Power adaptor for MCM stabilizer

The MCM stabilizer doesn't have a NTSC/PAL switch and there's no mention of PAL on the MCM website anywhere.

In my help file on this, I recommend users replace the Chinese-OEM battery ASAP.

I don't know the size of the adapter plug needed.

I have found over the years that devices like this which run off a either battery or AC power often perform better with the battery: the less random unshielded AC wall warts introduced in the video chain, the better. If the thing burned thru batteries every week, it would be worth going to AC power, but these little stabilizers usually run a full continuous year or two off a good 9v alkaline battery like DuraCell.

Adjusting the internal pot wouldn't fix the NTSC DVD problem you describe: that sounds like a possible defect caused by the corrosion leak damaging something on the main board. Unfortunately, these have probably been sitting in a warehouse for years causing the cheap batteries to leak (not many people looking for a "VHS filter" these days). According to the member who discovered the pot, adjusting it can boost the filter function to stop the "invisible" CGMS protection in some broadcasts and DVDs- but this is different from MV and normally doesn't cause visible symptoms (it just triggers the "cannot record this material" lockout on your recorder). Here again, if you need to guard against both MV and CGMS your TBC1000 is better equipped for continuous operation. The little MCM-type filters are meant for occasional use: they can work 24/7 for those on a tight budget but if you own a pricey TBC1000 it makes a better heavy-duty AC-powered filter.

I'll support what Citibear said.

I had one of those for "stabilizing" video off VHS tapes, and the thing could go for months and months without me even thinking about changing the battery.

I don't think it ever failed on me. If the battery ever did get replaced, it was just an attempt to avoid any problem that might come up. Not due to any signs it was starting to fail.

Besides, little gadgets like that (ones that operate off batteries) sometimes don't do very well with an AC adapter. Seems to put out some type of interference. Don't know if that'd affect the stabilizer the same way, but if you were pressed for time and were using the thing, discovering after the fact the adapter had wrecked the video wouldn't be very pleasant.

If Cyclone82 does want to go with an adapter, I'd test the thing several times before deciding the results are as good as when it's battery powered.

I thought Cyclone had a typo on the mW rating, But from what you guys are saying it sounds correct.
I calculated 1750 hours running at that current draw for the typical 9 volt battery milliamp hour rating.

It isn't a problem with gear thats designed to run on AC wall warts exclusively. In your first post you asked specifically about running one of these little battery operated CP filters with an AC adapter, and thats what I was answering. These little black boxes have been sold for the last 25 years, the design has stood the test of time and they all operate more or less the same with minor differences. Most of them have been powered exclusively by 9v battery with no option for AC. A small handful have an AC socket, but like a lot of the battery/AC gadgets that come out of China the "AC option" is a total crock that they don't seriously expect anyone to use. It's there solely as an additional "feature" they can check off on a spec list to differentiate themselves from the 200 other battery-only boxes.

These things were originally designed to run on a battery, and for years there was no AC option. Forget the AC: the board is not optimized for it, you'll get more internal heat running on AC, and there's potential for interference (since you'll have to scrounge some random adapter). I and others have posted to tell you we get a year or more off an alkaline battery, with lithium it would probably go two years. They draw very little power, and automatically power on and off when they sense the presence or absence of an active video signal. Video gear runs a cleaner signal thru battery power (when that option is available) while audio gear generally performs much better via AC even if it offers a battery option. If you find a suitable wall wart, and don't pick any interference, then sure go ahead and use it- but I wouldn't go out of my way to find an AC adapter.

If that is the case, that the power supply is just in parallel with the battery I would strongly advise against using the power supply with anything other than a rechargeable in place. The design tells me that whenever the power adapter is hooked up it supplies charging voltage to the battery. While this is OK for rechargeable batteries(although not the best for them) it could cause non rechargeable batteries to leak or explode
"Personally" I'd forgo the power supply and just purchase a long lasting lithium smoke alarm battery. My guess it it would last many many years and would be cleaner power than a simple wall wart power supply. It may also not be the best to run just a power supply without a battery installed, it's possible the designers were figuring the installed battery would help filter any power fluctuations or noise from a power supply. Without a battery the voltage may be a bit high or noisy causing other issues. Again I'd just purchase a high quality alkaline or better yet lithium and forget it

This, Cyclone82, was what I meant when I said the the AC option was "a crock the mfr never seriously expected someone to use." This type of AC implementation is a poorly designed and possibly dangerous kludge by a copy-cat garage factory that ripped off the clone of the borrowed engineering of a duplicate of another copy of the first such filter going back 25 years. The original they're all ripping off ran on battery-only, and they're all too lazy and unconcerned to add a proper AC passthru circuit. Put in a lithium battery, and you'll have lost interest in using the thing by the time the battery dies. Trust us, these little boxes use only a trickle of power: they're practically self-powered by the video signal.

hi folks...

wellllll, come on, now....

true, you don't go to radio shack and grab some cheapo wall wart that happens to say 9v on it...

you'll find that most of these ( especially the 9 volt jobs ) actually toss out anywhere between 12v and 15v... bad news for this kind of design...

so step one is to either bring a voltmeter with you or make mr radio shack test it before leaving the store... the test should include an AC voltage test to ensure that the supply is, indeed, filtered... an unfiltered or poorly filtered wall wart will indicate at least a small amount of AC ripple...

beyond this, one can insert a small diode in series with the red lead of the battery connector to avoid pushing current into the battery, if it is connected at the same time as the power supply... ( i'm assuming that our friend is tinkerer enough since he opened up the case to have a look-see )...

in addition, adding an electrolytic cap to place into the battery compartment of the device will yield sufficient added filtering if needed...

also, these little gadgets PROBABLY are internally regulated down to +5vdc operating voltage if their inputs are specified at 9 volts... my GoDVD job wants a 7.5vdc external supply. it has no battery option, but i would think that these things are all probably running at +5 internally....

for those experiencing ' hot ' over time, you'll probably find that the ' hot ' is being generated by the +5 volt regulator that most likely does not have a dropping resistor in series with its input... this forces the regulator itself to dissipate quite a bit of power ( read - heat ) on its own....

typical 5v regulators need somewhere between 2 and 2.5 volts dropped across them in order to produce regulated +5, so our friend might even get away with a +7.5 vdc wart to reduce heat without sacrificing regulation...

indeed, the choice might be better since that 7.5vdc wart will probably put out more like 9 or 10 volts under no load conditions...

if the 1.8mw spec our friend mentioned is really true, then an itty-bitty 50ma or less wall wart would suffice... even at 18mw, such a device would work fine...

the wall warts that make noise are those types that are the little non-isolated switchers, as opposed to the older ' transformer/diode/cap types... stay away from those... most cell phone charging adapters are of this type and can be distinguished by their small size and feather weight...

just my 2 cents worth....

rgds,
ron g

That deserves a

(I would have just done the but for whatever reason when I tried all I would get was : D)

Cyclone82, it occurs to me your intent focus on getting an AC power supply for this little MV filter might come from concerns expressed in your other thread about a DataVideo TBC1000 power supply. In that thread, you mention a mfr rep for DataVideo told you the TBC draws more power when cleaning MV protection.

I can see how that might lead you to think the same power issue applies to these dedicated battery-powered MV filters. If that was your concern you can safely put it to rest: these are a totally different animal. The DataVideo (and other full-function TBCs) completely reconstruct the frame sync. In normal use, they are spec'd to handle typical tape glitches and sync drift when connected to a PC encoder. Their MV cleaning function is a byproduct of their primary reconstruction function: internally the DataVideo views MV as a *gross* distortion of a "normal" sync error. It then works much harder to rebuild the entire video signal around the intentional, much higher than expected error, which is when it needs a larger power cushion.

These mini MCM-type dedicated MV filters operate differently. They make no attempt to actually reconstruct or "fix" sync errors in totality: their sole function is to patch over or "mask" the MV corruption in one specific part of the VBI. This requires far less calculation and power draw, which is why they've been battery-operated since 1992.

The initial implementation of MV was a rollercoaster ride, as the studios desperately tried to stay one step ahead of black box filter mfrs. The first few filters were from reputable video accessory mfrs like VidCraft, and cost around $129. These were obsoleted almost instantly, as MV changed its strength and precise specs several times. The early filters could only be programmed once for a particular MV variation, when the studios changed MV the filter became ineffective. One by one the name brand accessory mfrs dropped out, as the products could not be guaranteed to work for more than a couple months.

At the peak of studio paranoia, MV was so strong it made some tapes totally unwatchable even direct from VCR to television (Universal's 1988 release of "Midnight Run" with Robert DeNiro being about the worst known example of MV contamination). Right around this time, a few enterprising independent filter mfrs began offering an "exchange program," in which you bought the filter box for approx $200 and could have the ROM chip swapped out as MV changed for a smaller fee of $50. This evolved around 1990 when one of these firms began offering a $329 filter they called "The Box" that had programmable ROMs, with a free 3-year update subscription.

The company went under about a year later when MV finally began aggressive prosecution of filter mfrs (which led directly to the DMCA shortly after). But the technology was copied and further evolved by Chinese inventors, eventually leading to very inexpensive filters with "smart" circuitss that could adapt to any reasonable variation in MV specs. The filters reached a plateau here, with the MCM design remaining the same since about 1992. The "smart" filter used newer circuits that drew very little power, allowing the elimination of expensive AC power circuits and wall warts, and a price drop from $99 to $49. The price stayed at $49 from 1992 until DVD completely replaced VHS around 2004, at which point these battery powered analog filters hit $24.95 and stayed there.

I've compared these little $25 pods to a number of pricier Sima-type digital filters (that also work for digital DVD CP) as well as "pro" TBCs from DataVideo, AVT, For. A, Hotronic, and Panasonic. In every case, the battery-powered filter was more transparent with less ill effect on the video. My oldest such filter is held together with a rubber band, the RCA connectors having been superglued several times over, yet it still beats more expensive boxes at the specific task of VHS MV cleaning. If you don't actually need the full-strength TBC to correct other tape damage, the battery unit is the way to go.