# Old Clear-Com Question

#### Electric Carpenter

##### Member
Hey Everyone,

This is my first post so bare with me... but!

The facilities I am working in right now just came across with a pretty big problem last night in tech with our clear-com system. We started to randomly getting a high pitched squeal through the entire system, almost like a "fire alarm or CO2 detector running out of battery" beep in our ears. It was the worst thing in the world.

At first we started to take some packs out of the system, but nothing was working, it kept randomly happening, and getting worse.

The one place we did not trouble shoot was back in the pit where the conductor also has a pelt back and headset. Come to find out his pack was running through the orchestra snack back to the sound board and into the clear-com system, is this why?! The person who set this up did this and I have never seen this before. Also, we added the full pit last night and it started last night, which was the only thing we changed from two nights ago and last night!

Any thoughts would be greatly appreciated!

#### MRW Lights

##### Well-Known Member
sounds like a feedback loop has been added to the chain. The routing of that headset sounds like a convenience issue that may have been hooked up incorrectly or someone may have a misunderstanding of how program feeds work. Without more information these are my shots in the dark.

If the last thing that changed was the orchestra I would check the conductor's pack and make sure they're not taking it off and leaving the talk button latched. The fastest solution may simply be helping someone be aware of an inadvertent error. Depending on the base station if you have a remote kill you can also be listening for this to occur and then close all mics when it happens which should get rid of it, but everyone who needs to talk will need to press their talk button again.

#### themuzicman

##### Well-Known Member
The one place we did not trouble shoot was back in the pit where the conductor also has a pelt back and headset. Come to find out his pack was running through the orchestra snack back to the sound board and into the clear-com system, is this why?! The person who set this up did this and I have never seen this before. Also, we added the full pit last night and it started last night, which was the only thing we changed from two nights ago and last night!
This is very common, Keys 1/Conductor almost always gets a Clearcom belt pack at their location, via a turnaround in the Pit Snake.

I would re-null your system (typically I have a single person null out every location themselves) and then post someone at your Main Station and do a channel-by-channel, user-by-user check of the system to see where the fault lays with a second person visiting every belt pack or remote station in the system.

#### Electric Carpenter

##### Member
Thank you both so much! We did some investigating today and we think the conductor headset, which is one of the phone handheld ones, was being held on, causing feedback due to his volume. We have take some precautions for the next rehearsal and hope we can find a solution!

#### EdSavoie

##### Well-Known Member
Just as a side note for anyone who may stumble on this thread, I've seen an older base station misbehave and have the microphone gain go off the charts, to the same feedback effect.

I've also heard the same thing happen moments before the Director's beltpack started burning.
(I do suppose that's what directors get for being on coms, but still.)

#### RonHebbard

##### Well-Known Member
Just as a side note for anyone who may stumble on this thread, I've seen an older base station misbehave and have the microphone gain go off the charts, to the same feedback effect.

I've also heard the same thing happen moments before the Director's beltpack started burning.
(I do suppose that's what directors get for being on coms, but still.)
If any channel loses its termination, its gain will rise radically to the point of feedback.
A practical example of this occurs whenever you unplug a belt pack from a system with its mic live and its headset NOT on anybody's head. You get a momentary brief burst of feedback from the headset's earpiece from the time the termination is removed from the audio lasting only very briefly 'til the belt pack discharges and dies from lack of power.
I'm talking 'old school' party line Clear Com here, not new digital packs.
Toodleoo!
Ron Hebbard.

#### themuzicman

##### Well-Known Member
the phone handheld ones, was being held on, causing feedback due to his volume. We have take some precautions for the next rehearsal and hope we can find a solution!
If you're coming out of a rental shop, ask the shop for an HS-6 hangar, and then take some tie-line and clove hitch it to a spare mic stand.

#### Aaron Becker

##### Well-Known Member
If any channel loses its termination, its gain will rise radically to the point of feedback.
A practical example of this occurs whenever you unplug a belt pack from a system with its mic live and its headset NOT on anybody's head. You get a momentary brief burst of feedback from the headset's earpiece from the time the termination is removed from the audio lasting only very briefly 'til the belt pack discharges and dies from lack of power.
I'm talking 'old school' party line Clear Com here, not new digital packs.
Toodleoo!
Ron Hebbard.
Oh man. I still use party-line. That must make me old! ahh!

#### EdSavoie

##### Well-Known Member
I'll second that one, haven't seen any newfangled digital packs in real life yet.

#### Aaron Becker

##### Well-Known Member
I'll second that one, haven't seen any newfangled digital packs in real life yet.
I have seen them, as a digital party-line. haha

#### EdSavoie

##### Well-Known Member
The newest I've seen are the RS 700 series of beltpacks we rented to supplement our aging RS 500 system.

#### Aaron Becker

##### Well-Known Member
The newest I've seen are the RS 700 series of beltpacks we rented to supplement our aging RS 500 system.
I still use RS 500s on a regular basis. Those things are workhorses!

#### RonHebbard

##### Well-Known Member
I still use RS 500s on a regular basis. Those things are workhorses!
@Aaron Becker We've got at least three amateur groups in our area still regularly running the original, stainless steel [with gooey black potted PCB's] RS100A belt packs, although I will admit to having changed call light lamps at least once per pack.
Toodleoo!
Ron Hebbard.

Aaron Becker

#### EdSavoie

##### Well-Known Member
Well they charge so much for them it's easy to understand why we don't let go!

Also, I previously mentioned that our RS 500s were "aging" as we've lost two packs to self combustion, and two to a peaceful failure.

That and our base station desperately needs to have it's little potentiometers recalibrated.

#### RonHebbard

##### Well-Known Member
Well they charge so much for them it's easy to understand why we don't let go!

Also, I previously mentioned that our RS 500s were "aging" as we've lost two packs to self combustion, and two to a peaceful failure.

That and our base station desperately needs to have it's little potentiometers recalibrated.
@EdSavoie What's failing / burning in your 500 series packs and I'm not understanding what needs "recalibrating" regarding your base station's packs. Please 'splain. [And exactly which pots?]
Toodleoo!
Ron Hebbard.

#### EdSavoie

##### Well-Known Member
Well, the two packs that died violently were a touch too chared to tell what was at fault in the first place. My guess based on the char-iest components is that either a transistor or adjacent resistor released the smoke first, encouraging others to do the same.

One of the ones that died silently was repaired by a local shop, the other one "wasn't repairable". Unfortunately I wasn't able to learn what it was that had failed.

The base station has potentiometers inside to calibrate various things, which I'm not entirely familiar with. One of the pots is for calibrating the base station's microphone gain, which is currently far too sensitive and needs to be adjusted. This is primarily what I'm referring to.

My original theory was that the base station was responsible. While the repair shop ruled that out, they replaced most of the capacitors as a preventative measure, (which seems to have knocked the aforementioned mic gain out of whack...) and I've heard no reports of subsequent failures since.

Nor have I heard of any directors getting on headset since...

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#### RonHebbard

##### Well-Known Member
Well, the two packs that died violently were a touch too chared to tell what was at fault in the first place. My guess based on the char-iest components is that either a transistor or adjacent resistor released the smoke first, encouraging others to do the same.

One of the ones that died silently was repaired by a local shop, the other one "wasn't repairable". Unfortunately I wasn't able to learn what it was that had failed.

The base station has potentiometers inside to calibrate various things, which I'm not entirely familiar with. One of the pots is for calibrating the base station's microphone gain, which is currently far too sensitive and needs to be adjusted. This is primarily what I'm referring to.

My original theory was that the base station was responsible. While the repair shop ruled that out, they replaced most of the capacitors as a preventative measure, (which seems to have knocked the aforementioned mic gain out of whack...) and I've heard no reports of subsequent failures since.

Nor have I heard of any directors getting on headset since...
@EdSavoie Isn't that why ClearCom invented their HS6? [Due to director's heads being too swollen to be encompassed by headsets sized for mere mortal minions?(And in white so blind directors could find them in the dark?)]
Toodleoo!
Ron Hebbard.

#### gafftaper

Senior Team
Fight Leukemia
By the way, if you get around to needing any replacement gear, I'm a big fan of Production Intercom... now renamed Pro Intercom. http://prointercomllc.com/ I've used their beltpacks and Headsets and love them especially the tiny BP.15 beltpack and the SMH 710 headset (light weight, comfortable, $80, and fairly durable considering how little is there). I haven't used the base stations but if I remember right @Van has and was very impressed with the quality at a lower price. Check them out. Van #### RonHebbard ##### Well-Known Member Premium Member By the way, if you get around to needing any replacement gear, I'm a big fan of Production Intercom... now renamed Pro Intercom. http://prointercomllc.com/ I've used their beltpacks and Headsets and love them especially the tiny BP.15 beltpack and the SMH 710 headset (light weight, comfortable,$80, and fairly durable considering how little is there). I haven't used the base stations but if I remember right @Van has and was very impressed with the quality at a lower price. Check them out.
@gafftaper I've installed three of their 2RU 'bare bones' power supplies, a redundant pair in a PAC and a single in a local amateur group's venue and can attest to them being solid, durable and reliable. I will note I diode coupled the outputs on the redundant pair so the DC indicator would extinguish if one of the units failed or was inadvertently switched off. Without external summing diodes, both supplies' DC output indicators remain lit so long as either is producing output.
Toodleoo!
Ron Hebbard.

Van

CB Mods