BLI locos stalling with sound on

[bobthebear]

Has anybody else had this problem.
I have 3 sets of BLI locos, 2 sets of E7s and a set of PAs.
The PAs struggle through Peco double slips, all correctly wired, with the sound on. Turn the sound off and they are fine. Took trucks apart and checked for dirt and electrical continuity and all is fine. Reduced the sound level on one and that is now OK, but the other has to have the sound off. Track is clean and all other sound locos eg. Athearn FP45s and the BLI E7s and Digitrax equipped ones don't hesitate.
Tempted to make up some jumper wires to the dummy B unit as that already has pickups.
Odd.
Cheers, Bob.

[victor miranda]

you are running them on DCC ?

I can think of one maybe and that is a DC thing.

If one loco hits a section that has a higher resistance
the loco may slow and the voltage for the sound may drop below
some threshold...

a power level thing.  as power needs go up
small changes in resistance are more significant.

I want that to be more help.

victor

[bobthebear]

Hi Victor.
I'm running DCC, and will borrow my mates RRamp meter sometime soon to test the d.slip which is brand new.
I agree it is probably a voltage or current drop, but strange that only one loco out of 9 heavy draw current locos is affected.
Cheers, Bob.

[kewatin]

 hi bob the bear,
sir i am experiencing the same problem you are with my bl emd e8. i had sent it back for warranty and they said they replaced the decoder but it still stalls at 3 spots&dies on my layout. which is dcc. i use ance powercab and kato track.also my track&wheels are clean.also my other locos  including my new bachmann sound equipped berk run perfectly with no problems. i would not have thought to turn off the sound on my bl e8 till i read your post,&when i tried it, it does run perfectly fine.i am really confused &disappointed with this product. i also today sent a query to their service dept but don't expect much.this loco is getting to the poit that it is eating shipping costs from canada to florida .i sure hope victor  or some one else has a possible fix for this problem. also my powercab shows .09 to .013 amps when running ,wether sound is on or not.
regards&later kewatin

[Cajonpassfan]

Hmm, that is a really odd phenomenon. I have about a dozen BLI sound/powered units from various runs, and while finicky, only the last run of PA's had electrical pickup problems. I never thought of trying to see if the problem diminishes with sound off. I solved the issue (mostly) with additional weight, as they are relatively light, and may yet add a hard wired connection between the units. Curious...
Otto K.

[Santa Fe Guy]

I'm surprised also. My BLI E8 runs sweetly on my DCC powered SFRSD. Most of my operators want to run it just for the sound.
I'm thinking your layout is lacking enough grunt to power the sound decoder, hence with sound turned off it runs okay.
Hope you find a fix.
Rod.

[peteski]

I also find this very odd.  The sound decoder consumes more current than a non-sound decoder whether the sound is muted or full blast.   The audio amplifier, even if it was cranked up full blast, would dissipate probably around 1W of extra power. I suspect that it is around 0.5W or less (with the puny speaker we used in N scale).  So when sound is muted, the current consumed by the loco would probably be between 40 and 90mA different with the speaker on or muted.  That is less current than is consumed by the loco's motor.   This is all just an educated guess but I suspect that my calculations are correct.  Would consuming 40-90mA less or more make enough difference to have the loco stalling or running smoothly?

[victor miranda]

hi peteski,

thank you.  you have give me a way to say this without looking nutty....

the issue is the total amount of current.

ok picture this add power to an pair of rails and apply power.
take a loco and send it down the rails
at some point the loco will stop because the resistance
in the rails has consumed all the power.

how far will two identical locos go?

this is the issue the sound unit locos face.
they depend on the voltage staying above a certain level
and if anything else add a little resistance (or a lot)
the lack of power (additional resistance uses power...) causes the sound unit to drop out.

one think I can tell you is that n-scale locos pick-ups are a little variable in their
resistance also. most times is it a few ohms... I see 1.4 ohms a lot.
and I see slowdowns that are not stalls... increased resistance?

I have to run
later

victor

[peteski]

Victor, since he is running these in DCC, the track voltage is a constant full DCC voltage (12-14V)  there would have to be rather larger drop to make the decoder stutter like that.

If he was running on DC and he wasn't running them at full throttle, that would be a different thing, but here I just don't see how a 6V drop can occur (I suspect it would take 6V drop from the full DCC voltage to make the decoder shut down).

[victor miranda]

ok, I agree it would take a rather large drop.

now... take some time and think about how to get that to happen.
'cause there is no other explanation.

the problems can be additional...

do the HO guys have these problems?

[peteski]

'cause there is no other explanation.

Um, maybe there is another explanation?  Like a decoder what is not 100% up to snuff (to use a highly technical jargon) and it is very sensitive to even small voltage drops (the type you would expect when crossing turnouts).

[bobthebear]

Thanks Guys for the feedback so far. And at least, Kewatin, I'm not alone in this!
 My Mate is coming Thursday with the RRamp meter, so I will update you after his visit. As I'm in UK, I don't really want to send locos over "the pond" to be looked at if I can sort this "in house".
Cheers Guys.

[kewatin]

KEWATIN here,
 gentlemen, i cannot thank you enough for your input,being new to this forum ,but old in age the help is really appreciated. in my case my layout is 10x6  L shaped with feeders dropped every 3 ft with the stalling taking place on straight section after leaving 22 '' radius curve and the same on the other end of layout.i even dropped in extra feeders in the problematic areas with still no resolve.what i do not understand is why all my other 14 locos do not have a problem including my 2 other sound equipped locos from another mfg.
 regards&later  KEWATIN

[Lemosteam]

is there any elevation in the rails from one section to the next that could be causing one or more of the wheels to come off the track?  Just a flyer here!

[davefoxx]

is there any elevation in the rails from one section to the next that could be causing one or more of the wheels to come off the track?  Just a flyer here!

The traction tires on the rear truck of BLI's E7s aggravate this problem.  I don't know if the PAs are similar.  John Sing has posted information on the 'net about replacing the wheelset on the E unit with a non-traction tire set that he obtained directly from BLI.  Would the PA benefit from this modification?

DFF