I have 2 BLI GS4’s. Like many others I had them on Pre-order. When they arrived one model I sent back because it was such a mess. I was sent a new one that was acceptable. When they first arrived I tested them on a 22" radius loop. They operated well, and noticed no issues. Back in the box they went.
This past week I finally set up a large enough section of my layout, that I can test locos on it. This is where I found some strange performance issues with my GS4’s. They both hum (very loudly) when I start to apply the throttle, the hum tends to go away as it starts to move. When I slow the engine down, the hum starts up again. It also seems to have jerky quality. At times it almost looks like it is going to stall as it begins to move forward. I have tested other BLI paragon 2 steamers on the same section of track and non of them exhibit these performance issues.
Is this a decoder issue? I believe I read somewhere that a BLI GS4 owner had to pull the paragon 2 decoder to get it operate correctly.
Some of my QSI decoders do that. A couple of my BLI steamers hum while the decoder slowly dials down the motor current to zero, but after the engine stops. That can take up to 20 seconds. What I do to stop if is just hit emergency stop. It’s a pain, but at least it is all 100% reliable. These are the QSI upgraded chips from 2006. I can’t speak for modern Paragon decoders or the last two main issues of QSI, their Revolution or Titan.
It has been suggested a number of times over the years, probably most often by Randy, to do a hard restore to factory defaults before you do anything with a new engine. Even I elect not to do it, but if I have problems with a decoder, it is often easiest to reset it, and then start over with adjustments to CV’s that pertain to your way of doing business. It might be worth doing for this one loco…start from a known reference point with a reset.
Yes it starts as the motor is winding down, then after it stops it takes a few seconds to go away.
It makes sense to do a reset. I’m also going to switch off the smoke unit to see if it has something to do with the hum. I also wonder if it has something to do with the DCC system. I am using an NCE Power Cab. I might take it to my LHS and test it on a digitrax.
The GS4 has a smoke unit in it and a fan. Is this what you might be hearing. I have two of the GS4’s and do not recall any hum except the smoke unit fan. It can be turned off by a CV or like I did, remove the small hatch between the smoke stack and the steam dome. There is a switch located below the hatch that turns off the smoke unit which over rides the CV.
It turns out that I use a Digitrax DB150 from a Super Empire Builder, and I still get the hum. I also still get the hum on the same two engines even after a full reset. It could be that there is a higher order of CV’s to adjust, but I have never bothered to investigate. Pressing the Emergency button is much quicker.
I ran my GS4 and some motor noise is present when the sound is turned down. It seems to be the back emf type of sound in the motor and the Emergency button probably cancels the motor drive and back emf or whatever. This could be adjusted out with Cv’s but then the model might not run well at slow speeds.
I just tested a BLI paragon 2 dreyfuss hudson and the same thing happens. CZ, I agree I think it has something to do with BEMF. I noticed that the heavier the load and while going up grades the hum amplifies. Whats funny is the my P2 Y6B doesnt do this, nor does my P2 SW7.
I am going to call BLI on Monday to ask them about it.
I have an idea about how to trouble shoot if its the decoder. Since all BLI’s use the same harness, I was thinking of plugging in the Y6B Paragon 2 tender/decoder into one off the humming engines. This would show if its specific to the decoder.
If it still hums, I would then plug in a non paragon 2 tender. Maybe from a TTT. I think these have QSI with no BEMF. Then I would know for sure if its the decoder or not. My only concern is if I can plug in this tender without damaging the engine. I am mostly concerned about the smoke unit. So I figure I can switch it off and it should be a non issue. Any opinions on this? Should it work?
It’s all HO scale, same connector, same power to the rails… the only caveat is that the output to the lights and speakers are within a safe range. Very likely, but it would be good to verify. Personally, I would use a tender with the chuff set at articulated, and watch the household critters perk up their ears over the difference. [(-D]
I now think its the fan… I turned off BEMF, and the sound continued. I also tried a different Paragon 2 decoder/tender. The sound is still there. The fan is still operating even though the smoke unit is switched off. The fan kicks on once the loco begins to move. Listening closely its coming from the nose of the loco. Does anyone know if a CV to turn off the fan is available?
Yes, it’s in the manual. I don’t know which one it is, but there is definitely a CV to tun off the smoke unit. I wonder if you have burned yours out inadvertently.
Guys, Using F7 and Turning the smoke units hard switch shuts off the smoke heater unit. But not the fan. The fan is still operating. You can here is spin with every chuff.
According to the BLI tech manual for paragon 2. Page 178 CV234 Smoke Unit Fan Chuff Time will alter the fans on time. I think this is the CV that will shut it off. Values are from 0-255. Its set to 25.
CV235 controls the fan during idle. While Idle its almost off. Its set to 250, with a range of 0-255. These are the only two CVs that seem to control the fan.
I also found that you can also set CV246 to 0. This makes smoke unit power OFF at start-up. Smoke will not come on unless you press F7.