Unitrol model 800 siren help

[denko3]

hey guys!
does anyone maybe have wiring list or instruction manual for unitrol 800 siren,anything?

thanks

 

[shues]

There is some information here:

https://www.thesirenboard.com/forums/viewtopic.php?t=3916

Another user asked about a model 800 and was able to use manuals from the x80 series sirens to get some transistor information, here:

https://elightbars.org/forums/threads/unitrol-800-siren-transistor-question.82450/

 

[denko3]

huh thanks shues helpfull but need some brushure or instruction manual or somethink like that....
very happy for info.anyway thanks! ;-)

 

[AlexM2013]

does anyone maybe have wiring list or instruction manual for unitrol 800 siren,anything?

I have some manuals for the UNITROL 800 and the 80 (This was the remote mount of the 800 and preceded the 80H and 80K re-design models) - what 'vintage' is it? From the late 60's to the early 90's they made quite a few changes to the design. The output transistors moved from Motorola Ge 2N1554 to the same Si devices used in the 80K (You need to mod the output circuit else there's insufficient bias to get the devices to turn-on with Mic and Radio re-broadcast). The Ge output transistor were graded by the supplier (I think Motorola also - we got some onetime in a TO-3 pack carrier that had Motorola labelling) and sent to Unitrol for assembly (the factory just used to match the HFE values of two devices at the factory) - that way they weren't stuck with a whole lot of brand-new but useless out of spec devices that even back in the early 90's used to cost over $5 a piece at distributor pricing.
Ed Nunn would never let on where he got some parts from and when spares were exhausted it made life challenging for an off-shore (10,000 Miles from the US) service centre and the customer wanting (demanding) a two-day turn around.

If you can post a photo of the siren oscillator PCB - I can probably find the right schematic for you? Any idea when the thing was made? There used to be a date stamp on the inside of the lid on some production runs

Alex.

 

[denko3]

I have some manuals for the UNITROL 800 and the 80 (This was the remote mount of the 800 and preceded the 80H and 80K re-design models) - what 'vintage' is it? From the late 60's to the early 90's they made quite a few changes to the design. The output transistors moved from Motorola Ge 2N1554 to the same Si devices used in the 80K (You need to mod the output circuit else there's insufficient bias to get the devices to turn-on with Mic and Radio re-broadcast). The Ge output transistor were graded by the supplier (I think Motorola also - we got some onetime in a TO-3 pack carrier that had Motorola labelling) and sent to Unitrol for assembly (the factory just used to match the HFE values of two devices at the factory) - that way they weren't stuck with a whole lot of brand-new but useless out of spec devices that even back in the early 90's used to cost over $5 a piece at distributor pricing.
Ed Nunn would never let on where he got some parts from and when spares were exhausted it made life challenging for an off-shore (10,000 Miles from the US) service centre and the customer wanting (demanding) a two-day turn around.

If you can post a photo of the siren oscillator PCB - I can probably find the right schematic for you? Any idea when the thing was made? There used to be a date stamp on the inside of the lid on some production runs

Alex.

Hey!
Thanks for so much help!
Look i will check the siren and let you now ok. ;-)

 

[Wailer]

From the late 60's to the early 90's they made quite a few changes to the design.

Did the sound of the wail and yelp tones change over the years too? I've heard only a couple demos of the Unitrol 800.

 

[AlexM2013]

Did the sound of the wail and yelp tones change over the years too? I've heard only a couple demos of the Unitrol 800.

In a word - Yes. The sound of the 800's and 80 siren changed a little from the early models to the last production in the mid 1980's - when we stopped seeing them for repair (around the early 1990's) (There were a few parts inside the sirens that changed also - sometimes undocumented changes from the factory that needed a fax to Dunbar-Nunn in Anaheim to find out if what we were repairing was legitimate - not somebody else's repairs.)

The earliest model 800 I ever saw was I recall made in 1973 with Motorola Ge output devices.
These had a lower wail tone pitch and the yelp was a little faster in rate than later models (The Hi-Lo sound didn't sound great). The early models were also designed for 8 and 16 ohm speakers. (At the time here in NZ, we used to use Japanese 'TOA' brand horn speakers on vehicles, so two 75W 16 ohm speakers wired in parallel worked great on the 8 ohm output setting of the 800's output transformer.)
The 800's I saw for repair that were made in the late 70's to early 80's and found there way down here to New Zealand had a slightly slower Yelp rate, than their predecessor, and the overall pitch of the siren was higher - not too dissimilar to the PA500M CHP2 from Federal.
The later 800's had an 'upgraded' output transformer that supported either a single 11 ohm 58W speaker or 11 ohm 100W speaker.
We came up with a local modification to allow the siren to run on 24V DC - Fire trucks here are 24V typically - something that you don't get in the US all that often.
(The mod was locally made output and driver transformers and new Si output transistors with changes to the amplifier circuit - none of which was sanctioned by the factory and caused confusion when some customers locally contacted Dunbar-Nunn directly to ask for repair information for their 24V Unitrol 800!! - We usually saw a 'snarky' fax from the factory asking us to take care of our 'local invention' please.)
(We also had to come up with a DC power filter circuit to stop 'Alternator Whine' getting into the siren - if the vehicle electrical system was a bit rough, because the 'upfitter' decided to move the Battery connection to another part of the vehicle - you often got 'Alternator Whine' coming through the wiring that upset the siren and usually caused the VHF Mobile Radio to do 'weird' things too.)

The thing is up until 1985 New Zealand had pretty hefty import duties on imported electronic sirens (there were two local company's making sirens: 'Elekon (Overseas) Ltd' and 'Electronic Alarm Industries Ltd' (both companies no longer exist in their original form), one model sounded a lot like a DIETZ Electronic Siren-Light) so couple the import duty of around 25% and sales tax of 20% on top of freight from the US and the base cost of the siren, any 'new' electronic siren that got to New Zealand was pretty darned expensive.
To get around the import duty, a local entrepreneur guy had the idea to import 'used' electronic sirens from the US around 1979-80 - these were exempt import duties, since they were 'used'. There was also some tax-lark going on because of the local labour to refurbish the 'used' sirens once they got here.
You guessed it, a truck-load of 'used' Unitrol 800's and 80's arrived around 1979 through to 1985-6 that had been removed from decommissioned/disposed of police and other emergency vehicles in California. The company I used to work for (no longer in business) used to repair these sirens.
I recall the owners of the company here having heated discussions with Ed Nunn (by fax and occasionally telephone) as to why so many 'used' sirens were arriving here and why we couldn't sell new products instead;

For the sake of completeness, by 1985 the import duty on foreign made goods was lifted and sales tax dropped, and Federal Signal won a huge deal with New Zealand Police for the Jetsonic Siren-Lightbar and similarly PSE's Code3 won a huge deal also with the Ministry of Transport (aka MOT) for the 3600/3672 siren and LP6000 Lightbar. (This was a time when the Police only did crime, and we had a separate Ministry of Transport that chased you for speeding and the like) the two forces were amalgamated into the NZ Police around 1987...

Probably the main reason the Unitrol product didn't get the same traction as maybe Federal and Code 3 was because Dunbar-Nunn didn't do lightbars. The emergency services here wanted a one-stop solution that was integrated and one place to go to get it repaired and one person to finger for warranty claims...

I really liked working on the 800's - the internals were well laid out, the Printed Circuit Board could be easily removed, the circuit board traces were large and easy to solder, and it was relatively easy to fault-find, repair and replace components. And get the thing running inside 30-40 mins, compared to say a Code3 3672 with thermal problems. The 800's were a reliable workhorse overall.