Supercircuits MDVR-10 Digital Video Recorder for Occultations
Here's an alternative device for recording occultations that is small, portable, battery powered, records video and audio directly in digital format onto a compact flash (CF) memory card, plays back frame by frame, has a 2.5" LCD screen, and has a built in speaker.
This digital video recorder from Supercircuits, MDVR-10, is $259.99 (plus tax in Texas) + shipping. Its shown on Supercircuits catalog #61, page 52.
NOTE: THIS DVR IS NO LONGER SOLD BY SUPERCIRCUITS. USED ONES MAY BE AVAILABLE ON THE INTERNET.
My initial observations is that this unit performs identically to an 8mm camcorder. It has 30 fps recording capability, frame by frame playback, the LCD screen shows the star field exactly as that of my 8 year old 8mm camcorder screen (and tape). The screen is adequate to use to star hop to the target star and to watch the occultation event. Its battery powered (12V DC), small, lightweight and records video/audio onto a compact flash card. The built in speaker allows you to hear WWV as the occultation event(s) occur. The A/V inputs allow direct feed of WWV into the unit without the need for any type of microphone. I plug the audio input into the earphone jack of my shortwave radio. It records the time/date/position stamp from my McAfee GPS time inserter without any visible problems.
Here are the basic features:
1. Size: 3.5" x 5.5" x 1.3", Weight: 264 grams without 4 "AA" batteries. (454 grams = 1 pound)
2. 2.5" LCD screen
3. Compact flash (CF) cards for recording. The unit has no internal hard drive or memory. NOTE: I TRIED MANY BRANDS OF COMPACT FLASH CARDS AND COULD ONLY GET THE KODAK CF CARDS TO WORK. Strange but true !!
4. Has normal playback and fast forward/reverse ( 1x, 2x, 4x, 8x, 16x, 32x)
5. Playback can be paused on a single frame, or frame by frame playback (frame by frame playback is forward only, backward is 0.7 second steps).
6. Has a built in speaker with volume control.
7. It has A/V in/out. Comes with 2 RCA jack compatible cables. So you can record in and play out to a larger screen simultaneously. For a larger screen to watch occultation events, I place a 7" personal DVD player in series with the Supercircuits DVR. No loss of signal strength is noticed.
The MDVR-10 (right) allows output to another monitor, in this case a 7" portable DVD player (left) while the units records
8. There are separate recording inputs/output for video and audio, so no microphone is needed for WWV. As far as I can tell, the video quality is probably 95% the quality of 8mm recordings, which means I can barely tell.
9. Its recording format (codec) file on the memory card is MPEG4- SP ASF.
The audio codec is G.726/ 32 kbps
10. NTSC or PAL recording formats.
11. It records in 11-12 second size files (approx 1.2 Meg each) but plays back without stopping between files, including frame by frame. When copying the files to a computer, you’ll need to convert them to a usable format such as mpeg or avi, etc. Just about any conversion program can do this. Windows media player plays the files, but you really don't need any computer. It has a frame by frame playback !!
Recording frame rates: NTSC: 30fps @ 352 x 240 or 12 fps @ 704 x 240, NOTE: I CANNOT GET MY UNIT TO RECORD MORE THAN 27 FRAMES/SEC
PAL: 25 fps @ 352 x 280 or 12 fps @ 704 x 280
12. If you copy the files to a computer, you’ll need another program to merge the files together. An old program I have is Dazzle software that came with a video capture device. Several other programs are available to do this. Another one is Convert Movie.
13. Frame by Frame playback software is available for free on the web. And just about any ASF to MPEG or ASF to AVI file conversion software has a frame by frame player along with it.
14. I have found that upon close examination of the captured video, every now and then a frame gets lost in the recording on to the memory card. This might be due to the compression algorithm used. This is not a big deal.
15. Power source 12V DC or 4 AA batteries
16. Playback time on 4 AA batteries – 1 hour
17. Record time on 4 AA batteries – 35 minutes.
18. Recording options – high, medium or low quality. Hint: Always use high quality.
According to manufacturer specs: 128 MB Compact Flash card gives the following recording times:
High Quality: 20 minutes
Medium Quality: 40 minutes
Low Quality: 60 minutes
19. The unit has an antenna to receive 2.4 Ghz wireless video. But the wireless monitoring/recording is power hungry.
20. Power supply: 12V DC 1A, 4 "AA" batteries. Power consumption: 5.94W/495 mA.
21. Wireless video: The unit receives on up to 4 different channels (RF1, RF2, RF3, RF4) wireless video/audio at 2.4 Mhz.
22. It also has a programmable motion detection record start feature, this I suppose was intended for sleeping babies or recording intruders on property.
23. The unit has a Date/time overlay that increments in seconds. this can be turned on/off for recording.
Overall this is a useful unit for occultations. A typical occultation event is 5 minutes which would use 32 MB space on the CF card, so a 256 MB card could hold 7-8 events before you have to copy the data to your computer (high quality recording). The unit's LCD screen does not allow for any kind of brightness/contrast adjustment but I have found it to be satisfactory for watching occultation events as they are recorded. It took me less than 1 hour to learn how to use the unit and all of its functions.
Since the unit record in 11 second files, its a simple matter to edit out the events for later use in demonstrations or uploading to a web page. And the files can be merged by most any video playback program which there many on the internet.
It’s a cool device and I think I’m going to keep it. I was looking at the prospect of spending $75 for another camcorder battery or buying this unit.
This is my initial observations. Its useful because of the digital recording, frame by frame playback and built in speaker for hearing WWV. It can record off any TV, VCR, Cable box or any source with RCA jacks
Richard Nugent
IOTA Executive Secretary
Email: RNugent 'at' wt.net
Originally Posted 2006, revised September 2010.