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Microdot to Lectro TA5 failure


BrianBinning

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Recently on set one of my lavs stopped working and I traced it to the Microdot to Lectro connector (part# is DAD3056). I'm not sure what happened exactly but the threads were pulled right off of the connector. The threads remained inside the Microdot connection but I was able to pull them out with needle nose pliers. You can see in the photo that the tip of the connector on the left is smooth where the threads came off and the intact connector on the right is still threaded. I'm curious if this has happened to anyone else. These babies are $100 bucks a piece so it's a bit of a loss but a necessary item.

 

I noticed there is a knockoff of these adapters made by YPA. Anyone tried one of these?

 

IMG_5109.jpg

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I 've worked with the YPAs when the old original DPA adaptors were still delivering very hot in gain on the Lectros. DPA changed their configuration some years ago, since then their adapters work smoothly.

YPA has the right config, but the threading on the microdot side of my adapters was poorly made and with actors movements they easily lost connection. Maybe this has been fixed in the meantime, but when the new DPA 3056 came out I switched back to the originals and have not have any failure since then.

 

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Agreed on the hardwired TA5F if you don't need microdot compatibility elsewhere.  We had several 4060's where the microdot end of the cable failed and I repaired them by wiring direct to TA5F.

 

Interestingly, the DAD6012 adapters we used to use were sold specifically for use with the (now ancient) M185 VHF transmitter.  Those (and more recent ones like the DAD6021) connect the shell to pin 1, which on the VHF transmitters shorts out the VHF antenna.  Rewiring direct allows one to change this if desired - although while we still use our VHF transmitters on occasion I highly doubt even we would use a 4060 with them any more.

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On ‎7‎/‎23‎/‎2018 at 10:39 AM, Dalton Patterson said:

I have heard that every time you connect and disconnect a micro dot connector you are loosing contact. The more you plug and unplug, the quicker your contacts wear out. In addition to the microdot assembly being somewhat fragile. 

 

They look cool. 

Hm. Never heard that.

 

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  • 2 weeks later...
On 7/26/2018 at 10:49 PM, RadoStefanov said:

Never heard that.

Me neither, at the time I heard it. I was skeptical but retained the information. Here is some info I managed to find that explains what I was referring to as "Insertion Loss". I am not 100% this is talking about the same thing. I am referring to the loss of plating on the contact of the physical pin itself decreasing over time and therefore decreasing your RF passing through the SMA connection. I think the accurate description would be copper losses. 

 

-----------------------------------

What is Insertion Loss and how is it specified?

Dec 23, 2014 
 

Insertion Loss, expressed in dB is defined as 10*log (Po/Pi) where Po= Power Out and Pi=Power In. There are 3 main causes of Insertion Loss: Reflected losses, Dielectric losses and Copper losses. Reflected losses are those losses caused by the VSWR of the connector. Dielectric losses are those losses caused by the power dissipated in the dielectric materials (Teflon, rexolite, delrin, etc.). Copper losses are those losses caused by the power dissipated due to the conducting surfaces of the connector. It is a function of the material and plating used.

In general, the insertion loss of a connector is on the order of a few hundredths to a few tenths of a dB. As with VSWR, it can be specified as a “flat line limit” or as a function of frequency. A BNC connector is specified at .2 dB maximum when tested at 3 Ghz. For the SMA, the requirement is .06*SQRRT Frequency in GHz when tested at 6 Ghz. For example, at 4 Ghz, the requirement would be .06*2 or .12 dB max. Although the connectors are specified to operate over a wide frequency range, they are only specified for testing at particular frequency because the test procedure required to obtain accurate measurements of such small losses is a very precise, and time consuming process.

Amphenol RF Link

-----------------------------------

 

For anybody curious, this all started on my end because I used to take my antennas on and off in my wireless case until somebody told me that was a bad idea because you loose .00001db of RF each time. I replied, ohh. ok. Unsure as to the validity of the statement. However after further research. I tend to follow that way of thinking and now keep my antenna's and SMA connectors connected unless necessary to disconnect. 

 

I hope this helps. 

 

Stay cool in that Vegas heat @RadoStefanov!!!

 

Best, 

 

Dalton

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Dalton and Rado,

Increased losses from connecting and disconnecting RF connectors is pretty much a myth. I would get a very tiny magic marker and mark a tiny line on the side of the SMA or BNC connector. After I counted 10,000 lines, I would put on a brand new connector.

Best Regards,

Larry Fisher

 

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IMG_2625.jpg

 

Pick N' Pluck for the win!

 

In conclusion, for all intents  and purposes I will keep the connectors connected. Thank you both for your responses. 

 

15 hours ago, LarryF said:

pretty much a myth

I am unclear. Does the loss exist? However it that the loss is not practical loss ( i.e to be able to be shown on test equipment)? 

 

15 hours ago, LarryF said:

mark a tiny line on the side of the SMA or BNC connector

Are you suggesting I make a new mark every time I connect/disconnect the connector? That will add significant time to my workload over a long period of time keeping track of that process. In addition to physically taking on and off the connectors, I would also have to mark them with a line. I have heard of this process to keep track of the number of uses on components, but feel an alternative approach could be successful ( i.e. keep the antenna's connected at all times). 

 

15 hours ago, LarryF said:

After I counted 10,000 lines

I better have a house and be retired. Haha. 

 

I get the Idea, I am not going to worry about this issue any longer. 

 

I appreciate your time guys!@

 

 

D

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  • 3 years later...

Hey friends, revisiting this thread as I have had issues with DPA's 3056 Microdot to TA5f connectors recently.

I purchased a batch of new 6060 lavs (yay) and thought I'd try to save a few bucks by using Deity microdot-TA5f adapters.. no such luck, they were noisy as hell. 10dB of noise, at least.

So I returned them, and grabbed a couple more DPA 3056 to make things right. Think again! turns out one of them didn't appear to pass signal normally, only when I tapped on the 6060 really hard, a burst of what I'd call "Lectro RF chamber" type noise was produced, so, nothing near usable. I went to my local Trew Audio Toronto shop to try another one, it wouldn't pass any signal unless I pulled the connector over at an angle.... that intermittent signal sounded 'full range', at least. These were all tested with brand new 6060's, so I think it's safe to rule out the microphones, and I rotated these through different Lectro transmitters to be sure I was narrowing this down to the adapter. All Tx + Rx + pre-amp gain stages were matched appropriately.

I understand the physical threading problem stated above, but anyone else had any signal issues like these with the DPA 3056 adapters??

Helpful to know they are warrantied for 2 years.

Attached is a video and recording illustrating the issue. 

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  • 2 years later...

I use my DPA 4060s with many different devices so I have kept them terminated as microdot but I have had to get the microdot ends on the mics rewired several times due metal/solder fatigue caused by people screwing the microdot end instead of holding it still and turning only the adapter to screw it on.

 

I have had 2 of DPA's microdot 56 Ta5f adapters fail and they are unrepairable.  Wiggling them in a lectrosonics transmitter causes break up, glitch/spalt sounds and audio drop out.  I tried electrical cleaner but this didn't help.  Making the same movements whilst in the transmitter with other adapters caused no problems so clearly they are broken somewhere inside.

 

Pity they aren't unscrewable to access and repair inside.

 

When recently purchasing a Tentacle Track E I was pleasantly surprised to be offered a Tentacle microdot to screwable mini jack adapter at a fraction of the price of a DPA one!  So far so good....

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12 minutes ago, RadoStefanov said:

100% DPA microdot user.

Never a single issue. IMHO they are indestructible. DOnt know about knock offs

 

Just to confirm the DPA 56 Ta5f microdot adapters I bought and used were all made by DPA and bought through a national distributor for DPA.  The 2 microdot adapters that failed were DPA made.  

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1 minute ago, DeafDave said:

Just to confirm the DPA 56 Ta5f microdot adapters I bought and used were all made by DPA and bought through a national distributor for DPA.  The 2 microdot adapters that failed were DPA made.  

To be honest I have 5 of those and used them twice. TA5 is the weak link not the Microdot. Mine are all Lemo3 to microdot.

 

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On 11/21/2023 at 6:15 PM, DeafDave said:

Pity they aren't unscrewable to access and repair inside.

 

The ones I have actually can unscrew.  They have threads between the two sections of metal, which had a sealant/adhesive on them so they are quire stiff.  If I remember I had to put one end into a vise and twist the other with pliers.  I probably used a buffer of some sort of softer material to prevent/reduce scratches.

 

The inside portion of the microdot connector was a sort of pin socket into which one of the component leads fit.  This allowed the two pieces of shell to twist when threading.  I suppose this is where a failure of these adapters is most likely.

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Would you have any photos you could share of the parts unscrewed and whats inside please Matthew?

 

Were you able to repair them without further problems?

 

What brand are yours?  DPA?  Deity?  other Chinese knockoff?  and would you have a link for where to purchase please?

 

I can see where the join is on my DPA ones, they are €105 to buy new from DPA so I might try opening them with 2 pliers before I throw mine out!

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