Film-Tech Forum ARCHIVE: Portacine 35x Porjector refurbish

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Posted by Tony Smith (Member # 7191) on 03-24-2015, 12:09 PM:

Hi Folks
A Friend asked me to look at a Portacine 35x 35 mm Projector and lamp psu, thats a IREM P1x30 (20 volts 30 amps) any help with tips on this kit please.

Tony Smith

Posted by Tony Smith (Member # 7191) on 03-28-2015, 05:24 PM:

Hi Folks
AS it seems that the Cinemeccanica Portacine 35x is not may be known to you folks, I will inform you asto the progress with the refurbishment.

A lot of the projector side of things is taken from Vitoria5, but the take up reel has it's own motor, on the back of the take up reel, it also has a rewind mode so the film can be rewound on the projector.

The biggest let down is that the audio side of the projector has been "Got At" what was a mono pick up cell system, with line output XLR plus built in audio monitor with LS, is now a twin Cell pick up, with a Velleman 2.5 watt anplifier kit as preamps and 2x phono output as what? line or LS feeds, not sure all other bits all removed.
The audio mods are all in a plastic box with floting ground, run from a plug top PSU, via a dc voltage regulator.
We intend to put the audio back to as it was.

Tony Smith

Posted by Fredrik Sandstrom (Member # 8171) on 03-29-2015, 06:04 AM:

I have a Portacine. I'm not sure why you would want to put back the original audio system as it is mono only and not particularly good quality. I have removed the built-in amplifier and installed Cinemeccanica's reverse scan kit, with which I'm very happy.

If the projector already has a stereo cell installed you also have the option to wire that straight to a Dolby processor and remove whatever preamps are in place.

Posted by Tony Smith (Member # 7191) on 03-29-2015, 07:29 AM:

Hi Fredrik
Thanks for your info, one of the reasons that we are wanting to return to single cell pick, is that the mod is a bit "Heath Robinson" as the twin cells are just held in with Blue Tac, we were thinking of reinstalling, a Victoria 5 pick up cell kit to make it look more professional, but I not aware that you could feed directly to a Dolby unit a cell output, thought it would be too low in level.
Thanks again will look into this.............

Posted by Dave Macaulay (Member # 813) on 03-29-2015, 07:56 AM:

Dolby - all brands, really - processors were designed to have inputs directly from a stereo "solar cell" pickup. More modern red (or the previous IR) LED reverse scan readers work on much less light to the sensor and require a preamp to bring signal level up to the old exciter lamp system's output.

Posted by Tony Smith (Member # 7191) on 03-29-2015, 08:25 AM:

Hi Dave
Thanks for your info, we are still in a steep learning curve on this optical film projection, must say its very interesting though.

Tony Smith

Posted by Leo Enticknap (Member # 534) on 03-29-2015, 02:18 PM:

I guess it depends on what you're going to use the projector for when you've finished restoring it.

If you want it for genuinely portable use (e.g. one-off shows in venues that have no permanently installed 35mm equipment, or maybe even no permanent a/v equipment at all), then mono with at least integrated preamp and possibly power amp at all might be the way to go. You won't have stereo, but as with the classroom 16mm machines "back in the day", all you'd need to do at the venue is to connect a single speaker on the end of a long wire.

But if you're going to use it in a home cinema or other venue - at least, most of the time - where the cell's output can be connected to an audio rack, then a stereo cell hooked up to a Dolby processor (used CP45s and 55s can be picked up for almost nothing on Ebay, the last time I looked), with no signal processing taking place in the projector, would seem to me to be the way to go. But if you did that, the projector wouldn't really be portable any more, because you could only use it (apart from showing silent films) at a venue which has a CP and power amp rack.

Posted by Dave Macaulay (Member # 813) on 03-29-2015, 06:22 PM:

Even with a stereo cell or reverse scan system setup compatible with a cinema processor for 5.1 sound, you could just add a powered mono speaker (with mic input) and a 2-1 cable for portable shows.
A white light exciter and solar cell system will have a lot of trouble playing recent cyan sound tracks, plus would need a load resistor built into the above 2-1 cable to get decent quality sound for even silver tracks. A reverse scan unit with preamp doesn't need the resistor, and the red LED ones will read any sound track reasonably well. Avoid any IR led reverse scan system.

Posted by Tony Smith (Member # 7191) on 03-30-2015, 06:04 AM:

Hi Folks
Thanks for your replies, the projector will be used in both situations, so will need to be kept as a sort of portable unit.
Thanks once again for your input will let you know what it ends up as...............

Tony Smith

Posted by Fredrik Sandstrom (Member # 8171) on 03-30-2015, 02:41 PM:

I don't find that the need for a cinema processor makes my setup less portable. The projector is heavy and a pain to carry around. Reels are big and cumbersome. Films are heavy. A Dolby processor is lightweight and the least of my worries.

Posted by Jonathan Wood (Member # 4614) on 03-30-2015, 04:11 PM:

Hi Tony

If you need a mono sound head assembly for your machine , I know someone who has one. I'm in oxfordshire so not far away. I tend to agree that red LED / stereo cell would be best though. I have a Vic 5 that has a dual basement led soundhead that can easily be hooked up to either a Dolby CP or at a pinch a normal PA system , which although lacking the E Q of the CP, can sound ok, especially when it's used 'on the road' . Where did your machine come from ?
Jon

Posted by Tony Smith (Member # 7191) on 03-31-2015, 08:42 AM:

Hi Folks
Thanks for your input. John not sure where the projector came from
we are working on it for a colleauge of mine. Also another colleauge of mine has a Victoria 5 mono sound head, he tells me, it came from the projector which was at Chipping Norton, they now have totally upgraded to Digital Cinema.

Posted by Jonathan Wood (Member # 4614) on 03-31-2015, 09:08 AM:

Hi Tony

I have the chipping norton machine at home ! I think we may have a mutual friend, Robin ?

Cheers

Jon

Posted by Tony Smith (Member # 7191) on 03-31-2015, 11:26 AM:

Hi Jon

Yes thats the one

Tony Smith

Posted by Tony Smith (Member # 7191) on 04-07-2015, 04:15 PM:

Hi Folks
Slowly working my way through the portacine 35x, one question which I may know the reason for but, when I took the Lamphouse off, the turbo fan which is the top unit, draws air via the rear panel groves, to cool the lamp, had in the fan about 6 or so small, almost like ceramic pellets,I first thought they were some form of brick chips, but I wonder if they are there to keep the turbo fan blades clean? Never encountered this before is this correct?