ClearCom RM-440 with problems

Jay Ashworth

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Feb 7, 2014
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St Pete FL USA
So, pursuant to a couple other of my recurring threads, I just bought this:


having read the condition description, and knowing that older Clearcom wired gear is *prone* to get noisier when you turn the level down, whether there's incoming audio or not.

Anybody got any ideas on the other problem the seller notes, about the audio being distorted? Could that be unterminated lines on the 2w side? Blown headset for test?

I don't remember that from the Intercom Engineering Handbook (an *exceptional* piece of free PDF's-manship, if you've never read it); maybe it's time to read it again.

I have a known-working system to hook it to, and a known-working PH-88, so we'll see when it gets here next week.
 

themuzicman

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Honestly there isn't enough data to know whats going on. Half of me would immediately say the noise is on the output side because typically Clearcom issues just hit a single channel, however if the input channel volume knobs are the knobs referenced in the product description than that would chart as a channel issue which throws me. However, If you zoom in you'll see every DIP switch is engaged which isn't standard procedure. If I had to guess potential reasons in no particular order:

For this Hiss:
1. Program is engaged, Program input could be noisy
2. Program Interrupt is engaged, could it be just boosting the noise floor of the Program input? (Probably not, this is also assuming the Program tiny tiny volume knobs under the channels are cranked evenly across all 4 channels and I'm not getting that from the picture, but I also can't say that isn't a potential issue).

For the Distortion (again, it'd be really weird for the same problem to manifest on 4 channels like this if it wasn't an output stage issue!)
1. Unterminated or Double Terminated line
2. Nulling Circuit's are dialed in really funky and never fiddled with when this seller went to test+sell (honestly the most likely culprit if I knew it was just 1 channel)
3. Side-Tone Adjust is dialed in too hot (going to assume seller did the 1-person test where you connect two units, shout into the first to hear yourself)

I popped thru the Seller's page and they aren't selling basic gear, they have some stuff that would imply to me they either worked in NYC theater, run their own rental shop, or have some connection to rental shops to buy old gear for resale -- I'd love to be able to make a big assumption that the seller actually knows how to troubleshoot intercom based on the other stuff they are selling, but intercom is intercom and that is never a safe assumption. Once you get the unit, flip all the DIP switches down (including line-length, I just always set it to long), engage just what you need, turn Program potentiometers all the way down, connect it up to a working good system and go to town!
 

Jay Ashworth

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St Pete FL USA
Yeah, that was about what I thought; and my appraisal of the seller was about the same as yours: clearly, it was *possible* for them to test and diagnose it, but that doesn't mean what they heard wasn't their "own fault".

In my house, in these COVID days, I need to be able to bring the A and B loops from my control booth, the C loop, possibly from my blackbox, and the D loop to my camera people, all onto my desk, and this (and the MS812 I would have preferred) are the only CC boxes big enough to do it.

A, B, and C all have their own power, and D will get power from the box I've been using to date*, on which I could only bring A in as Program audio, which worked nicely, but was frustrating as all hell when I couldn't talk back to people.

Thanks, Muze.

[ * And hence it's good this is an RM-440, and I don't have to buy 3 isolators at a bill a piece ]
 

themuzicman

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A, B, and C all have their own power, and D will get power from the box I've been using to date*, on which I could only bring A in as Program audio, which worked nicely, but was frustrating as all hell when I couldn't talk back to people.
The RM-440 should only be powered from 1 source...not saying it won't work, but I don't usually have too much luck, unless I'm running a full 70x or 90x series system, powering a clearcom system from multiple sources. Pin 2 drops are your friend here, but you lose the ability to call.
 

Jay Ashworth

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I'm not sure how the hell you *could* do that -- it's an RM, not an MS, and it has to *expect* that all 4 channels are going to be powered *somewhere*, right? Every loop has to have power. RM's *do not supply power at all*; they don't even have a power supply -- they're line powered.

I assumed -- I have the manual, but am not done reading it yet -- that they took power from Channel A, and you were compelled to use that Channel first.
 

themuzicman

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I'm not sure how the hell you *could* do that -- it's an RM, not an MS, and it has to *expect* that all 4 channels are going to be powered *somewhere*, right?
What I mean to say is that you should only power it from one main station, one common source of power for all 4 channels -- don't pull 4 different mainstations of power into 1 remote station.
Sometimes it works, but more often than not you end up with what I like to call "whale noises" on the line from the offset between the various power supplies. The 700 series PSU's fix that by regulating the power supplies with a microcontroller so you can link and daisy and do stuff which makes redundancy wonderful, but on the older stuff you may just get whale noises by trying to power a remote station from multiple PSU's.

Some models you can do separate power on A/B and C/D (and the switchboard stations split power down 1-6/6-12 in addition to A/B C/D), but as long as your mainstation has the power headroom, 1 channel of intercom with power will provide power to all 4 channels of the remote station. If A/B/C all derive from the same mainstation then they are all cool to stay powered, but if they are all from different systems just drop Pin 2 on all but 1 channel.
 

Jay Ashworth

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St Pete FL USA
What I mean to say is that you should only power it from one main station, one common source of power for all 4 channels -- don't pull 4 different mainstations of power into 1 remote station.
Again: I can't see how you could do that.

Each loop has to have power. This is a remote station: an RM. It doesn't supply power to *any* of the 4 loops.

Each of the 4 loops is separate, and must have its own power, that has to come from *somewhere*.

In our case, A and B are coming from a FreeSpeak II I've mentioned before, but *both are powered*, and must be, because some beltpacks are only on one of them.

Sometimes it works, but more often than not you end up with what I like to call "whale noises" on the line from the offset between the various power supplies. The 700 series PSU's fix that by regulating the power supplies with a microcontroller so you can link and daisy and do stuff which makes redundancy wonderful, but on the older stuff you may just get whale noises by trying to power a remote station from multiple PSU's.

Some models you can do separate power on A/B and C/D (and the switchboard stations split power down 1-6/6-12 in addition to A/B C/D), but as long as your mainstation has the power headroom, 1 channel of intercom with power will provide power to all 4 channels of the remote station. If A/B/C all derive from the same mainstation then they are all cool to stay powered, but if they are all from different systems just drop Pin 2 on all but 1 channel.
I should probably be clear that this will be the only multi-channel box in the building, except the FSII packs, which obviously don't count here...
 

themuzicman

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Again: I can't see how you could do that.
Does this poorly done drawing show you a better example of what I mean? I don't know how many different ways I can use words to explain that I both know exactly what a remote station are and to prove that this setup isn't a good idea...

Note the 3 power-generating devices on the left side going into the 1 device that does not generate its own power on the right side. You need to make sure that only 1 of the things on the left is actually feeding current into the thing on the right. FS-II-Base-II can function as a powered base station for a small number of devices, it too is a mainstation if you don't disable that feature.
 

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Jay Ashworth

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It sounds to me like you are saying the RM-440 was poorly enough designed that it will misfunction in a condition that's not at all uncommon... or that I'm badly overestimating how often people want to do this.

Clearly, all 3 devices on the left *must* generate power, or their own strings of local 2w boxes won't work, right?
 

themuzicman

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It sounds to me like you are saying the RM-440 was poorly enough designed that it will misfunction in a condition that's not at all uncommon... or that I'm badly overestimating how often people want to do this.

Clearly, all 3 devices on the left *must* generate power, or their own strings of local 2w boxes won't work, right?
It's not very common on smaller PL systems at all, that's why Clearcom has always sold larger Matrix offerings alongside its 4-channel PL. I wouldn't say that Clearcom designed their product poor at all, their response would probably be that you are using the product in a manner it was not designed to be used in. The answer is very simple, Pin-2 drop and you lose the ability to use the call light.

If you're working in a large multi-venue space Clearcom would probably recommend one of its matrix products, this is the reason the Eclipse frames come in several sizes.

In NYC Theater world we refrain from using Eclipse by using Switchboard Stations in a manner they shouldn't be used in (eg SB-704) - 4 channels, A/B/C/D, and then 12 Switchboard Slots that can matrix onto A/B/C/D. In the real world you would pull discreet lines to the Switchboard and matrix those lines to whatever channel you wanted them on - the switchboard sends that channel down that line. You gain the ability to quickly move folks from channel to channel, and you get a nice short light to see if someone has shorted out their pack. Very useful if you're working outdoors and folks forget to hang up their wired intercom in dryboxes. However, if you keep the output on the switchboard at the very top not actively tied to a channel it will just shoot power down the line without attaching to A/B/C/D and you generate a fake intercom channel. This is how I'll have 16 channels of intercom on a large musical without investing in a proper matrix.

I know the multiple power source thing only because a few times in my life the rental shops have been out of Switchboard stations and you cannot just make due by slamming in 4x MS-440's into a rack and calling it a 16 channel intercom system.
 
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Jay Ashworth

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Got it.

Sadly, I haven't got any real choice; I'm overhire, and it's *me* who thinks the three independent PLs, deployed for separate purposes, and which only occasionally need to be tied together, need to be tied together, and I don't carry that much water there.

So I'll make do as best I can, I guess.
 

TimMc

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Feb 15, 2017
Got it.

Sadly, I haven't got any real choice; I'm overhire, and it's *me* who thinks the three independent PLs, deployed for separate purposes, and which only occasionally need to be tied together, need to be tied together, and I don't carry that much water there.

So I'll make do as best I can, I guess.
Let us know what happens, Jay.
 
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Jay Ashworth

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St Pete FL USA
Well, it has arrived.

I plugged A into a live circuit, and the front panel behaved about as I would expect. In the headset, I had noise (static, quite loud) from the lowest setting on the volume knob, then a very short burst of something else, as I kept turning, then effectively silence the rest of the way up.

Talk buttons lit as expected, listen buttons didn't affect the noise, could not hear someone on the loop at either end of the Volume range. He couldn't hear me either.

All the electrolytics look ok on this 1995 dated board, all the ribbon connectors seem seated ok.

I noted some of what looks like partially evaporated flux on the C and D listen buttons (and maybe one talk button).

I tried plugging the powered circuit successively into B, and C, and D, and it behaved... less well; the talk buttons flashed on and off, and things like that. (And yes, I had turned off the dip switches on the sub panel as suggested -- assuming that "towards the case" is off; if not, I just turned them all *on*. :)

I don't suppose there still exists a service manual for the RM-440?
 

Jay Ashworth

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Or alternatively, what does ClearCom charge to fix such things; it still has to be less than the $1900 discount I got on the auction. :)

(Or does someone in Tampa have a bench and Clearcom knowledge, and want to quote me a price, in dollars, good beer, or both?)
 

TimMc

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Well, it's as represented so there were no surprises.

Give Clear Com a phone call on Monday. Their web site doesn't know the RM-440 existed.
 

Jay Ashworth

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Feb 7, 2014
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St Pete FL USA
Apparently Mark, at Clear Com, is the guy who knows where all the bodies are buried on the PL line of gear... and he's due back from vacay tomorrow. So hopefully I'll hear from him this week.

If anyone has someone else's bench to refer me to (I know my limits :)), let me know. SEAL in Orlando still have a bench?
 

themuzicman

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If anyone has someone else's bench to refer me to (I know my limits :)), let me know. SEAL in Orlando still have a bench?
Give a shout to PWS, if their Orlando office is anything like Masque up here there's just a room of intelligent EE people you can throw various things in front of and they'll poke at it until it works.
 

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