Friends of the Cumbres & Toltec - FriendsOfCumbresToltec.org

I dropped the gain down a bit. Please let me know if this helps or resolves the squealing sound that has sorely vexed and tortured wives and felines.

I hear many more sounds I attribute to the general workings around the yard, but no annoying whines....other than the turbo-generators on the engines. For me, the sound is great, I'm curious if your reduction of the gain cures the slight over-modulation I was getting when the locos passed the coal tower. Oddly, it seemed to be caused by the bell more than anything else.

For me, the additional sound quality is great and very much appreciated.

Thanks for working on the mic problem.
The whistle seems to have gone away.
The mic really makes a big difference to our overall pleasure of seeing what is going on in the yard.
Again thankyou,
Allan

Oh no!
The high pitched sound is back!
Since it seems to be intermitant (sp.), what else could be causing it?
Any ideas?

I haven't been watching much in the past 2 weeks. Been busy with work and a newborn. I just jumped on and I don't hear anything unusual. Did you hear it during the departure? (which i missed)

The only squeal/whine I've heard (last weekend) was the turbo on the locomotive. It's especially annoying when they're near the Tipple.

I'll try to keep the cameras running to hear this sound.

Ok, NOW I've heard the sound. I agree, it's not a turbo. Definitely sounds like feedback and it happened after the safety popped on a K36 at the Engine House. So, feedback was a real possibility.

I dropped the gain again and will continue to monitor as I'm able.

Well, I'm not sure what this is guys. I've heard it several times now and nothing I can do is making a significant difference. When I change the gain (and other settings), the sound stays the same, only a bit more quiet. And, I can see the sound on the DB level graph the camera gives me. This implies that the sound really is there and isn't feedback.

I can also hear what I assume is work being done in the Friends Wood Shop (old freight warehouse across from the Tipple) and the whine seems to correspond to an increase in sound from there. Maybe it's machinery in the Wood Shop?

I'm going to continue to monitor and see if the whine stops when the work stops this evening.

More input from ya'll (yes, I'm a Texan) is appreciated.

I haven't been on much all morning -- internet issues here, finally seem fixed. It was like dial-up days for me earlier.

Anyway -- the sound was never there annoyingly until yesterday afternoon. When I tuned in during the night at all, and I often do, and also very early this morning, there was no whine at all. This kind of goes along with what you said above about the work ending in the evening. Just as a note - and perhaps from whatever you did -- the overall volume seems much lower this afternoon.

Larry Sullivan wrote: Just as a note - and perhaps from whatever you did -- the overall volume seems much lower this afternoon.

Thanks, Larry.

The gain is lower. Doesn't have to stay this way. I'm experimenting.

Ok......I just noticed "the sound" for the first time. It sounds like a saw or a lathe turning something large and metallic....it fades in and out and almost like sound from a distance. Anyone know if any large metal parts are being turned or worked on in the engine shop?

OK Jason.....now I get a clicking or ticking noise from the North Cam. Almost sounds like it's a field related....interference from a loose connection or unshielded device nearby. Definitely north camera only. Is this maybe that temporary wiring that was mentioned?

That clicking sound has been there on the north cam since the work was done. I'll address it the next time I'm in town.

From the sounds of it (pun intended), it's either an impedance mis-match or something weird with the ADDA conversion at the point of the server, or (worse) combination of both. There is also a definite a phasing problem: The tone (About 1.7kHz) has a secondary that's maybe a half a cycle lower or higher. So, sometimes the two are in phase and double the volume... and other times they completely eradicate each other. It could also be that the video camera system requires the external mic to be balanced... and the one installed is unbalanced (or vice verse). I think I''d start with looking at the impedance requirement. It could be the system is at 50k Ohms or above (way above) and the mic is only at 300 to 600 ohms. This mismatch could easy produce the nasty tones we're hearing. Dave.

Jason Rose wrote:Well, I'm not sure what this is guys. I've heard it several times now and nothing I can do is making a significant difference. When I change the gain (and other settings), the sound stays the same, only a bit more quiet. And, I can see the sound on the DB level graph the camera gives me. This implies that the sound really is there and isn't feedback.

I can also hear what I assume is work being done in the Friends Wood Shop (old freight warehouse across from the Tipple) and the whine seems to correspond to an increase in sound from there. Maybe it's machinery in the Wood Shop?

I'm going to continue to monitor and see if the whine stops when the work stops this evening.

More input from ya'll (yes, I'm a Texan) is appreciated.

It does seem to correlate with activity, but my speculation is that it's resonance: There's an echo that, with sound of a particular frequency, creates a standing wave. If that's true, messing with the volume would have no affect but changing the position or maybe the orientation of the microphone would. <Shrug> But that IS speculation. I know nothing.

be well,
bob roman

Today should provide some good "data" as the yard will be busy with train movements while the wood shop (just out of view of the south camera, across the yard tracks) will most likely be closed for the holiday) For what it's worth, when I've heard the noise it did sound to me like wood working tools.

Bob and Dave, thanks for the detailed information. I'll dig deeper when time permits.

Jason, since the RR uses 3 phase power, it might be a problem of some of the equipment being on one leg of the power (ie. phase 1) and some being on another leg( ie. phase 2). I believe this is called phase looping.
This might be remote but possibly some thing to check out. It has been a loooong time since I studied 3 phase power or how to address this problem.
Allan

AS an afterthought, It might possibly be equipment that is not properly isolated in the woodshop. This might explain why high pitch sound seems to be more prevalent when the workshop is being used.

Allan, I don't know much about power. But several Friends do and they worked on the components needing power.

The cameras and mics are PoE (power-over-Ethernet),so shouldn't be affected by traditional power issues.

Thanks Jason,
It was just a thought.

Allan

I just checked in and it's whistling again so I guess it's not coming from the wood shop (unfortunately). Since guessing is all we can do from a distance, how about the noise is a harmonic of the fan?

I was about to comment on how there's no noise today, then I see Rich's post.

I've watched for two full cycles here, so about 20 minutes and getting nice clear sound, lots of birds, traffic noise and occasional metal bang coming from the shop, but no whistle noise at all. This morning I was on early during the morning preps and didn't hear anything bad, as well as a few checks overnight hearing nothing. Very slight background buzz, but that I think is one of my speakers, as when I mute the cams I still get that buzz.

Anyway -- much improved at least to me.

Hope all are having a happy 4th!

For the first time since last Thursday the sound is back this afternoon. So I really do think it has to be the wood shop, or some machinery that wasn't used all weekend. It's also not as bad as before, so whatever adjustments you made Jason make it a tolerable noise. Quite happy to live with it, with all the other benefits we now have!

I had the cameras running all weekend and never heard it. I wasn't watching the whole time (I do have a life), but I had my office sound system cranked up so I'd hear it when I was elsewhere in the house.

I agree that it seems to be connected with the woodshop or something else that is being done nearby.

The local dentists drilling for cavities ? Dr. Hertzya and Dr. Yanksum