This Simplex 4903 that I have in my collection is what I believe is a misprint or a prototype of some kind. It has the model of 4903-9136. I’ll post pictures in the future, but does anyone have an explanation for it? Thx
I don’t see it in the Simplex Model checker, but here’s another thread with someone else with the same model: About my simplex 4903-9136
That’s actually my post I made a few years ago on it. I did find information of it though. It was replaced by the 4903-9147. Here’s additional information. It’s 15CD, a vertical mounted variant, currently disassembled in terms of the speaker and strobe, and has an A at the end of the 521-780, assuming it’s an ID of some kind
Those are really rare! I feel like I’ve seen 4903-9136 Speaker/Strobes once in public inside of the Boston Prudential Center shops built in 1993 while the Prudential Tower itself opened in 1965. Also on eBay they have a Simplex 4903-9145 Speaker/Strobe (an NIB one) which is like the 4903-9147, only that it is 110CD. It also has a 60 Flash per minute flash rate. 4903, not 4904. Both the 4903-9145 & 4904-9145 have horizontal 110CD 60 flash per minute free strobes.
Here’s a link to 4903-9145 on eBay;
It’s really expensive but really rare
Here’s some long-lasting images
Note: These are not my images so I give full credits to the eBay seller “Integrity Electric and Machine (6369)”
I wonder if the 4903-9145 replaced a similar vertical mounted 110CD counterpart to the 4903-9136 (wonder what that could be). This isn’t even a mistake either! It’s real! However the interesting thing is it still has the 521-780 reference like the 4903-9136 in the photo (however they would’ve changed to 521-785 references probably beginning in date code AP which I arguably want to say is the “real” September 1994)
I’m pretty sure Simplex also made the 4903-9143 which I’m pretty sure is a 30CD version, also vertical mount
Then there’s probably some 70V versions of the vertical 4903 speaker/strobes in the 4903-917X series as well as sync versions of these vertical 4903s in the 4903-930X (25V) & 933X (70V) series
Simplex probably had made a 70V counterpart to the 4903-9136. There’s 4903-9109 which is 70VRMS & this got replaced by the 4903-9174. The 4903-9107 is 25VRMS & this got replaced by the 4903-9144.
those look sus… 
Your comment is very sus-picious, 
!
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Okay, let’s stay on topic. We should be talking about obscure (not known to human) 4903s such as units like 4903-9136 & 4903-9145 which are essentially different variants of/like the 4903-9147
Here’s a list of obscure 4903 models I know so far
4903-9136 - 24 Flashes Per Minute, 15CD, 25VRMS Speaker, Red Vertical
4903-9145 - 60 Flashes Per Minute, 110CD, 25VRMS Speaker, Red Vertical
4903-9109 - 24 Flashes Per Minute, 110CD, 70VRMS Speaker, Red Horizontal
Related not obscure models include 4903-9107, 4903-9144, 4903-9147 & 4903-9174
It makes a lot of sense that the 4903-9145 is a red vertical mounted 110CD 25VRMS Speaker/Strobe since they obviously have 4903-9142 (30CD), 4903-9144 (110CD), 4903-9146 (15CD) & 4903-9147 (15CD). 4903-9145 is right in between 9144 & 9146 and since 9145 & 9147 are odd numbers that means they are vertical mounted while even numbers are horizontal mounted. Now since I see the pattern, they probably have had to make a 4903-9143 Speaker/Strobe, a red vertical mounted 30CD Speaker/Strobe. I feel like 70VRMS vertical mounted speaker/strobes would be in the 4903-917X series. As of now, they’re obscure.
Most of the 4903-91XX speakers have completely Free Run strobes
I wonder if we’d be able to figure out any other speaker visibles & horn visibles
I also forgot to mention another obscure model I figured out from a former eBay listing; the 4903-9155
Features of the 4903-9155:
Mounting: White Round Ceiling Mount
Strobe operation: 1hZ Free Run
Strobe intensity: 15CD (Not very bright)
Volts RMS: 25
This looks like a 4906-9154 except much older. It’s got the thinner & taller fire lettering. 4903-9155s are extremely rare
When the fire alarm is sus
Don’t start please, it’s getting annoying.
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Here’s some key concepts I’ve learned from the 4903 Speaker/Strobe Series
Since 60FPM 4903s start at 4903-9142 and end at 4903-9178 we’ll have to figure out a pattern from this series
4903-9142 - 25VRMS, 30CD, Free Run, Red Horizontal
4903-9143 - 25VRMS, 30CD, Free Run, Red Vertical
4903-9144 - 25VRMS, 110CD, Free Run, Red Horizontal
4903-9145 - 25VRMS, 110CD, Free Run, Red Vertical
4903-9146 - 25VRMS, 15CD, Free Run, Red Horizontal
4903-9147 - 25VRMS, 15CD, Free Run, Red Vertical
These are all 25VRMS Speaker/Strobes with the pattern being Red Horizontal, Red Vertical & the pattern repeats 3 times. The mid candela models come first, then the high candela models & then lastly is the low candela models. Obviously the Even Numbers are Red Horizontal units & the Odd Numbers are Red Vertical Mount units. 2 & 3 both start with letter T, 4 & 5 both start with letter F, 6 & 7 both start with letter S. I gotta say this is one of the coolest model number patterns
4903-9167 - 25VRMS, 15CD, Free Run, White Horizontal
4903-9168 - 70VRMS, 15CD, Free Run, Red Horizontal
4903-9170 - 25VRMS, 30CD, Free Run, White Horizontal
4903-9171 - 70VRMS, 30CD, Free Run, Red Horizontal
4903-9173 - 25VRMS, 110CD, Free Run, White Horizontal
4903-9174 - 70VRMS, 110CD, Free Run, Red Horizontal
Hey but wait, models 4903-9169, 4903-9172 & 4903-9175 we don’t know about but what features do they have? They obviously have to be 70VRMS Speaker/Strobes! But are they White Horizontal or Red Vertical?
Okay, the model number 4903-9169 is close to the 4903-9167 & 4903-9168 so it has to be a White Horizontal unit with a 70VRMS Speaker & a 15CD Free Run Strobe
The model number 4903-9172 is close to the 4903-9170 & 4903-9171 so it has to be a White Horizontal unit with a 70VRMS Speaker & a 30CD Free Run Strobe
The model number 4903-9175 is close to the 4903-9173 & 4903-9174 so it has to be a White Horizontal unit with a 70VRMS Speaker & a 110CD Free Run Strobe
The pattern here is White Horizontal 25VRMS, Red Horizontal 70VRMS, White Horizontal 70VRMS repeating 3 times. The 3 lowest numbers in the 4903-916X series are 15CD & the medium & high 4903-917X models are 30CD & 110CD ratings respectively. The ones in the middle are 30CD & the ones at the end are 110CD. This fulfills the requirement of 25VRMS & 70VRMS Horizontal Red/White Units with Free Run Strobes. This also I gotta say is one of the coolest model number patterns also.
The model numbers 4903-9179 to 9192 apply to Simplex rebranded Wheelock Speaker/Strobes
Now we’re missing model numbers 4903-9176, 4903-9177 & 4903-9178 but what are these? These also have to be 70VRMS Speaker/Strobes that are either White Horizontal or Red Vertical
These would have to be the Red Vertical Mounted Units with the 70VRMS Speakers
The Higher the 4903-917X model number is, the higher the candela will be
4903-9176 - 70VRMS, 15CD, Free Run, Red Vertical
4903-9177 - 70VRMS, 30CD, Free Run, Red Vertical
4903-9178 - 70VRMS, 110CD, Free Run, Red Vertical
4903-9106 is actually a 24 Flashes Per Minute Speaker/Strobe that has a 25VRMS Speaker & 15CD Strobe. It was replaced by the 4903-9146. So for those of you thinking the 4903-9106 is a strobe plate, it’s not. It has been a Speaker/Strobe all along 1993-94. That means the strobe plate with the 100CD strobe was called the 4903-9105 all along. I’m sorry I have to break it to you. At this point I just wanna know the 30CD model of the 4903 24FPM Speaker/Strobes with the 25VRMS Speaker & Red Horizontal Mounting Style. Also I want to know what the 70VRMS Counterpart of the 4903-9106 is, the one that got replaced by the 4903-9168.
24FPM 4903s we still haven’t figured out yet
4903-9108, 4903-9110 to 4903-9135, 4903-9137 to 4903-9141. All of these model numbers should be 24FPM Pre-ADA Speaker/Strobes which means model numbers like 4903-9142 should’ve replaced a 24FPM 30CD 25VRMS Speaker/Strobe with a Red Horizontal Mounting style, but which one?
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