Film-Tech Forum ARCHIVE: Projectors RCA FR-35 DP and KN-15

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Posted by Thomas Jonsson (Member # 1902) on 01-22-2006, 06:38 AM:

Going through some 30 years old issues of Cinematographer I found
two different projectors I´ve never heard of. One is a (probably)
Russian 35/70mm machine "KN-15", and the other is an RCA FR-35 DP.

The RCA was probably some kind of studio machine, but since the
ad stated it was supposed to project onto big screens (lamps up
to 4500 watt xenon could be used) I´m curious if it was installed
in theaters as well.

Anyone who knows anything about the two?

Thomas

Posted by Gordon McLeod (Member # 33) on 01-22-2006, 08:26 AM:

I beleive the RCA was used for a lot of telecine apps
It was a electronic intermitent and to a large extent looked like a FP20 in many ways
I beleive it was based on the eprad patent using a feedback servo stepper system to drive each of the sprockets
It was also used as a rock and roll dubbing machine often paired with the RCA dubbers

Posted by Mark Gulbrandsen (Member # 72) on 01-22-2006, 11:27 AM:

I'm not so sure that the RCA was based on the EPRAD patent. RCA was a company that never but never paid royalties to any other company or individual... Philo Farnsworth was about the only exception to that which I am aware of and that was after a decades long lawsuit that ultimately destroyed Farnsworth and ruined his health.

After RCA was gobbled up by GE the RCA projector people later set up on the west coast and the resultant designs eventually became the Westrex Electronic Projector which was largely run by Charles Fox. Fox later sold Westrex to Christie where it became the Christie electronic projector. Charlie Fox is still around and so are his electronic projectors. His company is called Showperfect Charlies projectors also ran in many Showscan venues. For those that are interested in how they work there are also many schematics on their web site.

BTW: The first RCA FR35 was a big disaster and had tons of ptoblems but the later FR35B was quite good and extremely reliable. The B model could run at 24 or 30 fps and do either standard "theatrical" pull down or TV pull down just by changing a suitcase jumper on one of the boards. About the only bad thng that a B model could do was blow a servi rail fuse and send a full reel of film running at 30 rpm to an instant 30,000 rpm... ok, I', exagerating a bit but it went really really fast instantly! Always damaging what ever film was on the reel.

Posted by Richard Fowler (Member # 893) on 01-23-2006, 11:40 AM:

The RCA unit was a pain to service but gave me steady service calls and standbys long time ago [Smile]

The KN-17 is the Russian portable projector identical in construction to the East German TK-35 with slight exceptions in the take up assembly.....and of which has a better designed knockoff in the Phillips FP-3 portable.

Posted by Thomas Jonsson (Member # 1902) on 01-23-2006, 12:24 PM:

Thanks for the info about the RCA machine. It looked very
futuristic, a nice looking machine actually.

Richard. The Russian projector I mentioned was KN-15, not KN-17.
It´s a 35/70mm machine, and it looked anything but portable. Do
you know anything about it, or where to find some info?

Thomas

Posted by Alejandro Lopez (Member # 2854) on 01-23-2006, 12:31 PM:

Hi: Put the pics of the KN-15 and I´ll try on my archives and some European pages to find information for you. I´ll thank an scan of the articles too, both KN-15 and RCA projector (and pics too cause I´d like to see it). Best wishes.

Alejandro.

Posted by Richard Fowler (Member # 893) on 01-23-2006, 01:41 PM:

KN30K projectors which I assume are the most current 35/70mm projectors are distributed by Tento of Moscow....KN17 / 20 are portable 35mm. Some of the KN machines have been imported to France, Africa, India.

Posted by Paul Trimboli (Member # 1509) on 01-23-2006, 08:49 PM:

Does the KN 17 have a big wooden drive gear and wooden gate runners? There is a guy I know who has a pair of Russian made portable 35mm but he does not know what brand they are, but the fact the main drive gear is wood is a bit of a worry.... then again the Russians used treated oak for their re-entery heat sheild! [Smile]

Posted by Alejandro Lopez (Member # 2854) on 01-24-2006, 07:41 AM:

It´s not wood but Celotex or so. You´ll find many projectors with gears from that material.
Alejandro.

Posted by Richard Fowler (Member # 893) on 01-24-2006, 09:46 AM:

Phenolic - Celotex...no. The KN has a wood drive gear. There is a local Cuban technician who had to work on scores of the machine to rework the main drive gear due to swelling in the high humidity in the Caribbean.

Posted by Robert E. Allen (Member # 1351) on 01-24-2006, 12:52 PM:

The RCA machine I'm familiar with is a Brenkert with an RCA label on it. I ran a couple of them years ago in Southern California.

Posted by Mark Gulbrandsen (Member # 72) on 01-24-2006, 07:14 PM:

I agree with Richard. The grars on my pair of KN's are very definately made from wood. The grain is clearly visible too. The pressure skates are also made from what appeears to be the same exact wood.... Probably well aged Vodka crates.....

Mark

Posted by Paul Trimboli (Member # 1509) on 01-24-2006, 07:26 PM:

Are parts even still made for the TK-35s and the KN 17? I would assume there would be people in Germany still making parts as there seems to be alot of these machines running. Are they any good? They look nice and small and are very simple in their design.

Posted by Phil Hill (Member # 371) on 01-24-2006, 07:49 PM:

This is sooo exciting I can hardly contain myself....... [sleep]

Posted by Mark Gulbrandsen (Member # 72) on 01-24-2006, 09:03 PM:

Whats a matter Phil, Somethin bite ya in the ass? [Razz]

Posted by Marin Zorica (Member # 1716) on 08-08-2006, 08:55 AM:

I well know KN-15(17 - two projector version with changeover) and TK-35 projectors.

Recently i upgraded two KN-17 to red light so they can read cyn films, only problem is that i have to change slit lenses and photo diodes, because original was not so sensitive to red light spectrum. And slit lenses have no slit mask, slit image on film is actually image of exciter lamps filament (4V, 0,75A) this is very very bad thing about this machines.

TK-35 was made based on KN-17 but is much better machine, and also have very good sound head so is easy to convert to cyan and stereo, also TK-35 is less noisy than KN-17 which is important if You don't projecting from bot!

If somebody is interest I can upload some pic here?

Posted by Clive Carmock (Member # 2882) on 08-11-2006, 04:44 PM:

Marin - I have a TK35 which I have converted to stereo using a cell from a Westrex 7000. This works very well. I would like to change the light source to red LED or Laser. As you say there is no slit in this machine - but an arrangement of prisms and ground glass.

How did you install the red light srouce?

I find the Tk35 runs smoothly, and is very gentle on film. This model does have the wooden pressure runners and felt runners on the aperture plate, but the gear is metal.

Does anyone know if different ratio aperture plates are available for this model?

regards
Clive

Posted by Stephen Furley (Member # 1277) on 08-11-2006, 05:08 PM:

quote: Mark Gulbrandsen
I agree with Richard. The grars on my pair of KN's are very definately made from wood.

Large gears, in things like watermills, often had gears with teeth made of wood, inserted into the wheel, and which could be replaced when they wore, but how can you make an entire gearwheel out of wood? If you simply cut out a circle and machined the teeth on it then some of the teeth would have the grain running in the wrong direction, and would almost certainly break off. Was the wheel built up from small segments, with just a few teeth on each, so that the grain was almost radial on all teeth, or were the gears laminated, or what?

Posted by Marin Zorica (Member # 1716) on 08-12-2006, 04:37 AM:

quote: Clive Carmock
I would like to change the light source to red LED or Laser. As you say there is no slit in this machine - but an arrangement of prisms and ground glass.

NO, TK-35 have slit inside of sound optic, and You can see slit when you remove exciter lamp holder! Projector that doesn't have slit in optic is KN-17/15!!

For LED or Laser, just use similar with projectors which have same exciter lamp like in TK-35, but You can't use that laser that hold directly on sound optic, because You can't attach that to TK-35 optic, You must use something like JAXLight that hold on exciter lamp holder.

Posted by Christian Appelt (Member # 1067) on 08-15-2006, 11:25 AM:

Marin,
in fact the KN15/17 machines are based on Zeiss Jena's TK-35 which came out in 1947, just like that 35mm portable from India (forgot the name).

Paul,
TK-35s were in wide use for mobile theatres in East Germany until the Berlin wall came down in 1989. They still are popular among film collectors and people who like to tinker with lamp systems and sound readers...actually, the TK-35 is not a bad piece of machinery. Look here for some modifications (large reels, stereo sound, quartz lamps):

http://gallery.filmvorfuehrer.de/view_album.php?set_albumName=TK-35

and a restored pair with pics of the maltese cross movement:

http://gallery.filmvorfuehrer.de/view_album.php?set_albumName=Album-thomaskino-TK35

It is extremely small, but not very gentle on film (although not nearly as bad as some Italian portables). Spare parts are available because so many TK-35s were sold from military storage, so it is quite easy to get any part you need.

The problem with all TK35 clones is the path of light which makes it hard to get sufficient brightness on the screen. If you need any advice on TK35, post your question here:

www.filmvorfuehrer.de

and click on FORUM > ALLGEMEINES BOARD, then on button NEUES THEMA.

Posted by Clive Carmock (Member # 2882) on 08-15-2006, 04:07 PM:

Christian, do you know if anyone can supply alternative aperture plates for the TK 35? I only have a full frame one at present.

I hoped Wittner might have them, but it seems they don't. I see they now have a bracket to fit a stereo cell into the TK 35. Some time ago I used part of an old speaker bracket to make a mounting plate to achieve the same.

Do you know anyone that has tried the Wittner red LED exciter lamp replacement for this machine?

Regards
Clive

Posted by Marin Zorica (Member # 1716) on 08-15-2006, 04:54 PM:

Don't know about Wittner, but mine is working realy fine!

Stereo cell holders is best to do homebrew is YOu can supply You're self a stereo solar cell chip and is easy to do!

Posted by Christian Appelt (Member # 1067) on 08-21-2006, 07:53 AM:

Clive Carmock wrote

quote: Clive Carmock
Christian, do you know if anyone can supply alternative aperture plates for the TK 35? I only have a full frame one at present.

I will ask some TK35 owners I know whether they have aperture plates.
Did you just check Wittner's website or did you ask especially for aperture plates? They do have some spare parts in their catalogue, like the wooden pressure pads in the film gate, sprockets and lamp mirrors.

UPDATE:

Just spoke to a friend of mine who has several TK35 machines. He may have some spare aperture plates. Please check that you have the later model of TK35, the first series does not have interchangeable aperture plates because the original 1947 design did not call for wide screen formats.

I heard that even in the 1960/70s, many TK35s were sold with the fixed gate because the low light level did not encourage anamorphic wide screen projection.

[ 08-21-2006, 11:26 AM: Message edited by: Christian Appelt ]

Posted by Clive Carmock (Member # 2882) on 08-23-2006, 03:54 PM:

The TK35 I have has the removable aperture plate. I have the 1.33:1 plate at the moment and really would like to get the widescreen plate if one should be available.

Regards
Clive