DVD Recorders in the A/V room

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skiptaylor
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#21

Post by skiptaylor »

As to indexing talks, I'll leave that to the librarian and a card catalog. I'm long out of library class. ;)

The Casio disc printers look like a good line. Now to find someone to get them from (maybe direct?)

I managed to get to Walmart yesterday and found another DVR/DVD Recorder combo, a Philips DVDR3575H). They had it for around $297 or so. The clerk said there was a new batch of DVD players and recorders coming in about two weeks so I may go back then.

I think somewhere between now and purchasing the unit I settle on, I need to find out what outputs are available on our equipment to see what I need. Our satellite receiver (DVR396?) is so old that it's not even on the Wegener site, nor the manual in their archives. Right now I'm thinking the best way for input may be via RF as we broadcast English on channel 3 and Spanish on channel 6. It might save having the system rewired to suit.

Does anyone have an idea of what the Church has planned for the future in this area? By that I mean, if we spend a goodly sum of money on a DVR/DVD Recorder what would be the estimated useful life before Church technology obsoletes it?

Thanks for all the comments on this! I'm learning. :D

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rmrichesjr
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#22

Post by rmrichesjr »

In my previous stake, I had the user's manual for the DVR39* receivers, but I did not take a copy with me. If you really want the manual, I could see if I could find out who's doing satellite there now and see if they would send you a copy.

If I remember correctly, the only useful video output from the DVR39* was a baseband composite video. That was usually fed to a tree of between one and three video distribution amplifiers to feed the modulators, projector jacks, etc. If there's an extra output on one of your video DAs, you could get video from there. In theory, you'll get better quality from baseband video and audio than from RF. In practice, the difference in quality will be very small, especially if you have the black 1U rackmount modulators.

I have been told my current stake center has a Church-supplied DVD burner of some kind, but I haven't seen it or been told any details. (I'm in another meetinghouse, and we just got a new Church-supplied VCR in the satellite rack.)
skiptaylor
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#23

Post by skiptaylor »

rmrichesjr wrote:In my previous stake, I had the user's manual for the DVR39* receivers, but I did not take a copy with me. If you really want the manual, I could see if I could find out who's doing satellite there now and see if they would send you a copy.

Thanks for the offer, but it's not necessary!
If I remember correctly, the only useful video output from the DVR39* was a baseband composite video. That was usually fed to a tree of between one and three video distribution amplifiers to feed the modulators, projector jacks, etc. If there's an extra output on one of your video DAs, you could get video from there. In theory, you'll get better quality from baseband video and audio than from RF. In practice, the difference in quality will be very small, especially if you have the black 1U rack-mount modulators.

We do have the black rack-mount modulators. We also have a VERY long run to the satellite so the picture is ALWAYS a bit grainy due to low level. Not sure why they left it like that. I was told it was the best they could do with the long run.

Another reason I thought of RF was we broadcast English on Ch 3 and Spanish on Ch 6 so it would make it easy to record each broadcast unattended.
I have been told my current stake center has a Church-supplied DVD burner of some kind, but I haven't seen it or been told any details. (I'm in another meetinghouse, and we just got a new Church-supplied VCR in the satellite rack.)
I was told that there would be a DVD Recorder available via FM Group soon but that it would NOT include a hard disk drive. I'm really waiting to see what they approve to see what SL feels we need at the Stake then I intend to attempt to find a DVR/DVD Recorder combo to match if I can. The problem is the choices seem pretty limited in what I've been able to see on the net and the local Walmart.
russellhltn
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#24

Post by russellhltn »

Speaking of 1U black modulators, I've seen two different brands used. On the last renovation, they installed something like a "Pico" brand. Of the 6 we had, all but one died with a bad hum in the audio. They've since been replaced with (I think) Blonder-Tongue. If I'm not mistaken, Blonder-Tongue is one of the "big boys" in the CATV business so hopefully they will hold up.
skiptaylor
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#25

Post by skiptaylor »

RussellHltn wrote:Speaking of 1U black modulators, I've seen two different brands used. On the last renovation, they installed something like a "Pico" brand. Of the 6 we had, all but one died with a bad hum in the audio. They've since been replaced with (I think) Blonder-Tongue. If I'm not mistaken, Blonder-Tongue is one of the "big boys" in the CATV business so hopefully they will hold up.
Interesting you should say this. In recording yesterday's broadcast, I found channel 6 (the Pico) modulator with really bad video hum bars and an atrocious audio hum. I'll be on the phone with the FMG tomorrow about it.

Blonder-Tongue has been around a LONG time in electronics so they probably have a bit of a head start on later companies.
russellhltn
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#26

Post by russellhltn »

I haven't done it yet, but I think the Picos can be cheaply repaired. The power supply is dirt simple. As long as the power transformer hasn't burned out, all the parts in the power supply can be replace for about $7 at the local electronics store.
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thedqs
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#27

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The hum should away after adding a capacitor between the + to GND and - to GND.
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#28

Post by russellhltn »

thedqs wrote:The hum should away after adding a capacitor between the + to GND and - to GND.
Wellllllll, personally I'd like to find out what failed and get the circuit to work as designed (but with better parts so it doesn't fail again.) From a quick look, it appears the power supply uses a center-tapped transformer, two diodes, a cap and a basic 3 lead voltage regulator. A failure of any of those component will result in excessive hum. Shouldn't be hard to troubleshoot and fix.
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thedqs
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#29

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RussellHltn wrote:A center-tapped transformer
Failure in this wouldn't cause a hum just a complete failure. So most likely not.
RussellHltn wrote: two diodes
This would cause a reverse current and most likely destroy the board not cause a hum.

RussellHltn wrote:a cap
This would cause a hum from the DC voltage dropping to 0 every 60 Hz. Most likely the problem.
RussellHltn wrote:a basic 3 lead voltage regulator
Don't see how this would cause a hum, but if it was supplying too much voltage that might burn out the board and too little voltage would cause distortion not a hum.
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rmrichesjr
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#30

Post by rmrichesjr »

thedqs wrote:Failure in this wouldn't cause a hum just a complete failure. So most likely not.


This would cause a reverse current and most likely destroy the board not cause a hum.



This would cause a hum from the DC voltage dropping to 0 every 60 Hz. Most likely the problem.


Don't see how this would cause a hum, but if it was supplying too much voltage that might burn out the board and too little voltage would cause distortion not a hum.
An open in one leg of the transformer's secondary winding or an open in one of the two diodes might cause hum by increasing the ripple voltage, but only if the design had _VERY_ little voltage drop across the regulator or a rather large intended ripple voltage across the capacitor. Another possible cause of the hum might be some other component (maybe not in the power supply section) pulling excessive current, but that would be accompanied by said component getting unusually hot, perhaps glowing red or letting out some quantity of smoke. A short across part of the transformer secondary might reduce voltage enough to cause hum, but the transformer would get much warmer than usual. Looking at the voltage across the capacitor should go a long way toward revealing the true culprit. Better yet, if you have two units of the same brand, would be to compare voltages and waveforms between the two units.
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