Signal Stat Dual Comm Info

[Maxim2Eng]

About a year + ago, I snagged a Dual Comm from a towing company near where I live--it had clear domes and no holes in the speaker cover. The domes were not broken but badly fogged, so much so I didn't notice it was missing a rotator! Oh well, I got it for $25. Oh, and the remaining rotator was missing a motor and mounting bracket. Did I mention it had clear domes?








I started my hunt to find placement part and several eLbers offers--thanks!, but the photos didn't match what I had. Color me puzzled. I was able to secure a two-bulb rotator on eBay recently that matched my cans for a good price, and, although it had obviously been "whacked" by an obstacle, I was able to repair it to near perfect condition.


In my search, and in postings here on eLb, I began to notice there appeared to be differing styles of bulb cans used by Signal Stat over the years--btw, the Signal Stat 350 two beam beacon uses the same rotator as the Dual Comm, but the Gen 2 Dual Comm rotators were "counter rotational" (was Gen 1? Doubt it--see below.).


Generation 1: Solid can; motor mounted in top of can; one power wire to motor (grounded through mount).











Gen 2: Vent holes added; gears moved to base of shaft. Motor gears remain the same, but the motor gearbox output shaft is in a different position/configuration; two wires to motor--power/ground--facilitating counter rotation.


Gen1 on left; Gen 2 right:





Note additional ground brush on shaft.


Gen 3 seems to be supplied by the same manufacturer to Dietz, which had different gears (same gearbox output shaft configuration) and only two "chimney" vent holes in the upper can.





The Dietz bars were very similar, but the domes were sloped on both ends. My mini bar cut was down from a full sized "dumpster" save and the Jefferson Co. (KY) PD cruiser with full sized bar (JCPD also ran the EMS service at first with red/blue lenses on ambulances--they also made traffic stops...that didn't last long).








Gen 4 abandons the "can" and uses a bulb holder system comparable to the FedSig 17X beacons consisting of an upper and lower plate.


So, I need a motor and mount for a Gen 1 rotator. I can fabricate a mounting bracket an use a Gen 2 motor. I've been buying 350s searching for spare parts, and soon, I will have about 6 Dietz rotators available for purchase.


If anyone has a Gen 1/2 Signal Stat spare parts bucket in their workshop, I would like to hear from you.

 

[JennyCop]

Great info thanks! . Also loved that Jefferson county Ford LTD with the Federal Q siren. Very unique set up.

 

[stansdds]

That's good info on the Signal Stat Dual Comm series bars.  A couple have turned up with Signal Stat 370 style rotating lamp holder assemblies, I presumed these were probably used at the end of production, perhaps Signal Stat was using up its supply of the model 370 assemblies.

 

[MtnMan]

Very interesting! My Dual Comm came with two slightly different rotators, one with a stripped gear. In my effort to find a replacement, I've come across a few of these variations. I'll inventory and report what I've got.

On the bars with counter-rotation, what was the standard orientation? Converging to the front or rear?

 

[chief1562]

Mine wasn't can type rotors, mine were more like a code3 SD style rotors.

Don't have any pictures of it since the change over on the site to retrieve them with.

And since it was gutted and parts sold I got rid of the pictures.

 

[Maxim2Eng]

Very interesting! My Dual Comm came with two slightly different rotators, one with a stripped gear. In my effort to find a replacement, I've come across a few of these variations. I'll inventory and report what I've got.


On the bars with counter-rotation, what was the standard orientation? Converging to the front or rear?

Here's a link to a great video of Gen 2 rotators in action:


www.youtube.com/watch?v=WoYL8-Hv1zE

 

[chief1562]

Doesn't work try again please.

 

[Maxim2Eng]

 

[chief1562]

It took me awhile to go through the old vintage for sale archives but I found the thread on what my Dual comm had in it.

Check out the pictures here.

 

[Maxim2Eng]

It took me awhile to go through the old vintage for sale archives but I found the thread on what my Due comm had in it.


Check out the pictures here.

That's what I call Gen 4. Up until the JCPD started using Dietz, Louisville was Federal Signal country. In my volunteer days, I would have liked to try the Dual Comm, but with a steady red over the driver...hmmm.

 

[chief1562]

So how would you date with the first 4 numbers or the 83?

And when was Gen 4 used?

 

[Maxim2Eng]

UPDATE:


I have been trolling fleaBay for any Signal Stat parts/beacons to complete my project (the 2-beam beacon uses the same rotator). In the process, I have snagged a Gen 1 rotator--slightly damaged but easily repaired, an NOS 350 2-beam beacon (a keeper just cause!) and three 350s in various conditions. That's when I discovered the different generations of rotators: solid "case" not unlike a FedSig 17; vented case; and the last iteration that had no case at all.


My initial guess was correct in that between the Gen1 solid case where the gears were inside the can at the top of the shaft and the Gen2 where the gears were on the bottom of the shaft and external of the can, the is a Gen2a...same running gear as the Gen1 but in the vented Gen2 can.





Gen2b on left; Gen2a on right


Note extra ground brush on the shaft of the Gen2b


Oh! And the motors from Gen1/2a are NOT compatible with Gen2b motors, which are isolated from the can with rubber mounting grommets in order to provide the ability to reverse polarity to achieve "counter" rotation on left/right sides.


So...anyone taking on a Dual Comm project beware of the 4 (or more?) possible parts dilemma that may confront you! As I have now acquired all the Gen1 parts now to complete the project with several complete 350s to spare, I look forward to resuming its completion after harvest (we had rain Tuesday--it's the only reason I had time to write this!).