.

If this is scanner use and not transmitting, quadshield RG6 might be a good alternative. Whatever loss due to mismatch will be negligible and it will be even easier to work with than LMR 240.
 

vagrant

ker-muhj-uhn
Premium Subscriber
Joined
Nov 19, 2005
Messages
3,149
Location
California
For those that read this thread do not know, there is LMR-240 which has a solid wire center and it is reasonably stiff, yet not as rigid as LMR-400. Then there is LMR-240UF. The UF stands for Ultra Flex and instead of a solid center wire, it uses a stranded wire center making it a fine solution when flexibility is needed. I am a fan of LMR-240UF for short runs/patch cables and vehicle use do to size and flexibility.

There is LMR-400UF as well, which is also a favorite of mine for portable use for longer runs/higher freqs.
 

Fixitt

Retired ASE CMAT L1 MRRT
Premium Subscriber
Joined
Dec 17, 2021
Messages
291
Location
Collinsville, Illinois
I bought several lengths of Times Microwave LMR400UF with N connectors from an eBay seller. They can do any length with most any connector.

Here is one :

 

G7RUX

Member
Joined
Jul 14, 2021
Messages
362
The way I have the cable coming in is straight down to the antenna connection on the scanner and the scanner is stationary. I figured that would be the best way to not put strain on the scanners antenna connection but I could be wrong. I didn't want to have a run of quality cable going to rg 58 and degrade the signal since I'm having some spotty transmissions as it is. Or I could also go with flexible LMR 400. I'm open to all suggestions.
LMR400 is good stuff but probably overkill for such a short run. That said, there’s no problem using it but I would strongly suggest usin N connectors on both ends and get a fly lead, perhaps LMR195, made up to jump from the LMR400 to the scanner. 400 is pretty stiff and you’ll almost certainly cause damage to the connector after a while.
 

zeppelin11

Member
Joined
Jun 15, 2012
Messages
70
Location
Marion County, FL
Much appreciate everyones input! I will certainly consider all advice. Ya'll are awesome for sharing your knowledge. I have another question if yall don't mind me asking that has me dumb founded. When it rains and it doesn't even have to be much rain maybe 5 minutes of very light rain. I won't pick up the system I'm monitoring. I'm getting signal bars on the scanner but no transmissions are coming through. and where it says "data" at the bottom right of the screen stops showing up. However the word "data" will also disappear and the transmissions stops randomly throughout the day/night. I do have the cable to antenna connection waterproofed but even if I didn't I doubt that would completely stop transmissions. I was able to raise the antenna another 6' putting the total height of the antenna to about 20' in the air. And I did see an improvement with picking up transmissions as well as coming in clearer but then out of nowhere I'll lose the data and no transmissions. My scanner is a Uniden BCD436HP. My antenna is a PCTEL 806-866 MHz 6dB 3 Element Yagi Antenna. Coax is RG8X 50 Ohm by Mookeerf at a 25' run. I'm monitoring a 850mhz simulcast system. I'm only 15 miles away (line of sight) from the tower I'm pointed at. I've Also tried moving the antenna around with little improvement. By what you all say and others as well I should be having no problems picking up this system with the equipment I have and being just 15 miles from the tower which makes me start to wonder if it's the scanner itself that's the problem and maybe needs to be sent in to Uniden to be checked out. I've had this scanner just shy of 3 years. Again, all opinions are welcomed and appreciated.
 

iMONITOR

Silent Key
Premium Subscriber
Joined
Sep 20, 2006
Messages
11,156
Location
S.E. Michigan
When you raised your antenna another 6' did you ad a coax jumper with more connectors? Are these factory manufactured cables & connectors or did you do them yourself? It's possible rain/moisture is getting into the connectors that by now might have corroded them Did you weather proof all the connectors originally? RG8X has a high loss at 700-800MHz.

At 15 Miles line of sight you should be able to monitor the signal with the stock back-of-set antenna. Have you tried that?
 
Last edited:

zeppelin11

Member
Joined
Jun 15, 2012
Messages
70
Location
Marion County, FL
No coax jumpers, no added connectors. A straight run with only the connections at each end of the cable. Connectors came crimped and waterproofed from the manufacturer. I also waterproofed the coax connection to the antenna. I have only had this antenna and coax for 2 months. I got the antenna from the antenna farm and this coax from Amazon. What is back-of-set antenna? I haven't heard that before.

MOOKEERF N Male to SMA Male Cable RG8x Coaxial Cable 25FT Low-Loss 50 Ohm Coax Cable Type N to SMA Extension Cable Jumper Cable for Antenna/Surge Arrester/Routers/Ham Radio/WiFi Signal Booster https://a.co/d/99EirAI


 

ArloG

Member
Joined
Feb 14, 2020
Messages
297
Yaaa. I purchased 200' of LMR 400 from HRO a few years ago for $0.99/ft.
And I still have a hundred feet or so of 9913 on a spool.
The only N Type connectors I have ever used are high quality Amphenol and other brand from my once local electronics surplus supply.
They're all compression fittings. And they work fantastic. For a fraction of what they cost retail.
Out of the blue I cut a few inches of coax from the antenna side and resoldered the center pin on and reused the connector.
No difference in signal which was awesome anyway. That compression connector was out in the weather for 6 years prior.
For weather protection I use clear Flex Seal spray. Leave the connector a turn or so loose.
Spray it all good all around. Then tighten it all up. Wait a few minutes and spray it again.
Suggestion. If you use slick outer jacket LMR 400. And compression connectors. Lightly sand an inch or so of the outer jacket after the compression sleeve, washer and rubber seal is on the jacket. To reduce strain on the connector perhaps make a large radius drip loop.
 

zeppelin11

Member
Joined
Jun 15, 2012
Messages
70
Location
Marion County, FL
I'm assuming the yagi antenna is aimed in the proper direction?
That is correct. I found the locations of all the towers for this system. I attached a picture. The line going from heart to heart is my location to the nearest tower. The X on the map are the other towers. I've had it aimed directly at the tower as well as a little off to the right in case I was picking up one of the other towers. I found the longitude and latitude of the tower and used a compass with degrees to get the antenna pointed at the correct tower. I also used a short jumper from the scanner to the antenna and adjusted the antenna until receiving the best signal. So after getting and doing all I've stated above the only thing I can think of is I need a better low loss cable run or there's a malfunction with the scanner itself. Screenshot_20230329_152844_Maps.jpg
 

zeppelin11

Member
Joined
Jun 15, 2012
Messages
70
Location
Marion County, FL
Yaaa. I purchased 200' of LMR 400 from HRO a few years ago for $0.99/ft.
And I still have a hundred feet or so of 9913 on a spool.
The only N Type connectors I have ever used are high quality Amphenol and other brand from my once local electronics surplus supply.
They're all compression fittings. And they work fantastic. For a fraction of what they cost retail.
Out of the blue I cut a few inches of coax from the antenna side and resoldered the center pin on and reused the connector.
No difference in signal which was awesome anyway. That compression connector was out in the weather for 6 years prior.
For weather protection I use clear Flex Seal spray. Leave the connector a turn or so loose.
Spray it all good all around. Then tighten it all up. Wait a few minutes and spray it again.
Suggestion. If you use slick outer jacket LMR 400. And compression connectors. Lightly sand an inch or so of the outer jacket after the compression sleeve, washer and rubber seal is on the jacket. To reduce strain on the connector perhaps make a large radius drip loop.
Much appreciate the feedback!
 

a417

U+0000
Joined
Mar 14, 2004
Messages
4,650
I'm not buying , nor do i ever suggest anything from amazon/ebay that has a seemingly random collection of 8 to 9 all caps letters leading the listing (MOOKEERF, SUPERBAT) . That stuff is knockoff-central.

Buy a reputable name from a reputable vendor.
 

zeppelin11

Member
Joined
Jun 15, 2012
Messages
70
Location
Marion County, FL
I'm not buying , nor do i ever suggest anything from amazon/ebay that has a seemingly random collection of 8 to 9 all caps letters leading the listing (MOOKEERF, SUPERBAT) . That stuff is knockoff-central.

Buy a reputable name from a reputable vendor.
I agree 100% I myself was skeptical with this cable from the beginning. the only reason I went with this is it had the end connections and length I was looking for. That is also why I created this post looking for a reputable website that offers LMR 400 by Times Microwave or similar quality with the connections and length that I'm looking for.
 

mmckenna

I ♥ Ø
Joined
Jul 27, 2005
Messages
23,615
Location
Hiding in a coffee shop.
Before you replace anything...
Take your scanner back up on the roof and connect directly to the antenna. See if it will successfully decode traffic.
If it does, I'd take a closer look at all your connections. Disassemble all of them and look for water intrusion, corrosion, damage, etc.
If it doesn't, I'd take a closer look at your programming.

I agree that cheap coax is a gamble, but I'd not be too quick to rule it out as the cause. On a run that short, even really cheap coax should get something into the radio. A 3 element Yagi pointed directly at the site should result in a pretty strong signal and would overcome a lot of coax loss.
 
Top