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paulz
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# Posted: 15 Apr 2020 11:08am - Edited by: paulz
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Progress! I put up a white tarp between two trees yesterday, set the projector up on a wheelbarrow and waited for dark. Really happy with the brightness. I forgot what all the buttons do and was fumbling around in the dark but so far so good. Even managed to play a Dvd off my laptop.
This pic is at about 18" wide. Today the plan is construct a bigger better screen and run another test tonight after reading the manual again.
I bought an FM transmitter for sound but it's coming from China and will likely take a couple weeks to get here.
Last night I ran it off a generator. I would prefer to use my modified sine inverter but after hearing they can be bad for electronics I'm hesitant to.
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jhp
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# Posted: 15 Apr 2020 11:27am
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Looks great!
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justincasei812
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# Posted: 15 Apr 2020 01:29pm - Edited by: justincasei812
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 Awesome
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paulz
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# Posted: 15 Apr 2020 03:43pm
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Thanks! Ready for tonights test. Full 20x16.
Have to take a nap now. Doesn't get dark until after my bedtime. Might have to hire a kid if this pans out.
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paulz
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# Posted: 20 Apr 2020 11:30am - Edited by: paulz
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Houston, we have sound! Sort of. Found an AM transmitter for sale local, the FM transmitter I bought online is somewhere between China and here, probably closer to China since I haven't even received a tracking number.
So yesterday back in the ghetto I hooked it up in the dining room. You program a frequency that's not in use. Went out to the truck in the driveway, coming in crystal clear. Out in the street not so good, but the house and garage are in the way. Also I didn't check for a delay between the picture and sound.
Heading out to the cabin tomorrow to build the permanent screen. It will be on hinges and flops down onto the roof when not in use. At least that's my plan. Then I can test the whole ball of wax. I suppose an FM transmitter would be better, stereo?
If all goes well, might be popping corn this weekend!
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jhp
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# Posted: 20 Apr 2020 03:35pm
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Watt for watt, an AM signal should have less attenuation through obstacles than FM. I would guess it's very low power maybe - check the back of the unit, it might only be putting out 1/2 watt or something.
Either way it woudl work but yeah you'd get stereo using an FM transmitter.
I'd say try them both and send the one back if you don't need.
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paulz
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# Posted: 20 Apr 2020 05:48pm
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Looks like 100 megawatt? Is that good?
Here's the instructions
http://talkinghouse.com/pdfs/talking-house-i-am-radio-manual.pdf
I bought it off a guy on Craig's list, no going back. I'll find some use for it if it fails. The FM one from China probly won't go back either if it ever gets hereNo sweat, the projector was free... .
That one says:
Technical Specifications
Power supply voltage: DC 9-15V (12V recommended)
Operating current: Less than 2A
Frequency range: 76.0 ~ 108.0Mhz
Frequency step: 100kHz
Frequency stabilization method: PLL
Frequency stability: ± 10 ppm (-10 ° C to +60 ° C )
Frequency deviation: Less than ± 75kHz (100%)
Working method: Continuous
Clutter and Harmonic: Less than -60dB
SNR: More than 60dB
Stereo channels crosstalk: -50dB
Audio frequency response: 20 to 15000Hz
Audio distortion: Less than 2%
Modulation: 15%
Input level:-15dBV (adjustable)
RF output impedance: 50 Ohm
RF output power: 1W/7W (Power can be switched)
Reference range: 2 Km - 4Km ( in barrier-free environment with GP antenna)
Size: 160mm(L) * 95mm(W) * 54mm(H)
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ICC
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# Posted: 20 Apr 2020 06:06pm - Edited by: ICC
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Quoting: paulz Looks like 100 megawatt
copied from manual...
• RF Output Power: 100 mW average.
That is milli-watts. Not a lot of power, but that is the transmitting power, not the amplification power. It does not take much power to cast the signal a short distance. The receiver then amplifies that and if the receiver amp has lots of watts the sound coming out of the speakers will be "normal".
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jhp
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# Posted: 20 Apr 2020 06:59pm
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It doesn't take much but at the same time, 1/10th of a watt isn't going to go far at all, and even less with whatever tiny antenna it came with.
CB radios are "supposed" to max out at 4 watts, and on AM on a good day with a tall whip you might get a few miles, but functionally they are line-of-sight. Cheap FRS walkie-talkies are also limited to 4 watts, and while they are on FM, again they don't have much distance but you can get through a couple of buildings.
This low power might work ok in the wide open but even a watt or two on FM with even a rubber duck antenna will work much better for the couple hundred feet at the drive in.
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paulz
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# Posted: 21 Apr 2020 04:21pm
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Site testing the am transmitter. Works but could be better. It doesn't seem to like running it off a nearby generator, poor reception. Much better of the inverter
It's 18vdc, running through a wall wort. Also as you can see above the canopy, there are telephone lines in the street. No high voltage, that's up the hill on the other side. Static and poor reception as I go that way.
The transmitter has a 10' small wire for an antenna. I have been stretching it out on the groind. There is also a coax jack, I could try a dipole or something?
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ICC
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# Posted: 21 Apr 2020 05:09pm
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The generator may be generating interference as well as power. 
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paulz
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# Posted: 21 Apr 2020 11:01pm
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More successful test this evening. With the generator in my shop, the transmitter 150' away near the gate, reception was very good in my truck back at the shop.
Tomorrow I'll frame up a screen, fire up the projector and see if there's any audio delay.
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paulz
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# Posted: 26 Apr 2020 03:33pm
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Had my first full length movie showing last night. Just had two local neighbors over, three cars, as I was figuring on some glitches. The projector worked perfectly, so did the audio. Only glitch was the laptop/cd player battery giving up. I had the generator powering the projector but kept the player and radio transmitter on battery to avoid static. Minor things I will figure out for next Saturday night. I had spent most of the day on the screen without much time for testing.
I abandoned the idea of a screen on the shop roof, too hard to see that high without ramps. Instead I put pulleys on two trees 30' up. I can adjust screen height as well as put it up and down easily. I'm pretty wind sheltered, had an afternoon breeze but calm by nihhtfall. The seam in my screen all but vanishes.
Sure is neat to have the old drive in feel, they seem as happy about that as whatever is playing. I took some night pics but didn't come out. Looking forward to a summer of weekend showings. Thanks to all who advised.
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FishHog
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# Posted: 26 Apr 2020 06:06pm
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Awesome. Waiting for my invite
Topgun would be my preference;)
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jhp
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# Posted: 30 Apr 2020 09:30am
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Awesome!
Glad it turned out for you, pretty cool and unique feature to your cabin.
I feel like some classic 80s horror flicks would look awesome at your theater, like Friday the 13th series.
Keep sending the pics and let us know what is showing.
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paulz
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# Posted: 30 Apr 2020 10:30am
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Thanks guys, and of course I'd love to have you come visit, although not a good time for travel obviously.
I T'ed up this weekends feature, The Man Who Never Was, WWII British espionage, for a test run yesterday, ready to go. Today I'm just cleaning up the yard to make getting around easier.
A couple friends have seen drive in movie resurrections a topic in the news lately. I'm ahead of the curve for once!
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paulz
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# Posted: 4 May 2020 04:59pm
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Featured a great movie last Saturday night, The Man Who Never Was. Based on the true story of Operation Mincemeat, where the Brits planted a dead body with documents in the sea to fool the Germans.
https://en.wikipedia.org/wiki/Operation_Mincemeat
Luckily the movie played without interruption. Not without some pre-movie stress however. I went down an hour early to raise the screen, gas up the generator, run the cord, charge the batteries (I run the projector on a generator, the dvd player and radio transmitter on separate car batteries, at least for now), drag the equipment out and run a final test. About then it started drizzle. Shit! I put a tarp over everything and by the time I started the movie it had quit. All's well that ends well.
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