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
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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. Fun fact; the 25VRMS Speaker/Strobes follow the same model numbering pattern as the electromechanical horn/strobes (same goes for the sync models too). The 9143 & 9145 are 73 model numbers apart from the 9216 & 9218 (which are the electromechanical horn counterparts), therefore this logic applies for the 25VRMS Speaker/Strobes as well
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
Yes, the 4903–9176 is a 70VRMS counterpart of the 4903–9147 allowing for less signal loss over longer distances compared to the 4903–9147
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?
Since we know the 4903 25VRMS Speaker/Strobes follow the same model numbering system as the electromechanical horn/strobes we’ll take a look at the 4903–93XX Synchronized Speaker/Strobes
4903–9301; This is a 25VRMS Red Horizontal 15CD Model
4903–9303; This is a 25VRMS Red Horizontal 30CD Model
4903–9305; This is a 25VRMS Red Horizontal 110CD Model
That means the vertical mounted models are 4903–9302 (15CD), 4903–9304 (30CD) & 4903–9306 (110CD)
The 4903–9302 is a SmartSync Version of the 4903–9147. The 4903–9306 is the SmartSync version of the 4903–9147s so called long lost 110CD brother, the 4903–9145 (the 25VRMS speaker version of the 4903–9218).
Now it appears the 4903 70VRMS Red Horizontal Speaker/Strobe Series in the 93XX Models follows the same logic as the Free Run 91XX Counterparts
4903–9326; This is a Red Horizontal 70VRMS 15CD Speaker/Strobe
4903–9329; This is a Red Horizontal 70VRMS 30CD Speaker/Strobe
4903–9332; This is a Red Horizontal 70VRMS 110CD Speaker/Strobe
Now wait; We introduced the White Horizontal Synchronized 4903 Speaker/Strobes!
4903–9325 (25VRMS) & 4903–9327 (70VRMS); 15CD, White Horizontal
4903–9328 (25VRMS) & 4903–9330 (70VRMS); 30CD, White Horizontal
4903–9331 (25VRMS) & 4903–9333 (70VRMS); 110CD, White Horizontal
Well we are not done yet, we are missing 3 model numbers; this would apply to the Red Synchronized Vertical Mounted 70VRMS Speaker/Strobes!
4903–9334; This is 15CD, 70VRMS, Red Vertical
4903–9335; This is 30CD, 70VRMS Red Vertical
4903–9336; This is 110CD, 70VRMS Red Vertical
That satisfies the 4903 1hZ Speaker/Strobe Series!
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I bet the 9137 and 9138 are the 30 and 110cd counterparts of the 9136, while the 9139 to 9141 follow the same pattern, but are horizontal.
I kind of think they may be 70V Counterparts in the same vertical mounting style but I’m unsure. I wonder if Simplex made white 24 flash per minute models but they’re probably exceptionally rare. The 4903-9106 & 9107 are Red Horizontal units & I wonder if the 4903-9108 is (it may be a 30CD Version) since the 4903-9106 is 15CD & 4903-9107 is 110CD. The 4903-9109 is also Horizontal but it has a 70V Speaker instead of 25V & the strobe is 110CD.
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