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Anyone tried SSM/ZMTs Lemo 3 pin soldering??

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I am trying to solder LEMO 3pin connector for SSM transmitter soon. But I figured the pins inside LEMO are so tiny and the bigger problem is Cos11d's wire itself is so fragile and thin specially white wire.

I searched here and there...but not easy answers for me. Anybody can give some tips??

Pre-soldered Lavs are kind expensive.

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Others with more skill than myself might have better info. If you are careful and have the right tools it can be done successfully. I have done quite a few and done repairs as well when they get yanked. The right connectors for starters are essential. Genuine lemos all the way. Avoid the cheap knockoffs or pay the price of finding out they dont actually connect. Push-pull or threaded are a matter of personal preference. Good solder iron w swappable tips to get the fine point. good solder of the smaller diameter and a ring light magnifier on an articulating arm is helpful. And last but not least some patience! Its fun to say you did it. But now i pay the higher price for the usual suspects to do it for reliability sake. When they do it on the frequent they to a better job than i can these days

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Tip 1: put a card between the pins so you don't accidentally solder them together.

 

Tip 2: Pay someone else to do it and avoid the frustration. This what I now do. It costs me to much in whiskey to calm the nerves afterwards.

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In addition to the good advice above:

Good wire preparation is key.  Solder once and quickly using a fine tipped iron after tinning the leads and contacts

I like to snip off pin 2 since it's not needed on a lav.

Clamp both the pins and the wire in place, don't try to hand hold.

 

 

Edited by Wandering Ear
Corrected pin number

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Man this is already killer advice i wish i had bumbling through the learning curve. That card trick will come in handy. Ive snipped pins on ta5f's but never occured to me on these. Just for fun start with building alexa mini audio input lemos that way these 3 pin lemos will be cake

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32 minutes ago, Derek H said:

Crucial to have the correct sized crimp die. 

Another good point there are 2 popular styles of strain relieve crimp and the little "fingers". The fingers seem to lock good on sankens but not so much on dpa and b6's. If you heatshrink to build up the cable just slips thru unless you glue the shrink good to the cable. Someone please correct me if i am wrong but i believe the crimps are on push pull connectors and fingers on the screw on's?

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What you call the "fingers" are really a split collet that close down over the outer jacket as you tighten the back barrel nut. I avoid the compression crimp style as once the collar is compressed there's no going back to do any repairs. The tough part of soldering an older COS-11 is that the 3 wires have developed a mind of their own and refuse to stay still when you have to resolder them. Here's trick I use, once the wires are connected to the pins and you're sure there are no shorts, etc cover the exposed connections with clear nail polish. That will insulate all the connections from shorting out when you put the two half round clamps around the pin block. One more tip, there is a raised key way above pin 1 (ground) get a Sharpie and mark it black, that makes it easier to see it and line up the cut out opening in one of the half round clamps. OTOH life would be a lot simpler and less expensive if all TX units used a TA5 connector.

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I had the wiring down without too much trouble but failed when it came to not having the right crimp die. It’s really frustrating when you get the soldering part done nicely and then chew up the job with too big or small of a crimp. I couldn’t tell you what the right size is but I’d recommend asking someone who makes a lot of them like a service tech at Sennheiser or Gotham maybe. Lemo is completely unhelpful as their manual only recommends using their own brand crimper and die which costs like $700. 

 

Knowing that now I’d probably recommend going with the screw-down collet version which also would allow a little more variance in cable diameter. It’s too bad they’re a good bit taller than the crimp version. I was always worried it would get torqued. 

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9 hours ago, Wandering Ear said:

I like to snip off pin 3 since it's not needed on a lav.

 

I don't know about SSM or ZMT but Sennheiser and also Wisycom has the bias voltage and audio input on pin 3. Snip off pin 2 instead.

 

Voice Technologies uses a screw type Lemo connector without the crimp part which is much more easy to assemble. I don't know if it's an original Lemo or some kind of knockoff.

Ambient has them in stock.

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Which pin is which depends on which side of the connector you're looking at, plug side or solder side. From the solder side I use this

 

                                         *  ground

 

                   * NC                                                 * positive/audio

 

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On 3/22/2019 at 7:25 AM, astro said:

 

I don't know about SSM or ZMT but Sennheiser and also Wisycom has the bias voltage and audio input on pin 3. Snip off pin 2 instead.

 

Voice Technologies uses a screw type Lemo connector without the crimp part which is much more easy to assemble. I don't know if it's an original Lemo or some kind of knockoff.

Ambient has them in stock.

You are right, I had remembered the pin numbering wrong.  It's pin 2 that is unused.

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3 hours ago, Wandering Ear said:

You are right, I had remembered the pin numbering wrong.  It's pin 2 that is unused.

That will give you more room but if you ever want to use that expensive Lemo with a COS-11, Lectro's wiring calls for a pin 2 connection for lowest distortion, i.e., the best COS-11 wiring uses all three pins. The simple explanation is that the COS-11 was designed as a three wire lavaliere. If you aren't going to use Lectros or COS-11's ,then happily whack away.

Best Regards,

Larry Fisher 

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On 3/22/2019 at 9:38 AM, Nate C said:

Tip 1: put a card between the pins so you don't accidentally solder them together.

 

I use a 'wedge' of Kapton tape... Highly heat resistant. 

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9 hours ago, LarryF said:

That will give you more room but if you ever want to use that expensive Lemo with a COS-11, Lectro's wiring calls for a pin 2 connection for lowest distortion, i.e., the best COS-11 wiring uses all three pins. The simple explanation is that the COS-11 was designed as a three wire lavaliere. If you aren't going to use Lectros or COS-11's ,then happily whack away.

Best Regards,

Larry Fisher 

Thanks Larry.  So far all the lectro lav wiring I have done is TA5 so I hadn't looked into the ssm wiring.  All the lemo's I do are for Zaxcom, and Zaxcom uses pin 2 for the 2nd channel (stereo) input.  I will keep this in mind.

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All this info has been discussed in multiple threads on JW. FYI you can get by with a  .10 crimp on the 00 lemo.

 

If you undertake this endeavor be prepared to invest many hours and possibly trashing a pin assembly or two.

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On 3/28/2019 at 3:06 PM, martijn76 said:

I used the ODU model on cos11, made it work on the first try, only because got some great tips on howto from the fine people here. Thanks so

much.

 

 

If the ODU model the one with the pressure chuck strain relief?

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very doable i did the 5 pin Lemo audio cable for the RED with shrink tubes and the same tip i used for XLrs  hihi

trick for me when soldering these tiny pins was do proper strip work tinning and in the case of the 5 pin nicely thin out those wires. since most cables just wont fit without fucking it up. 

unlike every normal soldering job i pre tinned my solder iron instead of feeding it while soldering, if you do feed tin ,chances of bleeding the solder to the pin next to it is rather high. using decent amounts of flux (non corrosive, like flux for PCB like 186) helps allot to, since the tin will flow better without using more of it and potential screw it up. this flux can be removed but even when left on it wont screw up the contacts or the wires.

lastly have desolder wig at hand. you can save a screwed up Lemo with a blob of flux and a solder wig to get rid of all the solder and start from scratch.

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Ah, nice thread.  I have been soldering Lemos since Aaton /Nagra IVS/HHB PortaDat days, successfully I might add.  But there are some great tips here that I have never tried that just make so much sense.  Yer never too old to learn I say.

 

Thanks all.

 

D.

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