[TenTec] RFI and Behringer MX-602a

[tlogan7 at cox.net]

Hi Ken -
I suspect that's what is happening, but last time I started playing with
with chokes for RFI it drove me crazy - suppose that's why I'm not reall
motivated to go on the "Choke Chase" heh heh.  Thanks Ken!!
73/Tim
----- Original Message -----
From: "Ken Kinyon - W7TS" <w7ts at attbi.com>
To: <tentec at contesting.com>
Sent: Sunday, March 02, 2003 10:18 PM
Subject: RE: [TenTec] RFI and Behringer MX-602a


> Hi Tim,
> It sounds to me like rf is being picked up by the mixer and getting into
the
> OMNI-VI through the speaker lead.
> Have you checked you CW sig on another receiver? If it sounds bad, I bet
> that is what is happening.
> I would ground the mixer to your station ground, and use some filtering of
> the speaker lead at the OMNI.  Perhaps start with several turns around a
> Toroid.  I got RF into my OMNI-VI+ via the RS-232 cable,  It took an old
> fashioned solenoid rf choke in both wires to stop it.
> Regards and good luck,
> Ken W7TS
>
> -------------------
> Kenneth E.  Kinyon
> 34 Princeton Circle
> Longmont, CO 80503-2106
> Voice: (303) 684-0037
> Fax:  (303) 776-5088
> E-mail: W7TS at attbi.com
>   W7TS at qsl.net
>   W7TS at arrl.net
> ALPCA #8339
> ARRL-LM
> -------------------
>
> -----Original Message-----
> From: tentec-bounces at contesting.com
> [mailto:tentec-bounces at contesting.com]On Behalf Of tlogan7 at cox.net
> Sent: Sunday, March 02, 2003 21:57
> To: tentec at contesting.com
> Subject: Re: [TenTec] RFI and Behringer MX-602a
>
>
> Bob -
> I think I mislead you. My external speaker is connected to the HEADphones
> jack - thus it does not need an amplifier and gives excellent volume and
> ability to control via the mixer. The Omni's external speaker jack is fed
to
> a channel input. It works very well except that transmitting cw is
> unacceptably distorted. I have not tried Tx with SSB. Hope that sounds
more
> logical!
> 73/Tim
> ----- Original Message -----
> From: "Robert & Linda McGraw K4TAX" <RMcGraw at blomand.net>
> To: <tentec at contesting.com>
> Sent: Sunday, March 02, 2003 8:56 PM
> Subject: Re: [TenTec] RFI and Behringer MX-602a
>
>
> > Tim:
> >
> > If I read this correct, you are taking a speaker level signal into a
> > microphone level input.  Chances are that you are driving the input into
> > distortion, pre any gain control or level control stage on the mixer.
> > Secondly, the phone output level of a mixer is only slightly above line
> > level and is designed to drive a much higher Z than a speaker.  Also, it
> is
> > most likely rated at a few milliwatts of power where a speaker needs an
> amp
> > of 2 or 3 watts (2000 to 3000 milliwatts) to be clean.
> >
> > I doubt that you have an RFI problem.
> >
> > I suggest that you place some 20 to 40 dB loss attenuation between the
> > speaker out of the radio to the input of the mixer.  A simple 5 to 10 K
> pot
> > will do the trick and allow you to make adjustments to suit yourself.
> > However, to drive a speaker from the phone output of the mixer, you'll
> need
> > to put a audio amp capable of some 5 or more watts between the mixer and
> the
> > speaker.  This most likely will address your concerns.
> >
> > 73
> > Bob, K4TAX
> >
> >
> >
> > ----- Original Message -----
> > From: <tlogan7 at cox.net>
> > To: "tentec reflector" <tentec at contesting.com>
> > Sent: Sunday, March 02, 2003 12:29 PM
> > Subject: [TenTec] RFI and Behringer MX-602a
> >
> >
> > > Hi folks -
> > >   Been fooling around abit with the above mixer. Seems pretty great
for
> > > receive but sure distorts/ruins cw sending. I'm assuming the terrible
> > sound
> > > of my cw sig is from RFI - in which case I probably won't spend much
> time
> > > trying to fix it.  Any adjustments to gain and other settings does not
> > cure
> > > it.
> > >   I run the speaker into the phone input and am using channel 1 from
the
> > > mixer to the rigs speaker out - no amp or anything. Any suggestions
> other
> > > than normal RFI cures or is there something about setting the mixer
that
> I
> > > may be missing? If it's RFI the mixer goes - not worth the effort to
me
> > > since I'm not real heavy into the audio manipulation part  - in case
> > anybody
> > > wants to buy a mixer.
> > > Thanks folks.
> > > 73/Tim NZ7C
> > >
> > > _______________________________________________
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> > >
> >
> >
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