> On Nov 9, 2007, at 1:20 PM, (deleted) wrote:
> > Recently the connect/disconnect messages on my node are at a very low
> > level. You can barely hear them on the repeater.
> > The wierd part is that once connected, all the audio is ok. THis
> > system is regularly used on nets and the audio to and from from
> > participants on the linked reflectors is good.
> > I haven't had a chance to check things with a service montor yet,
> > maybe this weekend.
> > It seems any wav files played are low.
> First, if ALL wav files, including connect and disconnect messages are
> playing "too low", this typically means that you've set your audio
> levels incorrectly. Stop and read the instructions below, or see the
> link at the bottom for other methods documented by Randy KC6HUR, which
> also work relatively well.
> Log into the node while it's not connected anywhere (as the repeater
> username) and type:
> This file is the reference audio for IRLP, and should be played from
> your node and your node radio measured for deviation at that time.
> The deviation should be set from 3.0 to 3.5 kHz for the portion of the
> audiotest wav file that is 1000 Hz tone. Dave's voice should be
> peaking at or slightly above 5 kHz of deviation when measured on a
> fast-responding deviation meter, and assuming your radio is not
> hitting it's built-in limiter at 5 kHz (or worse, if the deviation
> limiter is set below 5 kHz).
> Next, you should attach a service monitor or other calibrated FM
> signal source that can generate a 1000 Hz tone at 3.5 kHz deviation to
> your node's receiver, and then connect to the echo reflector:
> decode 9990 [add your prefix if your node uses one]
> Remember, now that you've already set the node's output deviation
> level -- don't touch it after the audiotest setting above.
> Transmit your tone and then unkey. When the Echo Reflector echos back
> the audio, use the instrument to measure what your node is
> transmitting and note the returned deviation. If it's coming out of
> your radio lower than 3.5 kHz, turn up the INPUT audio going INTO the
> sound card. If it's above 3.5 kHz deviation, turn down the INPUT level.
> INPUT level is the level your sound card is recording your signal at,
> and then digitizing it and sending it to the all-digital echo
> reflector. The reflector is sending you back the exact same bits
> you're sending out.
> So if the on-air deviation is different, the thing that needs
> adjusting at this point is what you are sending (your receiver audio).
> After you get it to send back whatever deviation you're sending in --
> unhook the signal generator, and you're done. Leave it alone.
> From then on, if someone sounds too light or too hot, IT'S THEIR
> MISCALIBRATED NODE and not your problem.
> Audio levels are all over the place from IRLP nodes. If you're
> wanting a good "sanity check" test after you set your node correctly,
> find someone here on the list who has properly done their node using
> the above method, and test with them. Don't trust anything you get
> from a node unless you know they followed the above procedure.
> If you don't have access to proper test gear for FM work, Randy KC6HUR
> has documented two other methods to get a calibration job on your node
> done "as right as possible". See his website and look for the three
> methods in the pillar/bar on the right hand side of the screen:
> Besides the "Using a Service Monitor" method, he has also documented
> the "Poor Man's Method" and the "Bessel-Null Method".
> Okay as a final note, you should be VERY close after the above
> exercise, but if you're finding that things are a "bit hot" or a "bit
> low" (it shouldn't be off by much), absolutely leave the INPUT alone
> now (you've calibrated it as best as you can, and you can test with
> someone with a similarly-calibrated node and they can tell you how you
> sound -- if you want to make absolutely sure) and only move the OUTPUT
> audio slider in aumix.
> Randy's documentation of how to do it correctly with the three
> different methods he describes are better information than this e-mail
> or likely anything else you'll get on the list, here.
> It's what one of my Elmer's would say: "Are you a thinkin' man, or
> are you a knowin' man?" Do you THINK your node audio is done right,
> or did you measure it scientifically and KNOW your audio is done
> right...? The latter, is -- of course -- always preferred.
> Nate Duehr, WY0X