I will try an electricians supply store this week. They will probably have
it (flux). They were closed when I was there, so I couldn't ask them.
I did solder the shield to pin1 only on all my new cables and the cellphone
signal pickup problem was gone. I'm very satisfied with that. I don't know
if that is the right way to do it, but it worked for me. I haven't analyzed
the recordings on my computer yet, but it sounded great.
I tried to use another TR connector on the hydrophone. I had an angled
Neutrik TR connector at home, but it sounded even worse I also tried to use
a 3-pin XLR soldered in different ways but that didn't work either. It
sounds like a strong hum or like if it's not grounded. When I touch the
connector or cable the problem gets worse or better, so it should have
something to do with the ground?
You had a problem with damp earth? I have made one 15 meter and one 50 meter
extensions now, so I probably need to figure out a way to protect the
xlr-connectors when I use them together from damp ground or if it starts to
rain. It should be an easy way because I don't use permanent installations.
Just a few hours or so, so I need a temporary solution. A plastic bag and
electricians tape is probably the easiest way?
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Datum: Sun, 13 May 2012 01:44:57 +0100
Ämne: Re: [Nature Recordists] Best way to build simply DIY stereo mics.
> I tried to buy some flux at three different places here locally, but
> none of them was selling flux.
Have you tried electricians suppliers? You can use plumbers flux if is
a non-acid type.
I soldered up some RCA connectors today and the cored solder didn't
"tin" the tags without extra flux.
> One thing I noticed is that the shield that is soldered to the pin 1
> on the connectors is then "bridged" to the XLR's earth/shield on the
> edge of the XLR connector. Does that make it use recorder as the
> earth/shield? Is it good or bad to do it like that? Does the cable
> get more or less sensitive to cellphone signals?
We discussed connecting the shells a little while ago.
The golden rule is to ground a circuit only once, usually at the
mixer/recorder end. If it is grounded twice to different points you
can get comparitively high currents flowing through the shield. The
complete circuit makes a single turn loop and any AC magnetic fields
will set up current in this loop.
Mains is at +41dBV in America, +47dBV in Europe. Mic noise levels are
more like -120dBV or lower. That's quite a high signal to noise ratio
in cables often running together. That's why we use balanced lines and
I had a problem with connected shields at the end of 100metre stereo
cables when the connected shells touched and caused a "ground loop"
Either don't ground the shells (clip off the tag) or keep them
insulated from each other and the ground. My other problem was shells
touching a mic stand which
was on damp earth which caused fizzle.
I also had a problem with my long outdoor cables because all my mixer
and recorder power supplies were "floating". I measured 12V between
the mixer ground and the company ground. In the UK all our supply
sockets have a ground connection, and I used one socket as my master
ground and all my hums disappeared.
> Can my recorder be broken even if using XLR connectors works fine in
> the same channels?
No, but the XLR inputs may not be fully balanced. If the mics are
"floating" with a two wire connection this is not usually a problem,
but it any part of the circuit is also unbalanced you may be partially
grounding part of the circuit by dipping it in water.
All digital recorders give off digital hash and this is what you may
be hearing. The simple answer is to use the connection that gives less
North Devon, UK
Cogito cogito ergo cogito sum - Ambrose Bierce
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