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Dual Purpose: Mallincam AND Wireless - HOW?

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#1 Bowmoreman

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Posted 26 December 2007 - 11:35 AM

Well, I got two fabulous gifts for Christmas!

WATEC 35 mini monitor, and
Wireless hookup (transmitter and receiver)

Now, I have only one remaining question about how to hook this all up...

The MCHP outputs Svideo *and* RCA composite video. The WATEC 35 takes BNC Video in (I can use a simple RCA to BNC adapter for that), and the wireless transmitter also takes RCA composite input.

How do I get the effective TWO RCA video outputs from the single RCA out on the MCHP??? I really don't want to have to get a complicated additional electronic device, since I want to mount my WATEC on both (switching in between), my Refractor (in observatory), and on dobsonian (outside).

How are others doing this???

Power is no problem, its the video OUT going to two things simultaneously that both require RCA that is my challenge.

Can you buy an S-video to RCA adapter cable (I wasn't aware you could?)...

Help please!

TIA

clear enough skies

#2 Douglas

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Posted 26 December 2007 - 12:51 PM

Hey Dave:

I am splitting the RCA jacks with a splitter from Radio Shack.

The wireless transmitter only accepted the RCA jack and I use the adapter for the BNC connection to the WATEC. I'm not sure how much of the signal is degraded with the splitter but I didn't notice any real difference.

I am also curious if there is an S Video to RCA adapter and if that would preserve the S Video signal.

All that being said, a friend of mine started using S-Video for captured images the other day and found S Video did a much better job on image capture. I don't have any complaints with the live images through the split RCA connection at all.

I believe Jack uses composite for viewing and S Video for image capture. I like using the wireless setup and have been using composite only.

- Doug

#3 Douglas

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Posted 26 December 2007 - 01:02 PM

Hey Dave, I'm glad you brought up this topic. I just found an S Video to RCA adapter, I'm going to try it out ... check this out http://www.svideo.com/svideorca.html

- Doug

#4 rshassell

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Posted 26 December 2007 - 01:03 PM

Congrats on the new toys. Radio Shack sells several passive s-video / composite adapters, so you could convert the s-video output of the MallinCam for use with either the composite monitor or wireless transmitter. Just search for 's-video adapter' or some such.

I'd be interested to hear a report on your new wireless video. What model is it?

#5 jayscheuerle

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Posted 26 December 2007 - 01:37 PM

You will lose the benefits of S-Video quality by converting it to composite. Its benefits stem from the signal being separated into different brightness and color components, thereby giving the brightness more bandwith on its own, versus sharing it with color information.

From Wikipedia:

Compositing chroma/luma leads to blurry and low-resolution (approximately 420×486 pixels edge-to-edge) due to C/Y crosstalk

S-Video leads to sharp images (approximately 700×486 pixels edge-to-edge when using a clean DVD source)

#6 Douglas

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Posted 26 December 2007 - 02:06 PM

I was worried about that. The link I mentioned above advertises an S Video to Composite cable that minimizes signal loss and claims to be more than just an adapter:

They claim it provides near S Video quality when connecting to composite using their video cables. They have a comparison page with illustrations of the difference between video formats and video inputs. They compare S Video to S Video versus S Video to Composite versus composite to composite, using their cables, which is more than just an adapter.

Here is the link:

http://www.svideo.co...idcompare1.html

Click on the images to enlarge them, the differences are only really visible with the enlarged image.

I haven't used it yet and can't vouch for the quality but the comparison images are pretty interesting.

- Doug

#7 Douglas

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Posted 26 December 2007 - 02:13 PM

Check this one out, it converts Composite video to S-video, decodes and amplifies it.

http://www.svideo.com/co11.html


I am thinking that if I connect this decoder and amplifier to the wireless receiver and then send the converted signal into my TV's S Cable input, I can get a wireless signal that is truly converted to S- Video ...

- Doug

#8 greg

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Posted 26 December 2007 - 02:28 PM

Hey Dave:

I am splitting the RCA jacks with a splitter from Radio Shack.

The wireless transmitter only accepted the RCA jack and I use the adapter for the BNC connection to the WATEC. I'm not sure how much of the signal is degraded with the splitter but I didn't notice any real difference.

I am also curious if there is an S Video to RCA adapter and if that would preserve the S Video signal.
- Doug


I also wanted to split the signal from the camera to two different RCA jacks so I could use two different monitors, but I was worried that splitting the signal may in some way damage the camera.
Does anyone know for sure that it is OK to split the signal from the camera???
I believe that if you convert from an RCA signal to S-video adapter you will still have the less quality RCA signal to the Monitor or wireless transmitter.

Greg

#9 jayscheuerle

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Posted 26 December 2007 - 03:22 PM

Data is only lost, never gained during a conversion and amplification is the analog equivalent of rezing something up.

You can only get the best image out of the Mallincam through the S-Video output to an S-Video input.

#10 Jack Huerkamp

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Posted 26 December 2007 - 04:00 PM

If I am correct and you split the video signal to two concurrent output devices, you may damage the camera. If each output device is 75 ohms, placing them in parallel (through the splitter) results in the camera seeing a 37.5 ohm load. The net resistance for parallel operation is the product over the sum or (75X75)/(75+75). Since the camera is seeing a lower resistance, it may over-drive the video circuits. I know this to be the case with stereo speakers. I once placed 4 ohm speakers in parallel with a net 2 ohm impedance being seen by the amplifier. One day the unit decided to smoke itself.

I will pass this by Rock.

Jack

#11 Douglas

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Posted 26 December 2007 - 04:42 PM

Wow, nobody has ever mentioned the potential damage resulting from splitting the signal. I have used the camera with the splitter without incident but I will most definitely stop until we hear back from Rock. I will run the composite to BNC to the WATEC and will use the S Video output with an adapter for the wireless transmitter until we hear back from Rock.

I would really like to figure out how I can use the S Video output with a wireless transmitter but it sounds like that may be pie in the sky. Oh well.

The increased resolution from S Video looks pretty desirable.

- Doug

#12 greg

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Posted 26 December 2007 - 04:47 PM

If I am correct and you split the video signal to two concurrent output devices, you may damage the camera. If each output device is 75 ohms, placing them in parallel (through the splitter) results in the camera seeing a 37.5 ohm load. The net resistance for parallel operation is the product over the sum or (75X75)/(75+75). Since the camera is seeing a lower resistance, it may over-drive the video circuits. I know this to be the case with stereo speakers. I once placed 4 ohm speakers in parallel with a net 2 ohm impedance being seen by the amplifier. One day the unit decided to smoke itself.

I will pass this by Rock.

Jack


This exactly what I was Worried about. I too Smoked a very expensive Yamaha Amp. Once because of running too many speakers on Zone 2. :band: :rockon:
Don't want to smoke anything these days, especially NOT my MallinCam.... :imawake:
I have been running the RCA to my small monitor at the focuser, the S-video from the camera to a powered video converter box that has multiple RCA and S-Video outputs for use with other monitors and computers. Also my wireless video transmitter has S-video in & out and RCA in & out, the receiver has one S-video out and one RCA out.
I have not yet compared the image with the wireless compared to just using a good quality S-video cable but if the image is the same on my 9"HighRes. CRT monitor, then wireless will be the way I go. Capturing images on my laptop may need to be hard wired with an S-video cable for the best captured image, not sure, I have a lot of testing to do...
Greg

#13 Jack Huerkamp

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Posted 26 December 2007 - 05:41 PM

Doug,

I have not found an S-video wireless transmitter yet. I have been using an S-video to composite video adapter and then connecting it to the VFM Store transmitter. I know that results in a loss in quality.

Jack

#14 ccs_hello

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Posted 26 December 2007 - 06:07 PM

If a video camera has two video output (e.g., S-video and composite), it means internally, it is designed to handle them separately. If not, or just one source in such format is needed, the optimal solution is to get a Video Distribution Amplifier (e.g., one "in" to two "out" D.A.)
If not using a video D.A., I worry less on impedance mismatch (signal level will drop and DC restoration difficulties) or will damage equipment, but more on interference in between these two devices (device-oriented-noise, cross-modulation, or ground loop) through the common point where signal mixed. It may or may not happen.

I personally do not like S-video (Y/C separated) to be re-mixed into composite signal (due to a high(er) quality design would not be that cheap) while video DA can be very cheap. It can isolate two different receiving devices (monitor, transmitter) from each other as well as make sure signal level is correct.

BTW, any detailed spec on RF transmitter/receiver.
I have a very inexpensive (FCC approved very low power / short distance) pair which is *ouchy* :(.
(Optimized for low manufacture cost and uses 2.4GHz ISM band/analog modulation method.)

Clear Skies!

ccs_hello

#15 greg

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Posted 26 December 2007 - 06:33 PM


I run a 12' S-Video cable from my MallinCam down a truss pole to my S-video wireless transmitter that I velcro to my mirror box just below my truss poles.
I got the S-video wireless transmitter and reciever from Fry's Electronics Store. The model is Pure/AV By Belkin. It was a close out and cost arround $150.00 But they had a newer model taking it's place...Mo money...
Heres a couple of pictures.
Greg

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#16 greg

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Posted 26 December 2007 - 06:47 PM

And on the left the transmitter with the S-video in and out at the top. And on the right the reciever with the S-video out on the top...
I have not used the wireless much because when I used it with my 50" DLP TV the image was not very good at all. At first I thought the bad Image was because of light pollution, but now I believe the poor Image was also because the larger screen is showing all the defects of blowing the image up.
Soon I will try the wireless again, but this time it will feed my 9" monitor inside my Scope trailer/Warm room... Pay no attention to the man behind the curtain... :imawake:

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#17 ccs_hello

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Posted 26 December 2007 - 08:43 PM

Greg,

Is yours this http://www.pcmag.com...,1911923,00.asp $500 MSRP one?

If that's the unit, I would guess one possible reason for image degradation is it's using MPEG-2 compression (high compression, low compression?). But again, I would also say transmmit the signal digitally @ 5 GHz can avoid most analog interference and with digital encryption to add privacy is nice.

Probably you can try sending a high-quliaty DVD player signal to see what's going on.

I think which wireless unit to consider might be an interesting subject...
But please make sure it adheres to local country's frequency allocation, transmit power, and license. In US, the legal regulation authority is FCC. Please do verify that the transmitter has a valid FCC ID.
For US, please check frequency allocation in
http://www.fcc.gov/o...abase/spectrum/

If not sure, please ask the vendor!
(FCC legal? license requirement? transmit power within the allowed level? and possible others?)


Thanks for sharing!

Clear Skies!

ccs_hello

#18 Jack Huerkamp

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Posted 26 December 2007 - 08:44 PM

ccs_hello,

Here is what Rock said in reply to my request for clarification on using video splitters:

"Jack,

You can "get away" by plugging in a few devices but it is not recommended. It puts a load that exceed the output terminal voltage on the output amp of the camera. It would be better to use a distribution box with multiple output with a 10db gain amplifier in order to remove the excessive load from the internal amp in the camera. It will also equalize the final load and make the image a lot clearer. If no amplifier is used, careful adjustment of Brightness and Contrast will have to be observed on each monitoring device.

Rock"

Regarding wireless TX/RX sets, I am using the units available from The VFM Store (www.vfmstore.com). They are based in Hong Kong, but provide great service. Using the cheapest shipping method, I and others have received their units in 4 working days via global post.

Jack

#19 Bowmoreman

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Posted 26 December 2007 - 09:12 PM

Jack, after stopping by RS today, that is exactly the setup I'm gonna use... Svideo out from the camera to the wireless, and the composite video out to the WATEC 35...

cloudy though...
stay tuned

#20 Douglas

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Posted 26 December 2007 - 09:15 PM

Jack: Thanks for the update from Rock.

Since there are two video outputs, I will stop using the splitter and use the S Video output with a RCA adapter for the wireless unit.

The funny thing is that I don't have any complaints with the images I get using the composite connection and I love using the wireless transmitter/receiver from the VFM store.

I know S-Video will have a higher resolution and if it's available wirelessly I would be interested to see what I've been missing.

S-Video sounds like the next level for me. I don't know how much lower my jaw can drop, its pretty stretched as it is since receiving my MallinCam. :jawdrop:

- Doug

#21 greg

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Posted 26 December 2007 - 09:52 PM

Greg,

Is yours this http://www.pcmag.com...,1911923,00.asp $500 MSRP one?

If that's the unit, I would guess one possible reason for image degradation is it's using MPEG-2 compression (high compression, low compression?). But again, I would also say transmmit the signal digitally @ 5 GHz can avoid most analog interference and with digital encryption to add privacy is nice.

Probably you can try sending a high-quliaty DVD player signal to see what's going on.

I think which wireless unit to consider might be an interesting subject...
But please make sure it adheres to local country's frequency allocation, transmit power, and license. In US, the legal regulation authority is FCC.
For US, please check frequency allocation in
http://www.fcc.gov/o...abase/spectrum/

If not sure, please ask the vendor!
(FCC legal? license requirement? transmit power within the allowed level? and possible others?)


Thanks for sharing!

Clear Skies!

ccs_hello


Yes ccs_hello,
I'm sure that's my wireless transmitter and reciever. When I bought it it was a display model and did not come with any Info or power cords. I kind of took a chance but Fry's said that I could return it for a full refund if it didn't work. I had no idea the list price was so high...and I didn't know at the time about it transmitting in MPEG-2.
In your opinion what would be the best format for an S-video wireless transmitter and the MallinCam Color HYPER Plus Camera when used with a HighRes Color Crt monitor?
Thanks for your input.
Greg

#22 ccs_hello

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Posted 26 December 2007 - 11:13 PM

Greg,

Transmitting digital data without un-correctable loss (defined as bit error rate) is to use digital modulation. I.e., Digital RF modem. That Belkin unit has that module inside. We can find that recent HDTV, DirectTV, DigitalCable, Sirius Radio, etc. are all using digital RF transmission scheme.

The issue is that (especially high quality) non-compressed video occupies quite a bit of bandwidth (e.g., such as the current analog video broadcasting which will sunset in '09) thus there is a drive to compress it down. These are lossy compression.
MPEG-2 has several "profiles". Higher bandwidth (low compression) ones would be nicer. (Current HDTV is using MPEG-2). Some HD TV stations compress the programming too much, which isn't so desirable from end user viewing experience point of view.

Hope this helps!

Clear Skies!

ccs_hello


#23 JAT Observatory

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Posted 26 December 2007 - 11:29 PM

If I am correct and you split the video signal to two concurrent output devices, you may damage the camera.



I have been running both my Mallincam and GStar-EX camera this way ever since I got them. The S-video side goes from the Mallincam to my Dazzle box and the composite video goes the Slingbox.

The GStar-Ex is just the opposite. The S-video goes to the Slingbox and the composite video goes to the Dazzle.

This setup allows me to easily switch cameras by switching the input the display software is using, or I can view the same camera (either one) on 2 different outputs.

#24 Bowmoreman

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Posted 27 December 2007 - 05:54 AM

Wow, this turned into a great thread! After stopping by the local RS, I found they have a $21.95 Svideo to RCA adapter (about 1.5" long - very tidy/small). So this will be my route. S-video to RCA adapter, then high quality RCA cable (left over from my Audio/Video rig) to the 1.2Ghz VFM store Wireless transmitter... same old RCA to the WATEC.

Would LOVE to connect em up, but my CSC says not anytime soon!

I bought a 3 Amp switching AC-DC power supply also whilst at RS, and wired/soldered up a power harness that will feed the Y-adapter, and thence to the the camera and the transmitter... nothing fancy, just some braided red/black wire, bananas, etc... but low footprint!

I'll mount the PS under my mount on the pier...

Pictures another time, since it isn't setup yet, and its raining, and I have to go on a 400 mile drive in a few hours and haven't packed yet..

Glad Rock weighed in on this, though! And thanks to Doug, Greg, Jack, CCS... as well.

Clear enough skies

#25 ccs_hello

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Posted 27 December 2007 - 07:52 AM

Caution

Before purchasing RF transmitting equpment (i.e., intentional radiator), please ask the return policy, if the product does not meet FCC Requirements, licensing the spectrum used is not possible, licensing cost financially not reasonable (e.g., greater than $10,000 USD), and/or causing interference with other devices.

P.S., in US, FCC put significant burdens on the manufacturers, importers (who may become the sole stuckee, if the manufacturer is outside the US), and the users not following FCC rules/regulations.
Nice (and reasonably easy) reading:
http://www.atlasce.c...tes/fcc_doc.htm

Clear Skies!

ccs_hello


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