New Broadway Paragon 4 decoder close up

[GM50 4164]

Here is a close up of their new Paragon 4 decoder from my SW7. From what I can tell from pictures on Mark's, http://www.spookshow.net/locos.html page is the larger, what I'm guessing, capacitor behind the front headlight board. I cannot easily determine which is positive and negative as there are no markings. There is quite a bit more room inside of the cab if anyone wanted to add more capacitance.

[peteski]

The large orange component is in fact a SMD tantalum capacitor  It doesn't seem to have polarity marking because (to maximize capacitance per square millimeter) these do not have a typical epoxy resin case with solder pads.  If you notice, one metal end has a dimple in the center. That indicates the positive side.  To be syre you can also put the loco (with the shall removed) on a live DCC track, then connect a DC voltmeter to the metal ends of the cap.  If the and the meter reads positive voltage, then you just identified which end is positive. It will also tell you the voltage across the cap.

Keep in mind that this might not be a "stay alive" cap you would see across the output of the decoder's bridge rectifier.  It might be a filter cap for some other internally generated voltage. In that case, attaching a keep-alive to it would not yield the results you are looking for.

Here is a handy photo taken from https://electronics.stackexchange.com/questions/35480/polarity-of-unmarked-smt-electrolytic-capacitor

[GM50 4164]

The large orange component is in fact a SMD tantalum capacitor  It doesn't seem to have polarity marking because (to maximize capacitance per square millimeter) these do not have a typical epoxy resin case with solder pads.  If you notice, one metal end has a dimple in the center. That indicates the positive side.  To be syre you can also put the loco (with the shall removed) on a live DCC track, then connect a DC voltmeter to the metal ends of the cap.  If the and the meter reads positive voltage, then you just identified which end is positive. It will also tell you the voltage across the cap.

Keep in mind that this might not be a "stay alive" cap you would see across the output of the decoder's bridge rectifier.  It might be a filter cap for some other internally generated voltage. In that case, attaching a keep-alive to it would not yield the results you are looking for.

Here is a handy photo taken from https://electronics.stackexchange.com/questions/35480/polarity-of-unmarked-smt-electrolytic-capacitor

I saw the dimple on the engineer's aside and thought that may be it. Comparing this decoder to their Paragon 3 decoder, this large cap appears to be the only new piece added. They do state that it has a cap to help it over dirty spots. If I were to add my own caps, could I add them to this one on the decoder or would you suggest removing it first?

[peteski]

Assuming that this is "the" capacitor right behind the bridge rectifier, you can leave it, and add more capacitors in parallel with it. Connecting anyt capacitors in parallel results in total capacitance being a sum of all the capacitors.

[Chris333]

Does that decoder have an antenna?

[reinhardtjh]

Does that decoder have an antenna?

That thick black wire in the photo.

[GM50 4164]

Does that decoder have an antenna?

Yes, this is the antenna for Broadway's Rolling Thunder system. Wireless audio system that goes under the layout.

[GM50 4164]

Assuming that this is "the" capacitor right behind the bridge rectifier, you can leave it, and add more capacitors in parallel with it. Connecting anyt capacitors in parallel results in total capacitance being a sum of all the capacitors.

Is there a way to determine the capacitance of the cap that Broadway used with this decoder? Or any cap for that matter?

[peteski]

Is there a way to determine the capacitance of the cap that Broadway used with this decoder? Or any cap for that matter?

Not without unsoldering it.  If out of the circuit, there are capacitance meters which could give you the capacitance (but not voltage rating).  That big orange cap is probably 220 uF, hopefully rated at 25V.  I doubt it is more than that.

[GM50 4164]

So far I have added one of the Iowa Scaled Engineering powerkeepers and it appears to have helped somewhat. I have also determined that 2 more poly caps can be placed on top of the oem cap. I'm wondering if i was to remove the Powerkeeper and just wire in caps like normal, not using the protection circuitry of the PK if that would make a difference.

After running my locomotives around the loop for a couple of hours, I've found the wheel wear is not consistent. 1 wheel on each truck is not making good contact to the rail, therefor not making good electrical contact! There is very little play in the wheels/axles. More like up and down movement so they don't shift with the unevenness of the rails. I pay particularly good attention to my trackwork when I'm laying it. I've always felt that good trackwork is key to N scales performance. Most of my stalling issues are at the, currently, un-powered frogs. All of my turnouts are scratch built using jigs so there isn't much issues with them unlike some other track brands that have slight raises in height of the guard rails and frogs. Anyway I'm rambling. I'm trying to devise a way to give the wheels more vertical movement inside the trucks. Hoping this will help with the lack of contact with those couple of wheels.