This one is interesting. It appears to have used the platform as the FS Twinsonic but used it's Code 3 internals. Did Federal knowingly allow them to do that? There also was a rotor variant probably later on. When was it discontinued also it seems like it peaked slightly after the Twinsonic peak, seems more early 80ish. Seemed like a cool bar that in some ways bested the Twinsonic.
Code 3 SD history and evolution
- Thread starter 1968
- Start date
Maxim2Eng
Supporting Donor
Way back when…the VFD I was on had a brush truck with a 12X and a pumper with an SD. The 12X was fully synchronized (both sides) whereas the SD was not. The assembly of the SD was, essentially, two independent mini bars on a speaker tray. The SD flash pattern was random and changing while in use, which many of us didn’t like as well as the 12X. They only looked similar when not activated, so I guess FedSig didn’t think it was worth the trouble to do anything, especially since the SD had 4 more lamps and a motor than the 12X…this during a transition to a heightened awareness of amp usage on emergency vehicles.
JohnMarcson
Administrator
The SD was really just the jumping off point for the XL9000. They basically shared the same internals from the sealed beam era to the independent rotator era. Many other companies had "box shaped bars", so it was more of a standard package in the early days. The wedge shaped XL was meant to really push back at the standard "box bar" idea.
Stampeed Valkyrie
Member
There are 3 generations of SD bar,
SD overview..
youtube.com
1st Generation..
Had unique lamp holders.. reminds me of the same type of holders found in some Grote beacons.
1st Gen minibar..
2nd Generation..
This is where the internals started being the same as the XL9K series bars. Some internals.. but not ALL could be swapped between the 2 series.
2nd Gen minibar..
3rd Generation..
This is where the sealed beam bars were phased out, rotators were now the same as found on the XL5K series bars.
Other the the same square or rectangular shape, nothing between the SD and the Twinsonic bars are the same. As to which one is better? Personal preference, they have grown on me I find them more interesting to tinker with then Twinsonic bars.
SD overview..
Code 3 SD Bar Overview
Keeping the informational videos going on vintage lighting. This time I am talking about a Code 3 SD bar.. Basic how to information, and things worth no...
youtube.com
1st Generation..
Had unique lamp holders.. reminds me of the same type of holders found in some Grote beacons.
1st Gen minibar..
2nd Generation..
This is where the internals started being the same as the XL9K series bars. Some internals.. but not ALL could be swapped between the 2 series.
2nd Gen minibar..
3rd Generation..
This is where the sealed beam bars were phased out, rotators were now the same as found on the XL5K series bars.
Other the the same square or rectangular shape, nothing between the SD and the Twinsonic bars are the same. As to which one is better? Personal preference, they have grown on me I find them more interesting to tinker with then Twinsonic bars.
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This!
StampeedValkrie has done an outstanding job of displaying the evolution of the PSE/Code 3/Force 4 SD series of lightbars. Parts do not interchange between the Federal Signal TwinSonic and PSE/Code 3 SD bars.
They look similar and you can, with some irreversible modification, get the domes to swap, but that's about all. There have been instances where someone would take a worn out TwinSonic and swap in Force 4 SD or XL independent rotator assemblies, which is a way to breathe new life into a dead TwinSonic.
This!
StampeedValkrie has done an outstanding job of displaying the evolution of the PSE/Code 3/Force 4 SD series of lightbars. Parts do not interchange between the Federal Signal TwinSonic and PSE/Code 3 SD bars.
They look similar and you can, with some irreversible modification, get the domes to swap, but that's about all. There have been instances where someone would take a worn out TwinSonic and swap in Force 4 SD or XL independent rotator assemblies, which is a way to breathe new life into a dead TwinSonic.
I've never seen one in person but they appear to be more visibly effective than Twinsonics.There are 3 generations of SD bar,
SD overview..
Code 3 SD Bar Overview
Keeping the informational videos going on vintage lighting. This time I am talking about a Code 3 SD bar.. Basic how to information, and things worth no...
1st Generation..
Had unique lamp holders.. reminds me of the same type of holders found in some Grote beacons.
1st Gen minibar..
2nd Generation..
This is where the internals started being the same as the XL9K series bars. Some internals.. but not ALL could be swapped between the 2 series.
2nd Gen minibar..
3rd Generation..
This is where the sealed beam bars were phased out, rotators were now the same as found on the XL5K series bars.
Other the the same square or rectangular shape, nothing between the SD and the Twinsonic bars are the same. As to which one is better? Personal preference, they have grown on me I find them more interesting to tinker with then Twinsonic bars.
They can be. They do produce a semi-unsynchronized flash pattern as opposed to the TwinSonic's constant synchronized pattern. From the end of the bar, effectiveness is the same, but I do think the SD had an advantage when viewed from about a 45 degree angle. At that angle, the Twinsonic had one pair of rotating bulbs on each end providing excellent protection, but the mirrors were now at a steep angle to the viewer and no where near as effective. On the corner closest to the viewer, only the mirror panel closest to the speaker section would provide an effective reflected flash, the mirrors on the opposite side were completely blocked from view. The SD had two pairs of rotating bulbs on each end providing effective corner protection, plus the V-mirror's angle still provided one reflected flash from both sides of the bar.
From the rear, a model 12 Twinsonic had only two pairs of rotating bulbs visible, but the 12-X split the mirrors horizontally so as to provide better rear protection. Unfortunately, splitting the mirrors resulted in 1/2 height reflected flashes, reducing the flash effect. The SD had four pairs of rotating bulbs providing full power rearward flashes.
One downside to the SD bars were that they drew more amps than the TwinSonic. A TwinSonic with 60 watt 4464 bulbs has a constant draw of about 20 amps. The SD bars with 35 watt 7400 bulbs has a constant draw of about 24 amps. One might argue that that the lens fluting of the 7400 bulb made up for the difference in brightness between it and the 4464 bulb, but I swear you can feel the light impact on your skin when the beam from a 4464 bulb hits you.
Maxim2Eng
Supporting Donor
A peculiar phenomenon of the model 12 was (because of the counter rotating lamps),when viewed from a 45 degree angle, the lamps appeared to alternate (much like a model 11).
Quite true, that was due to the TwinSonic's driver's side and passenger side rotators revolving in opposite directions.
TDC
Lifetime VIP Donor
Looks like it says "Code 3 BAF Model: 2300" on the catalog scan. Actually says "synchronized" in there, too, which is kinda true, but only on one side.
The SD/XL doesn't seem as effective as there is little off time; a lot of background light bounce. Federal actually promoted that off-time saying you should buy a 17 instead of the 17x series, which always seemed kinda weird marketing.
Always seemed like the C3 bars were copies of FS, just a bit different to be different.
The SD/XL doesn't seem as effective as there is little off time; a lot of background light bounce. Federal actually promoted that off-time saying you should buy a 17 instead of the 17x series, which always seemed kinda weird marketing.
Always seemed like the C3 bars were copies of FS, just a bit different to be different.
How effective were the Twinsonics? I'm a bit younger and only recall strobes and LEDs, mostly Whelen tech (yeah CT). A lot of police agencies used Twinsonics in the 70s and 80s before transitioning to Whelen tech.
ex416
Member
there appeared to be a transitional phase in the Code 3 SDs between what stampeed referred to above as 1st generation and the 2nd generation where they started using the later style quick change clip style bulb holder assemblies with the 1st generation (pan style) frames before a complete switch over to the 2nd generation (tier style) frame that was also used in the 3rd generation. this may have possibilty been done to use up left over 1st generation frames.
10-99.NET
Member
FedSig never patented the TwinSonic. Gosswiller, the inventor, patented the theory of the enclosed bar in 1968, but his design and patent is exact to the Mars Spectra bar and the TwinSonic's mechanism is the same as the patented Visibar. Code 3 PSE patented the design of the SD in 1978. It's internals are far different than the TwinSonic.
Maxim2Eng
Supporting Donor
Actually, the mechanism of the model 12 (TS) is similar, but not the same as the mod 11 (often called the VisiBar because that was the name of the bar itself…it’s ”real” name was the Twin BeaconRay. The VisiBar—bar & mounting hardware—could be purchased separately). The mod 11 used a chain inside the bar to synchronize the two beacons (one with a motor, the other without). The Mod 12 used a gearbox with two drives connected to the bulb holders by chain that made the two sides counter-rotate (from above, pass side CW; driver side CCW). Thus the “patented Hand Clap” flash pattern.
The SD used a belt in each pod to sync the bulb holders. The two (or 3) pods were not synchronized.
The SD used a belt in each pod to sync the bulb holders. The two (or 3) pods were not synchronized.
I remember reading somewhere that he got the idea for the Twinsonic while looking at a Visibar, with the beacons reflecting off of the chrome speaker in the center.
10-99.NET
Member
No sir. The first patent is from Honeywell on their relay sequence and the second is for the VisiBar with Twins and speaker. Same concept and mechanism for the TwinSonic, but his enclosed concept patent (3,404,371) actually looks exactly like the Mars Spectra System enclosed bar ('67-68).
10-99.NET
Member
10-99.NET
Member
Just quoting what is on the Federal Signal tag affixed to the ends of my Model 12 TwinSonic.
Maxim2Eng
Supporting Donor
Interestingly, the Mars Sectra was similar in execution as the SD in that it’s was two independent pods mounted to a bar with a speaker enclosure in the center making it appear to be a single unit. The patent for the yet-to-be-named TwinSonic describes the features of a fully synchronized counter rotating lights with mirrors positioned to reflect the the light “generally forward”. It also included provision for a siren speaker to make it a completely enclosed system.
“52: The siren 54 does not constitute a part of the present invention and is shown merely to illustrate how such a component may if desired be mounted within the housing 22 together with the combination of rotating signal lights and mirrors which constitutes the present invention.”
BTW, my model 12 says the same thing, but it may be a gubmint fubar:
That is the patent for the Nightprobe Option!
This is the SD Patent -> https://patents.google.com/patent/US4004274A/en
It looks to me that the TwinSonic itself is not patented. But it is based on the 3 patents named on he nameplate.Interestingly, the Mars Sectra was similar in execution as the SD in that it’s was two independent pods mounted to a bar with a speaker enclosure in the center making it appear to be a single unit. The patent for the yet-to-be-named TwinSonic describes the features of a fully synchronized counter rotating lights with mirrors positioned to reflect the the light “generally forward”. It also included provision for a siren speaker to make it a completely enclosed system.
“52: The siren 54 does not constitute a part of the present invention and is shown merely to illustrate how such a component may if desired be mounted within the housing 22 together with the combination of rotating signal lights and mirrors which constitutes the present invention.”
BTW, my model 12 says the same thing, but it may be a gubmint fubar:
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