8mm Forum: Eumig S938 Lamp Voltage

»	8mm Forum » 8mm Forum » Eumig S938 Lamp Voltage

UBBFriend: Email this page to someone!

Author

Topic: Eumig S938 Lamp Voltage

Paul Adsett
Film God

Posts: 5003
From: USA
Registered: Jun 2003

posted September 10, 2019 11:17 PM

If you own a Eumig 938 or any of the 900 series projectors it is well worth checking the voltage at the lamp (with a good lamp plugged in and illuminated). I found that the lamp on my 938 was only getting 14.2 volts and the picture was unacceptably dim. So I changed the transformer tap from the normal USA 117 volts to the 110 volt tap on the transformer. This brought the voltage up to 15.1 volts which is where it should be, and boy what a difference in screen brightness - really impressive with an f1.0 lens! [Smile]

--------------------
The best of all worlds- 8mm, super 8mm, 9.5mm, and HD Digital Projection,
Elmo GS1200 f1.0 2-blade
Eumig S938 Stereo f1.0 Ektar
Panasonic PT-AE4000U digital pj

| IP: Logged

Mathew James
Jedi Master Film Handler

Posts: 740
From: Hamilton, Ontario, Canada
Registered: Dec 2014

posted September 11, 2019 07:00 AM

Good to know Paul! I'll have to test as well.

My understanding is that the median is 117v and thus why some things use it. The reason you may be getting more voltage at 110V can be due to the distance from the transformer on the pole.
You can read sometimes more than 120V if close and as low as 107 if some distance away.
It will be interesting to know. I am right in the heart of the City so i would be very close to a transformer i think....

--------------------
--
Cheers,
Matt 📽

| IP: Logged

Paul Adsett
Film God

Posts: 5003
From: USA
Registered: Jun 2003

posted September 11, 2019 09:38 AM

My measured line voltage today at the wall socket is 120 volts, so I don't think that is the issue for me. It must be that the transformer in my particular projector is putting out less voltage (14.2v) than the lamp requires (15.0v). This could be either due to manufacturing tolerances (seems excessive at -5.3%) or a deliberate under running of the lamp by Eumig to extend lamp life, or a combination of both. Personally I will take a much brighter picture at the expense of lamp life any day of the week. Would have been nice if Eumig had fitted a HIGH-LOW lamp switch on the 938 like they did on the 824.
I would be interested to know from Steve if he thinks setting my transformer connection at 110 volts (in order to get 15.0 volts on the lamp) will have any adverse effects on the amplifier electronics.

--------------------
The best of all worlds- 8mm, super 8mm, 9.5mm, and HD Digital Projection,
Elmo GS1200 f1.0 2-blade
Eumig S938 Stereo f1.0 Ektar
Panasonic PT-AE4000U digital pj

| IP: Logged

Leon Norris
Jedi Master Film Handler

Posts: 958
From: Elkins Park, PA, USA
Registered: Jun 2012

posted September 11, 2019 10:27 AM

Paul, what type of lens did this machine come with?

| IP: Logged

Paul Adsett
Film God

Posts: 5003
From: USA
Registered: Jun 2003

posted September 11, 2019 11:41 AM

Leon, the OEM lens is a Eumig f1.3 14-30mm zoom lens with the exclusive Eumig optical levelling feature, where the outermost objective lens slides along a rack and pinion track so that the image can be very easily levelled on the screen. It's actually a respectable performing lens although obviously not in the same class of the Elmo f1.0 zoom or the Kodak Ektar f1.0 22mm lens,

--------------------
The best of all worlds- 8mm, super 8mm, 9.5mm, and HD Digital Projection,
Elmo GS1200 f1.0 2-blade
Eumig S938 Stereo f1.0 Ektar
Panasonic PT-AE4000U digital pj

| IP: Logged

Steve Klare
Film Guy

Posts: 7016
From: Long Island, NY, USA
Registered: Jun 2003

posted September 11, 2019 12:00 PM

Hi Paul,

Am I the "Steve" you mean? (Such a common name I don't usually answer when somebody yells it out!)

I would imagine that Eumig would design some reasonable voltage overhead into their amplifiers. Moment to moment, and place to place the line voltage is changeable: 8PM in July with the whole neighborhood lit up and using AC, electric stoves, dishwashers and food processors to 3AM in October with nothing running but alarm clocks and some guy down the street sitting alone in the dark, pounding away on some film forum!

They can't afford to run too close to the top end.

(By the way, have you poked an outlet and measured what your line voltage is? It IS AC season...)

As far as the amplifier power, I think you will personally provide a correction. I would expect the volume at a given knob setting to go up as the voltage goes up, but I would also expect your ear-brain-hand system to turn it down just a smidge, even if you don't realize you are doing it!

--------------------
All I ask is a wide screen and a projector to light her by...

| IP: Logged

All times are Central

Printer-friendly view of this topic

UBB.classic^TM 6.3.1.2