Recent content by shues

The way I understand it, a doubling in loudness requires a 10 decibel increase. Adding a second speaker, thereby doubling the power from 100 watts to 200 watts, represents only a 3 decibel difference. Adding 3 speakers, for a total of 400 watts, would double the power twice, representing a 6...

You could be experiencing destructive interference if the speakers are wired out of phase relative to one another. To test this, disconnect one speaker's wires from the siren and reconnect its wires to the siren in the opposite way. Leave the other speaker's wires as they are.

That's a Federal model 17.

Here's one that's even older. Its copyright date is from 2010 and was last updated on March 4, 2015: https://www.whelen.com/wp-content/uploads/2020/08/14381.pdf

Check out that copyright date! ©2016 Whelen Engineering Company Inc.

The title of the thread, although it doesn't seem to appear when viewing the thread, says the application is a 2013 F150. I believe this application calls for a STPKT61L or STPKT61 depending on the length of the bar selected.

A few years back, I made what I believe to be a complete backup of John's entire photobucket. If you can provide a list of broken photobucket URLs, I'll see if I have what you're looking for.

The voltage at the diodes remains the same when in low-power mode as when in full-power mode. Pulse-width modulation (PWM) occurs at one rate for full-power mode and at a different rate for low-power mode. Whelen holds patent US6586890B2 that may be a good place to begin your research. If your...

Your best bet may be to use the outputs for the alleys or takedowns for the additional lightheads, then use the flashing alleys and takedowns function to flash those additional lightheads.

I think an RV-25 is the Unity beacon with two PAR36 lamps, while an RV-26 is the Unity beacon with two PAR46 lamps. I'm not sure, however, if this makes any difference to the part you're seeking.

No problem, I'll keep looking. Good luck selling!

By any chance, do you happen to have the LED lightheads that would serve as takedowns and/or alleys on these?

Installing a diode should almost certainly be sufficient to prevent that problem.

There is "Bill" on OfferUp in Oak Forest, IL who I suspect may be the same person.

If you look closely, you'll see that it's actually a Pierce Alert.