How exactly is the date code on Simplex devices supposed to be interpreted? For example, I have 2 4903-9236s, the date code on the label consisting of 3 letters. Have no idea at all how Simplex expects one to be able to know the date from just that.
I’m curious about this too, I have a 9236 with a date code of HSW.
The HSW date code means
H is the month (August)
S is the year (1998)
#1: Where did you learn this supposed formula from?
#2: How is “S” supposed to mean “1998”? (& while I determined that “H” would logically mean “August” from both being the 8th thing in the “things” they come from, I’m still not sure that this is how Simplex’s date codes are supposed to be interpreted)
#3: What does the “W” mean?
This is how I figured this out. I was paying close attention to the date code. I then thought it was useful to study and decode the date codes.
I knew the first letter was the month because there’s 12 months in a year.
A=January
B=February
C=March
D=April
E=May
F=June
G=July
H=August
I=September
J=October
K=November
L=December
As of for the 2nd Letter I knew that meant the year
O=1993-94
P=1994-95
Q=1995-96
R=1997
S=1998
T=1999
U=2000
Since the older Simplex 4903s were produced 1993-2000 and selectable replacements took place in November 2000. The 24 FPM Electromechanical Horn/Strobes took place between January-September 1994. The 60 FPM Electromechanical Horn/Strobes took place between September 1994-April 1998. The Electronic Horn/Strobes took place between April 1998-October 2000. The 24 FPM Strobes and Speaker/Strobes took place between January 1993-September 1994 and 60 FPM from September 1994-October 2000.
The Electromechanical Horn/Strobes, Speaker/Strobes and Remote Strobes that are 15CD are actually 15/75CD, though they seem much more dim and as for the 30CD models I think are actually 30/110CD. They seem a bit more bright than 30CD. I think the 110CD models are just 110CD though they seem more bright than that. Obviously all 15CD strobes are going to be quite dim and 110CD strobes are going to be very bright not just Simplex strobes. Normally I think 30CD is a little dim and 75CD is a bit bright, but it sometimes seems that Simplex and EST Edwards Strobes are brighter on those Candela settings.
I’m not sure any of what you said is actually true but okay (for now I’m just going to wait until someone provides absolute concrete proof of what Simplex’s date codes mean). You also did not explain what “W” means.
I don’t actually know what the W stands for. I think it may mean week or something like that.
Maybe, but given how the other two might indicate the exact year & month “W” directly standing for “week” wouldn’t make much sense (if it indicated said week of a particular month however that would make sense).
Also the bottom date codes of a Simplex alarm are never correct. For example seeing a Simplex 4904-9137 with a 7/95 at the bottom when the top date Code is written as FQW as an example. Not all 4904-9137s were made exactly in July 1995. They obviously had to be made in ALL months of 1995. That 7/95 is misleading and this was a complete mistake on Simplex’s end. If they put a more exact month at the bottom; that would’ve made it easier to understand when it was made. It’s more confusing with the mid 1990’s 4903s & 4904s as opposed to the models from the late 1990’s. Obviously if the alarm had the newer Simplex logo with the smaller S it would be a 1999-2006 model. Simplex then changed back to the Smaller S in 2024 on their 4903s. Maybe 7/95 meaning when they changed the tags on the 4904s but what does that actually tell us about the date code itself. I think the date Code FQW would tell us that the unit was made in 1996 & not 1995.
Is it possible that the “A” does not correspond to January but instead to the first month of the fiscal year? This would explain why O, P, and Q do not correspond to a single year.
Yep O Applies to 1994
P applies 1995
Q applies to 1996
R applies 1997
S applies 1998
T applies 1999
U applies 2000
I simply just don’t like how it says 2/93, 1/94, 8/94, 9/94, 4/95 & 7/95 on Simplex Electromechanical Horn/Strobes & Horns, 4904 Strobes & Speakers & Speaker Strobes because that doesn’t actually specify the actual month week or day it was made so damn you Simplex. Those are only the revision dates NOT when the actual alarm was made. They at least changed the date codes to actual numbers & letters for 1996-98 EM 4903s & Speaker/Strobes. Alongside REV A B & C it would be helpful to have a Specified date.
Where did you get all that info from?
Wait seriously? Odd-as-heck decision by them if you ask me…
Well that’s good, but they honestly should have just done that from the start: really made no sense putting the date in a format incomprehensible to almost everyone.
What’s all that about exactly? (does that have anything to do with their candela indicators switching from symbols to text circles? (if the 4903-series lasted that long at least)
Any idea what “DTW”, “ESW”, “FSW”, & “HTW” could mean? These are the date codes on the 4903s I have currently.
DTW (April 1999, Weeks 13-17)
FSW (June 1998, Weeks 23-27)
ESW (May 1998, Weeks 18-22)
HTW (August 1999, Weeks 30-35)
Here’s some samples of what I wished Simplex date Codes would look more like
4903-9220 Made Friday, September 9, 1994 (Week 36). This is jjinc24’s 4903-9220 (Which sounds bad by the way & this horn is really not that loud other than sounding very raspy). The strobe also makes a hella loud beeping sound & flashes not too fast.
4904-9145 Made Tuesday, July 4, 1995 (AKA Independence Day, Week 27). This is a 4904-9145 that midtnindustrial is selling on eBay.
4903-9305 Made Sunday, October 29, 2000 (Week 43). This is formerly sold by some eBay seller. This 4903-9305 is one of the newer ones before they switched out to the current selectable 4903-9149. With the newer Simplex logo & ‘110CD’ sticker
4903-9215 Made Saturday, November 11, 1995 (AKA Veteran’s Day, 45th Week). Another former eBay listing.
4903-9238 Made Sunday, October 31, 1999 (AKA Halloween, 43rd Week). jjinc24’s 4903-9238 which I have never seen in action before. This has the newer Simplex logo but still has the orange triangle to indicate the strobe is 110CD. I’m pretty sure this one flashes at around the flash rate that it should since it’s a 1999 strobe.
4904-9136 made Friday, October 15, 1999 (41st Week). This 4904-9136 is being sold by eBay seller Imperial Building Materials (20126). A relatively newer -9136 due to the Simplex logo but still has the colored shape for 110CD. This one probably flashes at a more normal flash rate compared to earlier models.
4903-9217 made Thursday, September 26, 1996 (39th Week) Sold by eBay seller StuStop AKA Simplex Guy from decommissioning
4903-9217 made Thursday, November 24, 1994 (AKA Thanksgiving 1994, 47th Week). Brand new out of box but sold out.
4903-9218 made Wednesday, September 21, 1994 (38th Week). Sold by jgonzalez to Tice Arpey. This alarm is in very good condition but the horn sounds terrible. The horn is really not that loud. I would like to find a 1997 model of the 4903-9218 on eBay. I would bet the strobe makes a loud beep every time it flashes.
4903-9219 made Friday, November 4, 1994 (44th Week). Sold by an eBay seller not too long ago. I’m going to guess this unit doesn’t sound too good due to the old age & the strobe makes that really annoying beeping sound but probably doesn’t flash that fast.
4903-9217 made 43rd Week 1995 (Sunday, October 29, 1995). Sold by Ernie Toronado.
4903-9219 made 1st week 1995 (Monday, January 2, 1995). Sold by eBay seller jjinc24 recently with a cracked housing. It might sound raspy.
4904-9145 made Monday, July 25, 1994 (30th Week). An eBay seller is selling this alongside other simplex & Edwards EST Fire Alarms
4903-9146 made Sunday, October 9, 1994 (40th Week) being sold by eBay seller hh1111. These units are very old, listing is overpriced & the alarms are very dirty looking. He will not allow you to choose your quantity either. I bet these ones don’t flash that fast but are probably the loud beeping versions of the strobe, plus they are low intensity 15CD strobes.
4903-9145 made Sunday, July 31, 1994 (30th Week). This is a very rare Speaker/Strobe being sold by eBay seller Integrity Electric and Machine (6360). This is the vertical mounted version of the 4903-9144 & is a 110CD counterpart of the 4903-9147. This one is High Intensity which is cool!
4903-9215 made Thursday, March 30, 1995 (13th Week). This was sold on eBay a long time ago. This may sound raspy.
4903-9301 made Friday, October 1, 1999 (39th Week). meemsales is the person selling this alarm on eBay. This is a SmartSync version of the 4903-9146.
4903-9219 made Tuesday, September 5, 1995 (36th Week). jjinc24’s 4903-9219. I think this one will probably flash fast when tested.
4903-9147 made Wednesday, August 31, 1994 (35th Week). Was sold on eBay a long time ago. Vertical version of the -9146 obviously. Probably a very noisy beeping strobe flashes relatively slow.
4903-9146 made Monday, July 17, 2000 (29th Week). Again, this was sold on eBay a while ago. This appears to be a newer -9146 with the newer Simplex logo & transition from colored shape to candela sticker. This one probably flashes at the rate it should.
4903-9146 made Thursday, July 25, 1996 (30th Week). Was sold on eBay awhile ago. It said 7/95 at the bottom so I fixed it to give a more time accurate date. This unit I bet flashes pretty fast. Faster than it should. They should be flashing at 60 FPM.
4903-9405 made Sunday, December 25, 1994 (AKA Christmas, 51st Week). The SmartSync version of the 4903-9217. I REALLY want to find a -9405 again on eBay someday. Since this is the 94’ model it probably won’t sound that great as the horn is powered up. It would be like a really raspy perfectly timed version of the Wheelock 7002T.
Alright, thanks! (not sure why you didn’t list them alongside the previous lists you laid out but thanks)
Where are you getting this date code info from though? (asked you this previously & you didn’t answer it) Prior to now seemingly nobody had any idea how Simplex’s 3-letter date codes were supposed to be interpreted, but now you seem to suddenly have near-company knowledge of them!
Here’s another Sample; This one takes place of a really old 4903-9217 from the year 1994. Again, the horn probably sounds like crap on this unit from age. It’s still amazing regardless! Probably not that loud & very raspy. You can expect that from the 1994 horns honestly. It looked pretty clean from the front but from the sides it has a bit of olive paint from when it was installed & pulled from a working system.
I made a date code that was a little easier to understand such as ‘3994’ rather than the date Code ‘AP’ like it was in the picture. I made a realistic date of Friday, September 30, 1994. I think this is probably a strobe that will make a very loud beep every time the strobe flashes
Here’s a realistic simulation of a Simplex 4903-9219 that was made the exact same day as the 9217 listed up above
I always watch carefully the letters and if the numbers at the bottom change then that likely means it is an improved version of a model that already existed at the time
Actually I figured out how to interpret a date Code on an older 4904-9137 strobe
Take a look at the month year mold on the plastic! This 4904-9137 has a Date Code of FPW and it is from April 1995. In the form of a question, When was this Simplex 4904-9137 made?
A. September 1994
B. February 1995
C. April 1995
D. June 1995
And yet, the correct answer is C!
I also figured out how to find a date of a Simplex 4903 and I will show you (The electronic horn/strobe likely has a more accurate date)
