Digital Power Track R8206

[MaartinL6]

This piece is actually marked as R8206 on the bottom -  it came in the digital Mixed Goods set (R1075) along with digital Select controller.   I have been advised that the analogue version has orange buttons (as mine in pic) but the digital has black buttons?  Does anyone know if this is correct?  Note that I bought the set at least 8 /9 years ago in the UK but I am only just setting it up for the first time (long story - live in NZ now).  I ask because one of the locos doesn't work at all (the other one does though and can be assigned an ID via the Select etc) but I can't see that Hornby would provide the wrong power track (it is also pictured on the Mixed Goods set box with the orange buttons).../media/tinymce_upload/3bb35e6ad9c36a4d7412060d1d4f5ab0.jpg

[Chrissaf]

...but I can't see that Hornby would provide the wrong power track...

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Wrong assumption......they certainly did.....well at least the Chinese factory did....read on.

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Yes that power track in your photo is an analogue DC R8206 power track. It is a known fact that the Chinese factory included in some Digital sets (particularly the early ones, like yours) the R8206 in error. The Digital power track is the R8241 with black buttons. However, given your current NZ location you don't need to try and source a R8241, the R8206 can be easily converted to being digitally friendly.

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The cover between the rails can be lifted to reveal a suppression capacitor. Snip out the capacitor and replace the cover.....voila you now have a digital power track....see image below, which also shows the conversion of the Analogue R602 DC clip to a R8242 DCC clip:

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/media/tinymce_upload/fba8d3c18e31ec77db3bd38d29af91cc.jpg

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The DCC track voltage is a Bi-polar square wave. It can be considered as a form of AC. The suppression capacitor passes AC, thus it acts as a shunt across the track to your DCC signal. It also distorts the waveform shape. The Select controller is particularly prone to the adverse affect that the capacitor has.

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Congratulations on actually knowing that there is a difference between the 'tan' and 'black' buttons. Many posts on here relating to digital control issues are subsequently proven to be down to the wrong power connector being used. But it takes several posts of dialogue to tease out the information about what type of power connector the 'poster' is using. Also, many issues are proven to be as a result of using the R8201 on a DCC controlled layout.....see paragraph below. As you now might guess, this issue comes up so often that we now have a prepared image (above) to post regarding the mod.

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Just for completeness of information, just in case it becomes relevant. The track power clips used with the R8201 Link Wires also contain the suppression capacitor in both clips. Despite what one might read in product description blurb, the R8201 is not DCC friendly and was always meant to be used just on DC Analogue layouts. Hornby's R8232 DCC point clips perform the function of the R8201. If anyone really feels that they need to use a R8201 on a DCC layout, the capacitor removal modification must be performed on them too.

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TIP: I write long posts. If you intend to write a reply, it would be appreciated if you didn't use the 'White Arrow in Blue Box' button. This is not a 'Reply to this post button. It is best to write any reply you want to make in the 'Reply Text Box' at the very bottom of the page and click the Green 'Reply' button.

 

Particularly as my reply includes an image. If you use the blue button, any reply you write, may be held back for image approval. Even though it is already a previously published image.

[ellocoloco]

I've read countless post regarding the R8206 and the capacitor and ignored them completely................

 

I have been using the track from a Thomas starter set I bought of my son (who still shows no interest) as a test track connected to a Multimaus and one of my locos - a decent Roco effort running a Lenz Gold - would often stop and refuse to do anything for a while..............all others seemed fine

 

A few months ago I had a real Doh! moment and popped out the capacitor realising I was making the same mistake as countless others............

 

The difference in performance is outstanding.

[MaartinL6]

[snip]

 

Hi Chrissaf - great response and info thanks.  Wierdly, when I removed the cover of the R8206 (as above) there is no capacitor...!  Very strange as I have never used this set until recently.  Assume this mean it will be OK for DCC use?  Cheers Martin

[Chrissaf]

Martin,

Notice the [snip] in your reply above. This means that you did use the 'Blue Button' even though I advised against it and your reply was held back for image approval by admin. The [snip] shows that the forum administrator has snipped [removed] all the unnecessary re-quote of my post, prior to releasing your reply for publication. If you had just scrolled down and used the bottom reply text box as I advised, then your reply would have been published instantly. Please please please try and avoid using the 'Blue' button. The forum threads read more efficiently when it isn't used.

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Yes, if there is no capacitor present, then your set must have been in a batch, where the Chinese factory started performing the DCC mod at the factory prior to including the correct black button R8241 power tracks in the sets. As long as the capacitor is not present, then it is DCC friendly. But do check ALL power clips if you have more than just one single track connector. The R8201 for example (if you use one).

[Sultan]

Based on the above should we also remove the small round orange  capcitors wired across the motors in locomotives?

[96RAF]

Based on the above should we also remove the small round orange  capcitors wired across the motors in locomotives?

These capacitors only see PWM DC not the DCC signal so they can be left in place but removing them is acceptable as suppression is present in the decoder.

Rob

[Fishmanoz]

Adding to Rob‘s answer - the capacitors in power tracks and clips go directly across the DCC track signal and are cumulative in effect when there is more than one.

 

Then capacitors are open circuit to DC and have lower and lower impedance as frequency (and capacitance) increases.  So they tend to first distort then short out the DCC signal to the point where they affect operation.

 

The suppression capacitors on motors are across the decoder motor output, not the track.  They operate individually on the motor outputs and not cumulative like the power track/clip capacitors. Also, their capacitance value is low enough that their effect on the motor output is minimal so usually don’t cause performance issues. But they are certainly not needed and do not improve performance. Better to remove them to be sure.

[GWR LNER fan 4472]

Hello,

 

I read this topic a while back and have only now got round to sniping out the capacitors on my layout. I have 4 power tracks on my layout (using Select and Walkabout) - three R8206 (tan coloured buttons) and one R8241 (green buttons). When I went to snip out the capacitors, one of the R8206s didn't have one in (as with MaartinL6 above). The one had a yellow capacitor and the other blue. The R8241 was a recent purchase (last year), but the R8206s I got in the Mallard analogue set 2013 one came in the DCC Pullman set with Clan Line around 2007 and I'm not sure about the other, bought seperately I think.

 

Anyway, our trains often take a bit of nudging to get going and often stop in the middle of the track. I thought this was just a part of model railways. The track is regularly cleaned with the Hornby track rubber and no dirt is on the rails, so I know that's not the problem, so after reading this, I thought it might be because of the extra capacitors. I snipped out the capacitors and turned the power on again.

 

However, once the capacitors in the track were gone, every loco acted exactly the same as before, each one that usually took a bit of nudging still did and so on and now there was interference on the telly downstairs. I can't understand why, as don't all the decoders have built in capacitors, hence why the track capacitors needed to be cut out? Not sure if there is any difference, but I use a mixture of Hornby, Gaugemaster and Bachmann decoders. All the motors on my layout (all locos and one turntable) have decoders fitted.

 

Can anyone suggest why there is interference and what I can do to sort it please? Also why my locos don't work any differently?

 

Thanks

[morairamike]

Yes I also find that my DCC layout interferes with my TV. I don't have power clips on my kayout, as I use a power buss soldered directly to each individual rail. I have a TV in my train room which pixelates when the loco run. Before anyone says so yes I use an anti surge extension socket to provide the power to the layout users. The TV is plugged directly into the same ring main but in the wall. 

I use a loft serial and an aerial booster, again in the same ring main.

I have noted that downstairs, different ring main, that when the TV is on in the kitchen and the the fridge door is opened or shut the internal light going on/off also pixelates the kitchen TV.

The house installation is 10 years old, which was when the house was built.