channel one VU meter

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bachelorb

bachelorb

Cowboy Chord Virtuoso
.......Well I'm not out of the woods yet on this Tascam 244. Testing out the unit, I get sound into the headphones, and the channel 1 overload led works, but there is no movement with the VU meter (the meter does light up). I don't have a 244 schematic but I do have a 246. Unfortunately, the meter connector doesn't 't look the same as on the 244.

Anyone have any ideas?

Thanks,

Brad
 
Best thing to do is to route test tone to the buss associated with the meter, then check to see if you have tone at the input of the meter coil with your multimeter set to AC volts. If you have signal at the meter coil input, the meter is shot. Time to replace. If there's no signal, the problem lay upstream of the meter.
 
Thanks SB.... I didn't get a chance to look at it today (After a couple of days of replacing parts, I took a recording day).... I will tomorrow though.

I forgot to mention that meter 1 doesn't work when I'm recording, or mixing down.... Does that matter before I pull all those panel knobs off again....
 
It sounds like your meter is dead in all conditions in which it should not be.

The test I suggested above is to determine if the problem is:

A. With signal getting *to* the meter, or
B. The meter coil itself is teets-in-the-air

With 'A' the task then becomes where it is signal integrity is broken. With 'B' the task becomes sourcing a replacement meter and putting it in.

In either of these cases, the patient will need to be opened up.

Hope that answers your question.
 
I would expect ALL VU mc meters to "blip" at least once at start up or power down. If yours never moves at all I would suspect an O/C coil. Even if the drive amp was buggered there would still be a pulse through a coupling cap from Vcc.

Dave.
 
Thanks guys..... It sounds like I need a new meter. I just did an internet search and found one in Great Britian that seems reasonably priced. I have to message the guy to see if he can send it across.

allow me to whine for a minute......


My "bench" is our dinette table. which I have been informed by my wife is available between the hours of 8-noon, 1-6, and 7-11pm. After 11 are trailer quiet hours, so I have to keep the cursing to a minimum..... so everything has to happen within those time periods (believe me..... I deserve these restrictions....). In those "working hours", my wife's cat patrols my bench, looking for any and all components to play some kind of cat hockey game because in the cat's mind no tools, knobs, belts, or other components are allowed on the "bench" which I guess we share......

Killing the cat is not an option (....another wife rule.......)

The other problem with this nomadic life is ebay decides when and where to accept an address. This RV park has been here 50 years, but getting ebay to send a package here is impossible. It says it is an unrecognizable address. This has probably saved me 100's of dollars in bad decisions this last month, but still....... its frustrating......

....end of whine.......

Thanks for the help so far.......

Brad
 
That's definitely something that I hadn't thought about with regards to the RV life. I know my wife would never go for it, so it's pointless to dream about it, but I still do have visions of it every now and then. But with the amount of things I buy (and my wife, for that matter) online, that would certainly be a real issue.
 
Well.... the rant is over so I'm trying to get back on track. I started playing around with the test tone and checking out individual channels. In 4 ch rec mode everything is fine. In Sync mode 1,2, and 3 are fine, but when I plug the input into 4, the test signal is weak. I do have the manual.... guess its time to work my way through it. I just don't know where to start
 
bachelorb said:
Well.... the rant is over so I'm trying to get back on track. I started playing around with the test tone and checking out individual channels. In 4 ch rec mode everything is fine. In Sync mode 1,2, and 3 are fine, but when I plug the input into 4, the test signal is weak. I do have the manual.... guess its time to work my way through it. I just don't know where to start
Click to expand...

What sort of test equipment do you have? I do not really have my head around the problem yet (and tis early here still!) but try this and report back.

Record the same tone to each track (you may have to cobble up some sort of splitter cable/box) setting each track to say neg10VU. Play that. Do you get neg 10 back on the meters or/and from the replay outs?

If so check the sync output. If trck 4 is missing, take the tape off and flip it, upside down. Is 4 still down? I suspect it must be and you need to investigate that part of the circuit but if sans scope and a decent AC mV meter you will struggle.

Dave.
 
Here's what I was able to do. This is my test tone
image.webp

This is how I had the 244 set up. (If it's upside down, please click on the picture) . I'm pretty new to this, so If the setup is why ch 1&3 are quiet, let me know.

image.webp

What I ended up doing was moving the tone to different input jacks, then turning on the mic/line switch. Each on/off corresponds to the different tracks. Channels one and three barely can be heard on the tape, where they come through loud and clear when I'm just monitoring them in the headphones. Channels 2 and 4 sound the same in the headphones as on the tape. Channel 4 has a buzzing sound with very weak tone

Below is what was recorded on the tape (you can barely hear the first tone, but channel 2 is VERY LOUD... Channel 3 is very quiet..... Channel 4 buzzes . You may want to listen first at a distance)




This was interesting.... This is channel 4... the signal degraded a little after I switched it on....
image.webp

Two other notes.

1. I had turned off the 244, but accidentally left the test tone on plugged into channel 4. I turned the machine back on and heard the tone coming through the headphones clear as a bell as if it were on channel two... I unplugged it, and plugged it back in, and I had the weak fuzzy tone again.

2. I recorded the test tone on another Portastudio and tried to record all four tracks at once on the 244. I thought I had hooked it up wrong when I listened to it back, but I think now that it was doing the same as above and I couldn't hear channels 1&3

***Edited to add- Equipment wise, I have a good meter, , all the apps Apple will let me have, and two years of high school electronics 36 years ago to draw from****
 
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Well today I went back and tested the tone using the Sync mode. Again, Channels 1 and 3 are not functioning properly. I guess my plan of attack is to troubleshoot upstream of the individual channels, where they tie together in the BUSS mode....
 
Re: channels not recording good signal.

Make sure the heads are spotless. Really clean. I've always been suprised how little dirt on the heads can drop the signal to next to nothing.
 
RFR said:
Re: channels not recording good signal.

Make sure the heads are spotless. Really clean. I've always been suprised how little dirt on the heads can drop the signal to next to nothing.
Click to expand...

Thanks.... I cleaned them with alcohol and demagnatized them after this post. I'd been meaning to do that, but I'd forgot..

I've started troubleshooting and checked the first test point. all voltages were fine except channel 4, which I was kind of expecting due to the muffled fuzzy sound. Well, I was running through and double checking and I touched the input to 4 and the test tone from the headphones come through clear as a bell. I went back and checked 4's voltage again and it was in line with the other 3 channels.

OK!!! Progress ....I thought. Sprayed contact cleaner inside the input jack and worked it back and forth and it worked.... until I touched it.. fiddled some more with it and it would work intermittently then it would just stay with the muffled fuzzy tone. Sprayed it again with the same results. Clear tone and good voltages at first... then it goes away. Sooo it's a bad input jack I thought..... and then I turned off the unit.

Just when I turn it off, the test tone comes through clear again.... everytime......

I turned it on again, the test tone was clear until I touched the jack, then it became muffled and fuzzy again. I repeated this a bunch of times.

I'm thinking now its not the input jack.
 
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