Re: [TenTec] Orion 2 Headphone RFI Filter

["pfizenmayer" <pfizenmayer2@q.com>]

I received my OII 11/15/06 and the headphone filter was still not installed 
at factory - SN 07C10266. But no matter what , I agree with Ron - get the 
board - they have designed it so it just a matter of unplugging and 
replugging a cable and putting in a couple screws . Each side is an 
identical two section cascaded low pass PI network - all surface mount - two 
series inductors and 3 shunt capacitors. Inductors are marked 4R7 (DCR 1 
ohm) and 471J (DCR 22.9 ohms) - can't tell you what the chip caps are - no 
markings.This was a filter board received on 4/7/2007.It completely 
eliminated any trace of RF on headphone leads - which was a big problem at a 
KW on 10 meters with beam about 45 feet above the Orion.
73 de Hank K7HP


----- Original Message ----- 
From: "Ron Castro" <ronc@sonic.net>
To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
Sent: Friday, May 01, 2009 5:25 PM
Subject: Re: [TenTec] Orion 2 Headphone RFI Filter


> Give a call to Ten Tec support.  I think you can get the board for free 
> and
> install it yourself.  It's actually very simple and requires no soldering,
> cutting, etc.
>
> BTW...My O2 came from that same production run, which I believe was the
> first one.
>
>           Ron  N6IE
>       www.N6IE.com
>
> ----- Original Message ----- 
> From: "Fred Mott" <fredmott@zoominternet.net>
> To: "'Discussion of Ten-Tec Equipment'" <tentec@contesting.com>
> Sent: Friday, May 01, 2009 7:41 PM
> Subject: Re: [TenTec] Orion 2 Headphone RFI Filter
>
>
> > Where can I find documentation on the Orion II Headphone RFI Filter?  My
> > rig
> > was shipped on 12/13/05 and received 12/15/05.  I have made no
> > modifications, only firmware updates. MY O2 needs this modification. 
> > Fred,
> > AB8AH
> >
> >
> > -----Original Message-----
> > From: tentec-bounces@contesting.com 
> > [mailto:tentec-bounces@contesting.com]
> > On Behalf Of pfizenmayer
> > Sent: Friday, May 01, 2009 12:36 PM
> > To: Discussion of Ten-Tec Equipment
> > Subject: Re: [TenTec] Orion 2 Headphone RFI Filter
> >
> > I do not have time right now to dig out the schematic and see if this
> > would
> > allow an external check - but I can tell you the filter adds 24 ohms DCR
> > in
> > each side of the headphone output.   If you want to do the exercise -
> > measure open circuit voltage of the sidetone - then load with 32 ohms or
> > so
> > and measure the voltage again - You can calculate source impedance . Do
> > this
> >
> > on both and you will tell if it has the filter . A no filter will be at
> > least 24 ohms lower output impedance.
> >
> > I think I have that data - but will not have time until this evening to
> > dig
> > it out or remeasure.
> >
> > 73 de Hank K7HP
> >
> > ----- Original Message ----- 
> > From: "Dick Williams" <k8ztt@mho.com>
> > To: "Discussion of Ten-Tec Equipment" <tentec@contesting.com>
> > Sent: Friday, May 01, 2009 7:47 AM
> > Subject: Re: [TenTec] Orion 2 Headphone RFI Filter
> >
> >
> > > Doug,
> > >
> > > I am not sure when the started;  but if you don't receive a satisfactory
> > > answer on here, since you installed one in your radio, it might be
> > > easiest
> > > to take a quick look inside your friends radio.  That way you can verify
> > > for
> > > sure if one is (or is not) installed.
> > >
> > > Dick K8ZTT
> > >
> > >
> > > ----- Original Message ----- 
> > > From: "Doug Turnbull" <turnbull@net1.ie>
> > > To: <tentec@contesting.com>
> > > Sent: Friday, May 01, 2009 7:48 AM
> > > Subject: [TenTec] Orion 2 Headphone RFI Filter
> > >
> > >
> > > > I have a friend who is purchasing an Orion 2 from another EI ham this
> > > > week.
> > > > Can anyone tell me at what serial number TT first introduced the
> > > > headphones
> > > > RFI filter?   I installed one in my radio eighteen months or two years
> > > > ago.
> > > > I do not know the exact age of this radio but want to insure that EI2JD
> > > > is
> > > > fully sorted.    73 Doug EI2CN
> > > >
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