QSI in an Atlas Dash8-40CW


santafe49
 

I have an Atlas Master Dash8-40CW from the June 2004 release, with factory installed QSI decoder. The sound has gotten kind of crackly and i suppose the speaker/s have cracked?
Would anyone happen to know the Ohm load of the speakers? 4, 8, or 16 ohms?
Haven't opened it up but thought i would be get ahead of the game if someone had the answer.
Thanks in advance.
--
James St. Clair


Barry Yankolonis
 

Hi James,
From my recollection, think all the QSI decoders came with 8 ohm speakers.
Yank


ffbrehm@...
 

Hi James,

They are 8 ohm. They are slightly larger than 1” I believe but not exactly sure of the size.

Frank Brehm

 

From: QSIndustries@groups.io <QSIndustries@groups.io> On Behalf Of santafe49 via groups.io
Sent: Thursday, April 1, 2021 5:03 PM
To: QSIndustries@groups.io
Subject: [QSIndustries] QSI in an Atlas Dash8-40CW

 

I have an Atlas Master Dash8-40CW from the June 2004 release, with factory installed QSI decoder. The sound has gotten kind of crackly and i suppose the speaker/s have cracked?
Would anyone happen to know the Ohm load of the speakers? 4, 8, or 16 ohms?
Haven't opened it up but thought i would be get ahead of the game if someone had the answer.
Thanks in advance.
--
James St. Clair


Bob Waldele
 

James

If I recall correctly (without benefit of opening up one of my Atlas Gold series units)

The decoder is either a Q1 (Rev.6) or Q1a (Rev.7) version.  In the road switchers they used an A-frame cast into the rear (long hood) weight block and it is fitted with two (2) 28mm 8Ohm 0.5W speakers wired in series; the “net” effect is a 16Ohm 1W speaker equivalent.  These speakers have a low-profile (shallow) cone so the back of the speaker does not vibrate against the carbody.  These “special” speakers are readily through most suppliers (Tony’s, Litchfield, MB Klein, etc.).

Given the age of these units, it is possible that one of the wire connections might be coming loose causing the intermittent or static; examine the solder connections at the speakers and also the wire connections at the decoder (one or more broken strands?).  It is also possible – as you suspect – the speaker may be showing its age (I have had both of these happen)

Good luck.

Bob.W


Paul B/Indy
 

FWIW, these were a Rev 6 when new out of the box.  The Rev 7 was available as a replacement plug-in chip for these engines.

Paul B/Indy


On Apr 2, 2021, at 12:18 AM, Bob Waldele <rwaldele@...> wrote:

James
If I recall correctly (without benefit of opening up one of my Atlas Gold series units)
The decoder is either a Q1 (Rev.6) or Q1a (Rev.7) version.  In the road switchers they used an A-frame cast into the rear (long hood) weight block and it is fitted with two (2) 28mm 8Ohm 0.5W speakers wired in series; the “net” effect is a 16Ohm 1W speaker equivalent.  These speakers have a low-profile (shallow) cone so the back of the speaker does not vibrate against the carbody.  These “special” speakers are readily through most suppliers (Tony’s, Litchfield, MB Klein, etc.).
Given the age of these units, it is possible that one of the wire connections might be coming loose causing the intermittent or static; examine the solder connections at the speakers and also the wire connections at the decoder (one or more broken strands?).  It is also possible – as you suspect – the speaker may be showing its age (I have had both of these happen)
Good luck.
Bob.W


Nick
 

James,

The Atlas Gold series were (for me) GREAT locos. I still own 2 of the FM Trainmasters and other than dirty wheel problems, they still work and sound  great.

Tony's carried the original speakers and they will work fine as replacements. I have also replaced some of the original speakers, in other locos, with small sugar cube speakers with surprising results. "Bass" response with the small enclosures is remarkable compared to the "compact" speakers available when these locos were released almost 20 years ago. Don't be afraid to try them . Modifications in mounting them is needed but they do work well.

As Paul mentioned, the original decoders were the "crippled" versions thanks to Mike's Train House's frivolous lawsuit back then. After the suit was dismissed, the upgrade chips and programmer were released. The old chips had a LOT of problems like no BEMF, loss of programming after a short circuit, running away after a short circuit, and more than can be addressed in this forum.The $30.00 price for the upgrade is well worth the investment. It also provides a way to upgrade the sound file if you own the QSI programmer or know someone that does.

Good luck,
Nick Kulp