Need help with BNC to LMR-400 connector
- Thread starter Hawkeye59
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DPD1
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The distances are often a little different between brands, so it;s hard to say. If the brand is stamped on there, sometimes they'll have info on their site. But you're basically making two cuts... The outer jacket, then the center insulator down to the conductor... Since the braid is folded down, you probably don't have to cut that. You can figure out the jacket cut by using a probe to see how deep it is. Then obviously you can figure out the center insulation one by just looking at the pin. You've got the parts lined up in the right order, left to right. And the first ring has the part that makes contact with the gasket on the top. The the bottom of the gasket should have a slot that fits over that.
fineshot1
Member
That looks like the solder type. I would not even attempt to solder a conn on LMR400
due to the easily destroyed foam dialectric in this type of cable.
The one below is a crimp on and I believe requires a special strip & prep tool from
Times Microwave. You can actually prep without it but its a real PITA.
BNC Male Crimp Connectors - BNC male-Times LMR400
due to the easily destroyed foam dialectric in this type of cable.
The one below is a crimp on and I believe requires a special strip & prep tool from
Times Microwave. You can actually prep without it but its a real PITA.
BNC Male Crimp Connectors - BNC male-Times LMR400
I could not find an exact BNC connector install schematic but, I did find one for an N-type male. These connectors use the almost the same procedure for installation. Hope this file helps. You might have to strip the outer shield slightly more, check by trial and error, as you can re-use this type of connector.
K
kb0nly
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Ahh Phooey...
This comes up every time someone says the words solder and LMR400...
I have soldered connectors on LMR many times, no worries. Unless your going to use a 100w iron and be stupid about it you won't distort it any. You just need to heat it quick enough to solder on that center pin. If your really worried have a damp cloth nearby to quickly cool the center pin after soldering. Touch iron, heat, solder, cool... No problem..
If you had a crimper you probably would have bought a crimp on connector in the first place i'm guessing so why bother suggesting that now, use what you got. That guide posted by Luis is a good guide.. Basically for the center you just strip back enough that the center pin goes on and sits against the center dielectric, no extra length. Then remove enough outer jacket to clamp the braid into place.
I will say that i totally despise clamp on connectors, they never seem to make a good mechanical connection and always seem to feel a bit loose on the cable.
fineshot1
Member
Scott - you are experienced at it - the OP is not.
Crimping these types of connectors has been an industry standard for many years
now and works well if done correctly and lasts for many years - If you prefer soldering
and have the know how then have at it but the OP is not experienced enough to tackle
this and that's why I suggested the crimp style connector.
Howdy
Another point to be aware of is that some (not all) Crimper's designed for LMR may not make a solid connection, so check with the Times supplier to double check the Crimper & that the specific BNC you would use are fully compatible.
A few months ago a very well known company in the Dallas area made about 20 crimp-connectors & all had to be cut & thrown away as the tech used an 'old' crimper that was (he thought) still good for the LMR connectors, but apparently the supplier (in this case a 259 type) had slightly changed the design on the connectors just enough to hose things up....
Just an awareness point only, as I too have successfully used both crimped and the soldering methods...
At least with soldering you have a second and third opportunity...crimping is much closer to a 'one-shot' thing....you might consider asking a local Ham Radio Club (go visit a monthly meeting) and ask for help or a bit of hands-on....most Hams in local clubs are happy to assit...
Best of Luck.
Thx
Another point to be aware of is that some (not all) Crimper's designed for LMR may not make a solid connection, so check with the Times supplier to double check the Crimper & that the specific BNC you would use are fully compatible.
A few months ago a very well known company in the Dallas area made about 20 crimp-connectors & all had to be cut & thrown away as the tech used an 'old' crimper that was (he thought) still good for the LMR connectors, but apparently the supplier (in this case a 259 type) had slightly changed the design on the connectors just enough to hose things up....
Just an awareness point only, as I too have successfully used both crimped and the soldering methods...
At least with soldering you have a second and third opportunity...crimping is much closer to a 'one-shot' thing....you might consider asking a local Ham Radio Club (go visit a monthly meeting) and ask for help or a bit of hands-on....most Hams in local clubs are happy to assit...
Best of Luck.
Thx
BNCs for LMR-400
Even though I have soldered lots of connectors over the years, I bought these BNCs for LMR-400. I do have the correct crimping tools as well, it makes a big difference. I had no issues with these at all.
Even though I have soldered lots of connectors over the years, I bought these BNCs for LMR-400. I do have the correct crimping tools as well, it makes a big difference. I had no issues with these at all.
Well, at least you have the parts laid out in the correct order 
Look at this thread I made a long time ago, about half way down, it shows what to do.
Send me a PM if you want exact details, I've soldered over 200 LMR400 cables with all sorts of connectors so get in contact with me via PM's, and I can walk you through it with pictures. I wrote a small book for the guys at work on how to make ALL sorts of cable types and connector types.
http://forums.radioreference.com/an...35-homebrew-off-center-fed-dipole-pt-2-a.html
Look at this thread I made a long time ago, about half way down, it shows what to do.
Send me a PM if you want exact details, I've soldered over 200 LMR400 cables with all sorts of connectors so get in contact with me via PM's, and I can walk you through it with pictures. I wrote a small book for the guys at work on how to make ALL sorts of cable types and connector types.
http://forums.radioreference.com/an...35-homebrew-off-center-fed-dipole-pt-2-a.html
Hawkeye59
Member
Thanks for all the input gentlemen.. I went ahead and gave it a shot and had the following results.
With the LMR/BNC connector I managed to get it all together but noted the entire connector assembly will spin on the feedline once done. I suspect this is not normal.
With the plain LMR male connector I got it attached but never noted any lock into place as instructions said to expect from the pin. I crimped the sleeve with a crimper I ordered RFA-4005-20 CRIMP TOOL ONLY (W/O DIES), (HANDLES ONLY) - RF Industries - Icom, Laird, Pulse/Larsen, Polyphaser - Kollman Radio Electronics and die for LMR-400 RFA-4005-14 Die Set for LMR400/9913 - RF Industries - Icom, Laird, Pulse/Larsen, Polyphaser - Kollman Radio Electronics. Performed continuity check and it was good. Attached N connector to antenna through tube and when I went to tape feedine to pipe the feedline slipped out of the N connector.
SOOOO to prevent any further headaches I found some pre assembled Times Microwave LMR-400 on ebay.
Odd how after I made the URLs tiny at tinyurl and used that they show as they do in post
With the LMR/BNC connector I managed to get it all together but noted the entire connector assembly will spin on the feedline once done. I suspect this is not normal.
With the plain LMR male connector I got it attached but never noted any lock into place as instructions said to expect from the pin. I crimped the sleeve with a crimper I ordered RFA-4005-20 CRIMP TOOL ONLY (W/O DIES), (HANDLES ONLY) - RF Industries - Icom, Laird, Pulse/Larsen, Polyphaser - Kollman Radio Electronics and die for LMR-400 RFA-4005-14 Die Set for LMR400/9913 - RF Industries - Icom, Laird, Pulse/Larsen, Polyphaser - Kollman Radio Electronics. Performed continuity check and it was good. Attached N connector to antenna through tube and when I went to tape feedine to pipe the feedline slipped out of the N connector.
SOOOO to prevent any further headaches I found some pre assembled Times Microwave LMR-400 on ebay.
Odd how after I made the URLs tiny at tinyurl and used that they show as they do in post
DPD1
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If the braid was clamped down on properly, it should not spin in there. But the clamp style is indeed less physically strong than the crimped. I moved away from those (even though they are more weather resistant with the gasket) because people kept hanging the weight of the cable off them, and the clamp connectors are not meant for that. Actually, it's a bad idea to do that with any cable, but especially those. But if you're saying the crimp kind slipped out, I'm not sure what the deal is with that. It helps to crimp it down over part of the jacket. But no weight should be applied to those either. If the connectors were RFI, the tolerances should match the die well.
Use proper crimp on connectors with LMR-400
You do need to use the correct tools. Upon doing so, the connector will not spin. I've put on dozens of these, both N and BNC connectors, and had no problems.
When you get pre-made cables with connectors already on them it makes it tough (if even possible) to snake them through walls. Plus the cable ends up being too long and you coil it up, which is loss you don't need - the whole reason for going to the better coax in the first place.
I wouldn't. If you need an N connector, crimp on an N connector. If you need a BNC, crimp on a BNC.
You do need to use the correct tools. Upon doing so, the connector will not spin. I've put on dozens of these, both N and BNC connectors, and had no problems.
When you get pre-made cables with connectors already on them it makes it tough (if even possible) to snake them through walls. Plus the cable ends up being too long and you coil it up, which is loss you don't need - the whole reason for going to the better coax in the first place.
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