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Re: Long cable questions

Subject: Re: Long cable questions
From: "Rich Peet" <>
Date: Fri, 22 Aug 2003 14:42:25 -0000
note my additions inserted within original text.

--- In  "Steve Pelikan" 
<> wrote:
> Thanks to several of you for suggestions about sticking a mic out 
on a
> mudflat and
> running a cable back to a recorder. This sounds like a "grown up" 
version of
> what I did when I put a mic next to
> a Carolina Wren nest (in our eaves) with a long enough wire to 
reach a
> recorder. (Worked like a charm.)

I can't say I am a "grown up" as I am still playing.

> 
> This is also one of two approaches I've considered to recording 
Prairie
> Chickens (or Spruce Grouse) on a lek.

I botched the last Prairie Chicken lek I recorded as well but did get 
some good mono recordings.  Things to keep in mind for the next time 
you try are:
1. These guys are very loud and can easily surprise you on pre-set 
gains for drop and return.
2. It is not a good event to try and record with a parabolic. This is 
because you are capturing four different types of sound at once. The 
throat "hum", the chicken "squack", the foot "thumping", and 
the "collisions" during the display. In making your setup keep in 
mind that the "hum" is projected or thrown. The direction will sound 
as if it is comming from any large low object near the lek and not 
from the bird.
3. The best bet for recording is to reserve a blind inside of the 
lek. There are a few available and mics can be set up before on the 
roof. I do recommend the roof and not the ground because of 
the "hum".  If you want me to post a sound example of an active lek 
just let me know and I will.

As far as Spruce Grouse, I recommend that you walk up to one. Grab it 
by the feet and hold it in front of the mic :)


> The other approach I thought of was to dump the recorder and mic on 
the lek
> long before dawn. Turning it on might be a problem (though I 
thought maybe a
> radio-control would be possible), so my plan was to use an MD set 
in "long
> record mode"  that would do almost 4 hours in low quality mono, and 
hope the
> birds started before the batteries died or the the disk filled. For 
my one
> chance, (I don't live near any leks) it got very cold overnight and 
the
> batteries died long before there was any activity, even though I'd 
but the
> recorder in a styrofoam box. (Perhaps a small heater?) But the 
moring was
> calm and clear, the sun rising behind us, and the displays, viewed 
through a
> scope from about 1/2 mile were wonderful, so I have no regrets.
> 
> My questions, then, are:
> 
> 1. How long a cable can I hope to use? I assume it should be 
shielded? Do I
> need an extra "repeater" or "amp" to use a really long cable? Is it 
enough
> to get inexpensive, shielded (3-conductor) wire and solder (I've 
learned to
> do that now!) connectors on each end, or are there other things to 
consider?

Balanced line outside I have gone to 100 yards without any notice of 
loss.

Unbalanced I have gone to 150' outside without noise or loss using 
good mic cable.

No further preamp needed.

If you are going to play with cheap telephone wire for mic wire, do 
not make the mistake I did. Stay away from aluminum foil shield. The 
stuff breaks very quickly in field use. Just avoid aluminum in any 
cable like the plague.

> 
> 2. What about my idea of sticking a recorder out near the birds and 
turning
> it on from a distance? Have you tried it? Can anyone offer 
suggestions about
> how to do it?

For minidisc, the remote unit is looking for a specific resistance 
for each command across the two active pins. A remote garage door 
opener circuit could easily switch a relay to switch in the resister 
for record. You want only a momentary contact. Let me know if you 
have success. Minidisc.org has the info for the resister values and 
if you have trouble finding it I have the Sony values around here 
somewhere.

> 
> 3. My first recorder (a hand-sized Sony) had a "voice acitvated" 
recording
> system that would start recording at either one of two user-
selectable sound
> levels. When I tried sticking it next to an American Robin nest, it 
switched
> on and off too fast to make a useful recording. Has anyone 
considered /built
> improved versions of this sort of system? I guess I could program a 
laptop
> to start recording at a given level and keep going for a while. Or 
is there
> a way to "fiddle with" commerically available voice-activated 
recording
> systems to adjust when they turn off? Could I use one of these 
(cheap, I
> hope) systems to turn on recording by a higher quality recorder?
> 
> As always, I look forward to everyone's suggestions and insights. 
With all
> your help, someday I'll start to think I know what I'm doing!

My cheap designs altering electronic kitchen count down timers have 
not yet been successful.  I am still working on that. The problem I 
am currently overcomming is in making a single mommentary resistance 
as the alarm keeps pulsing.

adjustable level vox is available for laptop recording and I do use 
that.


> 
> Thanks,
> Steve P



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