Keep Alives?

[Peachymike]

Decided that I would like to install a couple sound decoders to see it I actually like it or not. Given the issues with the sound around stalls I thought it would be prudent to install some kind of keep alives, and I wondered what others are using and what their thoughts on them are. These would be going in n scale, and I have a mill so I can make room to some degree, but with a decoder, speaker and enclosure, it would seem to be a challenge to get much capacity in. So what have you done and what would you do differently?
Thanks
Mike

[woodone]

You are going to be hard pressed to find a Keep-Alive that will fit into a N scale locomotive.
You may be able to install a surface mount capacitor or two to help keep the decoder alive.
Use a pair of 220 uF 20 volt caps , that should help

[Steveruger45]

Iowa Scaled Engineering makes a ready made small power keeper.
https://www.iascaled.com/store/CKT-DCCSA

[John]

Iowa Scaled Engineering makes a ready made small power keeper.
https://www.iascaled.com/store/CKT-DCCSA

I put one of these into a P42 --- it does help a little

[Cajonpassfan]

I put one of these into a P42 --- it does help a little

Hmm, it does help "a little"? Worth the trouble or not?
Thanks, I have a couple sitting on my desk...
Otto

[John]

Hmm, it does help "a little"? Worth the trouble or not?
Thanks, I have a couple sitting on my desk...
Otto

I haven't run the one loco in quite a while - so I don't really have anything but memory to go on .. but I did notice less drop outs on the same stretch of track after I put it into the locomotive -- it certainly won't power it down the track like some of the HO keep alives do ..

[kiwi_bnsf]

I can recommend a couple of off-the-shelf options for N scale installs where space is at a premium.

My current favourite is the TCS KA-N1  https://www.tcsdcc.com/product-page/ka-n1

These are the smallest commercially available keep alive circuits that I've come across at only 6.6mm x 9.2mm x 3.5mm. I use these in a 3D printed holder for my Scale Trains Dash 9s where there is very limited clearance above the motor universal shafts:



(photo was taken before wires terminated and Kapton tape added).


I also have a large number of the Iowa Scale Engineering Run-N-Smooth Power Keepers  https://www.iascaled.com/store/ModelRailroad/Run-N-Smooth/CKT-DCCSA

These work great where there is a bit more room for the install (9.1mm x 10.4mm x 4.65mm).

ISE Run-N-Smooth installed in the milled front-upper section of a Kato SD40-2 Mid Production (fits under an ESU 58741 Kato drop-in decoder):




ISE Run-N-Smooth installed in the milled fuel tank of Kato SD40-2 Early:





With only 940-100 microFarads, these options might not seem sufficient, but my experience with operations and sound is that they make a significant improvement to reliability.

On relatively clean track and turnouts with powered frogs, sound dropouts become almost non-existent. For four axle locos and sound, a keep alive really is a must. I can run up and down yard ladders all day without any annoying sound drop outs.

Hope this info helps. Cheers

[GaryHinshaw]

Another vote for the KA-N1.  I have not (yet) used them with sound decoders, but I have been pairing them with a LokPilot Micro and the results are fantastic.  Super smooth with few if any stalls.

[Peachymike]

Thanks Gentlemen, exactly the sort of info I was looking for. As noted the space available leaves us with pretty limited options. All I was hoping for was to smooth things out. It’s irritating to have a unit stall, but I can imagine the whole restart sequence would ruin the effect. Don’t really want to spend $150+ for a decoder only turn the sound off!