Hello all,
I am on a project to fit the Marklin 117993 retro-fittable Telex Couplers to some of my locos. I came across them online and bought a couple to try. The first locomotive I fitted them on was a 3681 BR220 diesel loco. which I had upgraded with an ESU Loksound V3-M4 decoder. This loco. had NEM standard coupler pockets so it was easy to swop out the standard close coupler & fit the 117993. As for wiring, I read about problems of over-cooking the 117993 actuation coils if they are connected direct to a function output from the decoder so after experimenting, I wired a resistor of 100 ohms in series between the function output and the 117993 and it works fine in that the 117993 does not get unduly hot when actuated. I should add here that its a good idea to use a 2 watt (or higher rated) resister as the resister does get quite hot when actuated.
After fitting, the coupler worked like a dream in that the coupling and de-coupling is really reliable, smooth and realistic. I then fitted another 117993 to my 37951 BR03 steam loco. and that worked great too. I should clarify that the 117993 does not work with the older Relex couplers (Relex couplers will couple but would let go when the train goes over are any unevenness in the tracks). But when pulling carriages fitted with Marklin close couplers, the 117993s works really well.
Encouraged by this success, I’ve bought more 117993s but with the new units I received and fitted to other locos., I have found that the 117993 have a tendency to occasionally let go (without being actuated) when pulling a number of heavier carriages, even those with close couplers. I think what is happening is that the close coupler hooking bar slowly rides up the 117993 hook with the pulling torque and movement until finally it gets near the top of the hook when it pops out & releases.
Has anyone tried this coupler and had similar problems? And if so, is there a solution? Any advise would be greatly appreciated.

Thank you Tom for letting me know that other users are reporting that V100 locomotives which uses these same 117993 Telex couplers are also letting go of towed carriages. Clearly, this shows the problem is more wide-spread that what I have experienced myself.

I have done more investigation and am beginning to have a better understanding of the problem. I have also been corresponding with Mr. Frank Mayer of Marklin Service to try to see what they can do to help. To save me re-typing the rather long explanation of the problem (in case anyone is interested), I have copied below my latest email to Mr. Mayer for your information.

While I appreciate that not all members are as keen as me on Telex couplers, I find this one of the most enjoyable aspect of Marklin trains. I bought my first Telex locomotive, a first generation digital 3665 BR260 diesel shunting loco. in the mid 80s and I loved it! So when I came across the 117993 with NEM fitting, I was very keen to fit these to the rest of my locos. And when they work, they works so well. The coupling and uncoupling is so smooth and realistic. Its just a pity that there seems to be a production fault in 117993s which in my case, show a very high failure rate. In addition to solving my problem, I also wanted to raise this issue with Marklin to try to see if they can fix this problem so that 117993 will work properly.

Anyway, I hope this information helps for anyone who is interested and I will keep you posted on my correspondence with Marklin.



Dear Mr. Mayer,

Thank you for your email.

I can send you the locomotive but I feel this is not necessary. The reason is that I have been doing a number of checks to try to understand the problem, as detailed below.

A bit of background information would help here. I initially purchased 3 units of 117993s. I installed the first 117993 in my 3681 BR220 diesel locomotive. It worked superbly well; the coupling and uncoupling was very smooth, and it was totally reliable when pulling carriages in that it never lets go - I have attached some photos of this installation - see files with names beginning 1 to 3.

I fitted the second 117993 in my 37951 BR03 steam locomotive and that worked perfectly too - see photos 4 to 6. Encouraged, I bought another 10 units of 117993, planning to fit them to all of my other NEM coupler pocket equipped locomotives.

The third locomotive I fitted a 117993 to was a 37768 BR216 diesel. The coupling & uncoupling worked fine except that the 117993 would sometimes let go of the carriages being towed without any un-coupling signal sent to the 117993. Since emailing you, I have tried the remaining stock of my 117993 couplers one by one on my 37768 BR216 and 3681 BR220 locomotives and have found that of the 11 I had left, 5 units of 117993 works perfectly - i.e. couples & un-couples perfectly, and never lets go of carriages being towed - I fitted one of these to my 37768 BR216 diesel - see photos 7 to 9.

The fact that the good 117993s work perfectly on either of these locomotives and the defective 117993 lets go of carriages when tested on either/both of these locomotives show that the problem is not due to the locomotive or the mounting; the fault is clearly in the 117993 couplers.

Of the remaining 6 units of 117993, I found that:-
a) One is faulty in that the uncoupling pin sticks in the up uncoupled position so that the 117993 does not couple even after the uncoupling signal is turned off. In fact, if I use a tooth-pick to push the pin down to the couple position, it takes quite a few prods to get it down after which it will couple with carriages. But once the uncoupling signal current is applied to it to uncouple, the uncoupling pin still stay up after the uncoupling signal current is turned off and it refuses to couple to carriages - in other words, the uncoupling pin sticks and does not move up and down freely;
b) 5 units of 117993 couples and uncouples fine but lets go of towed carriages.

As such, it is clear that the issue here is simply that the defective rate of 117993 is extremely high. In my case of having bought 13 units of 117993s, 6 units (46%) are faulty as listed above. Further more, the fact that good units of 117993 works perfectly on each of my locomotives while the defective ones lets go on all my locomotives show the problem is not due to the locomotive or its NEM mounting. Clearly, this means there is no need for me to send my locomotive together with faulty 117993 units to you.

I did some more investigation to understand how the faulty 117993 would let go of carriages. What I did was fit one of the defective 117993 onto a 37661 E52 locomotive. However, I did not wire the 117993 to the decoder - see photos 10 to 12 - you will see that the 117993's wires are not connected but is tied to the top of the locomotive. This means that while the 117993 will couple to carriages, there is no way to send current to the 117993 to uncouple it. What I found was that after coupling carriages to the 117993, the coupling is very secure; you can pull on the carriages repeatedly and the carriages will not let go, as how it should be. However, once the locomotive pulls the carriages for 1 or 2 circuits of my layout, the 117993 will let go of the towed carriages! After letting go, the 117993 looks normal in the coupled position; i.e., the uncoupling pin is in the lowered position. I initially thought that what is happening is that the carriages coupling bar is riding up & slipping over the top of the 117993's coupling hook. But an adjustment to raise the NEM mounting does not help, and the angle of the bar is identical to the other perfectly working 117993s on the other locomotives.

To investigate further, I applied a very small piece of double sided adhesive tape (sellotape that sticks on both sides) and stuck this onto the inside of the tow hook of the 117993. I then coupled on the carriages and sent the locomotive round the layout. What I found was that after 2 or 3 circuits, the 117993 uncoupling pin had worked its way to the up uncoupling position. I can see this as the double sided tape is preventing the carriages from being let go so easily. Of course, if the locomotive continues to go round the layout, eventually, the carriages will be released and the coupling pin will go back down into the coupling position.

Clearly, what is happening is that with these defective 117993 units, ongoing & varying towing torque being applied to its coupling hook while towing carriages round the layout will eventually cause the uncoupling pin to move up by itself thus uncoupling and letting go of the towed carriages. The fact that this happens even with the defective 117993s fitted but unwired (i.e. no uncoupling current can be applied to the 177993) means the fault has to be a mechanical issue inside the 117993.

Let me suggest this. I will send you all 6 of my defective 117993 units. When you receive them, please fit them onto a test locomotive and use it to pull carriages round a layout. You will find that of the 5 units that lets go, it will let go when it is not meant to. Note that you need to test it pulling carriages, not just by tugging on the carriages to see if it lets go. For some reason, it will only let go if the towing torque is fairly constant but varying. I have found that once the towing torque is eased, the uncoupling pin, having worked its way half way up, will fall back down once the towing torque is eased. So to test it properly, you must let the locomotive pull the carriages round a flat layout for a number of circuits.

As for the final defective 117993, you can see immediately that it is faulty in that the uncoupling pin sticks in the upper position.

I apologise for the length of this email but I wanted to make everything clear. Please let me know your views on my suggestion.

Thank you again for your help and look forward to hearing from you.

Thanks Glen for your post. Its good to know that my experience with 117993 problems is a lot more widespread as maybe this will motivate Marklin to address the issue. I just feel that its such a pity that such an enjoyable and flexible (easily retro-fittable to all digital locos. with NEM coupler pockets and an auxilliary function from its decoder) product is so badly affected by what seems to me is poor production quality to the extent that failure rates is around half. As I said, I will keep you posted on my correspondence with Marklin and hope that we can persuade them to do something about this.

Whilst writing, I should clarify that the 117993 only really works with close couplers. Relex couplers do couple but lets go as soon as the train goes over any uneven tracks or crossings; the Relex coupler bar is too high and is the wrong shape to securely couple to the 117993's hook. But with close couplers, and of course a perfect working 117993, it works brilliantly. I will see if I can post a video of this in due course.

I appreciate that some decoders can be set to limit the time the uncoupling signal is on to prevent heat damage to the 117993's delicate coils. But I find it just as easy to wire a 2 watt 90 ohm resister in series with the 117993. I did some experiments and found that the full output from a decoder would get the 117993 very hot after 10 seconds. But with a 90 ohm resister, it only get quite warm even after being on for 30 seconds. The fact that the 117993 coils can get so hot would indicate that the full output is excessive. I would guess that limiting the current with a resister would also reduce the strain on the decoder as well.

Anyway, will keep you posted on how I get on with Marklin.

Hello Pal,

Many thanks for letting me know of this posting on Stummis forum. No, I have not seen this. I regret I do not know German so cannot take advantage of Stummis. I did use Google Translate to work through this posting and it certainly is very useful information, thanks. I will certainly look into adjusting the setting and timing of the output to the 117993 later. But first I would like to focus my efforts to try to get Marklin to address what looks like a very serious quality problem in their production of the 117993 Telex coupler. As I have mentioned, I really enjoy Telex coupling and uncoupling. And I just feel its such a pity that a great product like the 117993 is spoilt by what looks like awful quality control in production. With my 117993 purchases, I have a 46% failure rate, and for Glen, its even worse.

I started collecting Marklin some 50 years ago when I was 9. And as we all know, the one thing we all appreciate Marklin for is quality. After all, my 3 oldest locomotives are a Marklin 3000 tank engine; a 3005 steam express and a Marklin 3031 with old style Telex. These were bought between 1962 and 65. I should clarify that I got them for many year's birthday and X'mas presents combined! And 50 odd years later, they are still running perfectly (post conversion to digital operation) on my layout. The 3031's old style Telex is still working perfectly to this day. So its such a pity that a Marklin Telex product of today can be so badly affected by such awful quality, especially when the product itself is so good when it works. So I am determined to try to see if I can persuade Marklin to do something about it.

Whilst writing, I have posted a couple of videos to show my 'good' 117993 couplers fitted and working so well. Hope you like them.

Bennett, All,
Friend Dennis the Train Dr tells me that the Msd outputs are not adjustable like the Loksound/lopi ESU ones are, however he tells me he has mastered the Marklin Decoder programmer, and looking thru the menus there are are lot of programmable features yet to be enabled by future updates, which should see the Mld/Msds equal or close to Lopi programablity with the special features Lopi/Loksnd decoders are famous for. I guess M has more software/firmware development to do, or are they waiting for the Cab Control feature as well for retrofitting ??
So at the moment only Lopi functions, can be turned down to save the couplers. I guess with factory M Loks using them this feature has been built in

Thanks Glen for the additional information courtesy of the Train Dr.

I have taken a few more videos to send to Marklin Service in an attempt to demonstrate to them that there is a problem with the production quality of 117993s. These are available for downloading on the following link in case anyone is interested.

http://we.tl/kK8ot0dhva

There are 3 videos, the first showing a bad 117993 fitted to my 37661 E52 elec. loco. which lets go of towed carriages after 45 seconds. The 2nd showing the same loco. fitted with a good 117993 which does not let go. Finally my 117993 fitted 3681 V200 loco. coupling and uncoupling and towing without problems.



Bennett.

Can a Telex coupler (E117993) be retrofitted to the rear of a BR 03.10 (03 1022) ex 29845 Starter set vintage 2000/01? I intend retrofitting a 60945 Decoder and replacing the existing coupler with the Telex if possible/practicable.

Also, why can't I locate information on this part on the Marklin website spare parts list? In fact, they don't appear to list any 'E' part numbers. Seems very odd to me.

Thanks,
Neil

Hi,

another option you have is using the Roco telex coupling, the main difference is from the type of coupling itself but the other main difference is when coupled it has 2 hooks to lock into which makes it a much more reliable coupling instead of sitting underneath the Märklin close coupling.
it would be preferable to use Roco coupling instead of a Roco Telex coupling with a Märklin close couplers, all depends how they line up.

Using an ESU lokprogrammer, there is a timer (as mentioned above) to control the duration of the telex coupler being active, 3 seconds is a bit to short for my likings but this a personal choice, I set mine on 5 - 7 seconds to make sure they'll uncouple, especially when you're loco doesn't start like a speeding bullet.
Also if there is pressure on the couplings it may be difficult for the telex (Roco) coupling to uncouple

John

Thanks Tom and John,

I've now determined that my BR 03.10 has a NEM coupler pocket so it will accept the E117993 Telex coupler. My other locos have this Marklin Telex coupler so I think I'll stick with the same type. Plus, to me, it looks more aesthetically pleasing that the Roco(?) shown in the video.
I note your comments re the timer function. I'll attempt to locate or set this on the CS2 once the Telex arrives and is installed. Wish me luck!

Markilin really needs to improve its customer service re the 'E' parts. After all, one can find good information (picture and description) on 'regular' parts such as 72021, 73406 etc. It doesn't make sense to me.

Cheers,
Neil