This is topic Excess hum from Kodak Pageant Speaker in forum 16mm Forum at 8mm Forum.
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Posted by Douglas Warren (Member # 1047) on September 13, 2015, 01:11 PM:
I recently picked up a Kodak 8K5 Pageant projector.Everything seems to work fine on it (I'm new to 16 mm)but there seems to be excessive hum from the speaker.While a film is running it really isn't noticeable,but is really evident while in stand-by mode.Any thoughts on this from the more experienced collectors?
Posted by Steve Klare (Member # 12) on September 13, 2015, 01:46 PM:
If this was a Super-8 machine part of the problem could be pickup on the magnetic sound head, what's nice here is there is none.
My best guess is the filter capacitors in your sound circuits are dried up and aren't smoothing the power supply ripple as much as they should. You can't really blame them: they are supposed to be replaced after about 10 years and you are a couple of decades over that. (They stay healthy longer of you use them regularly, less in dead storage.)
Posted by Douglas Warren (Member # 1047) on September 13, 2015, 05:49 PM:
Thank you for the reply,as I wondered if the problem might be clapped out capacitors.Considering how old (late 50's vintage) this projector is,it's not surprising. I guess I have a soft spot for these old Kodak projectors.
Posted by Steve Klare (Member # 12) on September 13, 2015, 07:55 PM:
I spend a lot of time looking over the fence into the world of 16mm (The issue is storage space more than anything else...)
The day I open up the gate and step inside, it will probably come in the form of a Pageant.
If nothing else it would take me back to those great days in high school when we saw a film instead of listening to the teacher up at the board. (It was always a Pageant...have to get one of those great steel carts too!).
The capacitors shouldn't be too hard to replace. Even if they turn out to be not THE problem, it's just one less thing!
Posted by Douglas Warren (Member # 1047) on September 13, 2015, 10:09 PM:
I remember those Kodak Pageants from school as well.In elementary school we had film day from grade 2nd through the 5th.One great thing about film day was that it was usually near the end of the day and once the reels stopped spinning,you got to go home shortly afterwards.This is my first foray into the 16 mm world,and one thing I'm realizing is how much more expensive it is that 8 / Super-8!
Posted by Steve Klare (Member # 12) on September 14, 2015, 08:15 AM:
Imagine a time when an essential skill of being a teacher was operating a movie projector!
I remember the AV room at high school: shelves and shelves of Pageants and reels.
I was already a film guy back in high school: it was Nirvana!
They had one token dual-8 machine (just in case, I guess). One of my teachers borrowed it once so I could show one of my own films in class.
Posted by Douglas Warren (Member # 1047) on September 14, 2015, 10:55 AM:
I think I'm going to stick with the Kodak Pageants for any 16 mm needs.The more I research them it seems they have a very good reputation overall.When I first got mine and turned it on,it took a few seconds to warm up before the reels started to spin!That reminded me of my parent's old tube TV sets when I was growing up.
Posted by Steve Klare (Member # 12) on September 14, 2015, 12:39 PM:
Any projector that exists by the ton already has a leg up: at least there will always be plenty of transplant donors! (until you run into that one part that's worn out on ALL of them...)
I see plenty of Eikis down at CineSea and to me that's a sexy looking machine!
-but I'd probably start with a Pageant.
My basic plan would be get one projector...just a coupl'a films and call it a day.
16mm is a concept my son and I tease my wife about: in the worst case going there could cost me a fur coat!
I bought a 35mm reel last year. Made sure she realized it was only décor before I opened the box. (You get to our age you should be careful of surprises like this!)
Posted by Douglas Warren (Member # 1047) on September 14, 2015, 06:46 PM:
Eikis are nice machines from what I understand.I can only imagine how huge that 35 mm reel must be!When I placed a 400' 8 mm reel on top of a 1600' 16 mm reel,it looked like a 50' reel. So far (in 16 mm) I've picked up a few trailers & some TV programs.Looks like 16 mm films suffer from fading as bad as their 8 mm little brothers.
Posted by Barry Fritz (Member # 1865) on September 14, 2015, 11:03 PM:
I agree with Steve that is likely the filter caps. There may be a couple of them and they will likely be 3 stage caps. You will not likely find replacements. You will have to by separate electrolytic caps for each value and stuff them in the original cap shell or fit them underneath. It could become challenging as I believe there is a circuit board underneath and room may be limited.
Posted by Steve Klare (Member # 12) on September 15, 2015, 09:15 AM:
Barry, is a three stage cap three independent caps in the same package?
One factor you have in your favor here is in the 60 odd years since this machine has been built, the size of electrolytic caps has gone way down.
Unfortunately if it is the capacitors drying up, your choices are pretty much bite the bullet and do the fix or learn to tolerate the hum.
Within certain sane limits, you almost have to live with it: you listen to a modern piece of audio equipment, it's pretty hard to hear any hum at all at any reasonable volume levels. Then you take that expectation and apply it to something that was built before the Berlin Wall went up...
(It's amazing how much human factors including psychological ones play into something like audio reproduction, which should be measurably "good" or "bad"!)
I've done a lot of anti-hum work on my film audio system: I got it down to inaudible at normal levels, but even then you don't have to crank it very high to bring the hum out.
Posted by Douglas Warren (Member # 1047) on September 15, 2015, 11:31 AM:
Steve and Barry,
Thank you for the additional feedback and info.The hum reminds me somewhat of guitar amps I've owned in the past (tube models.) I ran several reels through the Kodak last night and "The Beast" performed well overall.
[ September 15, 2015, 01:43 PM: Message edited by: Douglas Warren ]
Posted by Steve Klare (Member # 12) on September 15, 2015, 12:46 PM:
It's possible this may be as good as it can be!
Have you driven a really old car recently? They are fun, but the brakes are just soooooo leisurely compared to newer cars. I changed mine over to power front disk because when I was driving in traffic with other cars that are 40 years newer and we were all stopping they did it with so much less pedal pressure (and anxiety!) than I did....
My Dad on the other hand towed a trailer with brakes like these!
-and why not: all the cars on the road with him took just as long to stop as his, so they weren't all of a sudden squatting in the road ahead waiting for him to clobber them!
This could be the same thing: maybe it's just as good as you should hope, even without the capacitors being a big issue.
-It's just old!
Posted by Douglas Warren (Member # 1047) on September 15, 2015, 01:48 PM:
Good point Steve and I love the analogy with old cars.Since I've returned to the hobby after a 25 year absence,not only I have gotten older,the machines have too! I now realize with every projector I purchase (and considering how old these things are now) they're going to need a certain level of work just to keep them running. Overall I don't mind this as I enjoying tinkering with stuff.I just consider it another facet of the hobby to enjoy.
Posted by Barry Fritz (Member # 1865) on September 15, 2015, 02:51 PM:
Steve, yes, two, three and sometimes four stages in a single "can". They will be on top of the amp chassis and can be all silver, or may have a paper label, or may have a black cardboard covering. You cut them off, heat up the can and remove the contents so you can slip the can over your new caps. On what is left on the chassis, you dig the contents out and then drill small holes for each new eletrolytic wire and the ground to go through. From the underside, you need to solder wires to correct terminal. Radial caps work best.
Posted by Steve Klare (Member # 12) on September 15, 2015, 03:19 PM:
I'll see your 20uF and raise you 2uF!
22uF, 450V Electrolytic Cap
(20uF is not a standard value and available only in obscene minimum buys!)
This cap is .63" diameter, how big is the existing can?
Is there any reason someone couldn't replace the individual caps one at a time on the circuit board and then unify them either with a tyrap or some adhesive without using the original can?
(Don't mind me...I just like to fix stuff, especially if I don't need to do the real work!)
Posted by Barry Fritz (Member # 1865) on September 15, 2015, 04:05 PM:
Steve, there is no reason why it cannot be done as you describe. I have done it both ways. It depends mostly on the size of the replacement caps and the amount of space under the chassis. I have also done one with two stuffed in the can and the other two underneath. Old radio hobbiests like to maintain authentic appearances so they like the can replaced even if it has been gutted.
[ September 15, 2015, 07:06 PM: Message edited by: Barry Fritz ]
Posted by Steve Klare (Member # 12) on September 15, 2015, 05:26 PM:
Posted by Steve Klare (Member # 12) on September 16, 2015, 08:42 AM:
I got a dose of my own medicine last night:
I took down my Elmo ST-1200 and did a pretty thorough inspection and cleaning of the film path. Then after I finished I plugged it in to power and ran the transport just to make sure I got it back together right before I committed to running a film. (I'll still run a sacrificial print first...)
The hum was spectacular!
Was it really?
The difference is I didn't have it plugged into my sound system and I was hearing it raw through the internal speaker.
Probably if I operated this way for a week I wouldn't think it was all that bad. (I did for years, actually.)
Posted by Gary Crawford (Member # 67) on September 17, 2015, 06:46 AM:
The line output (monitor) from those machines(the st hd's) is usually a lot cleaner than from the power amp. That seems to add a lot of noise of all kinds....not as bad as some of the Eumigs, like the 700 series and even into the 800's somewhat. But the St has an excuse, partly. You've got two heads , two tracks and channels feeding into it sometimes.
I also tend to have a lot of noise coming out of me and I have have only a one track mind.
Posted by Steve Klare (Member # 12) on September 17, 2015, 07:58 AM:
I hadn't considered that. Actually the first time I ever listened to the ST Aux., I was already messing around with it hum-filter wise. I might not actually know what it really sounds like! One thing I'm completely sure of is you can get a wicked ground loop if you treat it wrong.
-but between the two of us we are taking an entire Forum Off-Format! (Yes: I started it!)
I'm really looking forward to CineSea, Gary, yet for no special reason: I just generally enjoy going!
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