[TenTec] adding xtal filter to the Orion

[Ron Castro]

It still sounds to me based on your original comments that the noise you are
hearing is actually originating in the PA of the other radio, not as a
result of lack of selectivity or front-end overload of the Orion.  A really
good transmitter may have residual broad band noise of -120 dBc which is
generated by the output transistors even when there is no RF (transmit mode,
but key up), but some radios have considerably less, as little as - 80dBc.
This would amplified by the amplifier, and added to it by virtue of its own
secondary emission noise.  Once generated, it contaminates the site and you
can't filter it out.  The added selectivity would be needed on the
transmitter, not the receiver.

As far as breaking the tmp cable from the A0 board to the A3 board, it's
easy to do, and I did it to add a 3 dB splitter so I could connect an
outboard Perseus SDR receiver to the main antenna to run CW Skimmer and
other spectrum analyzer functions.

             Ron Castro
                  N6IE   
         www.N6IE.com
              Member:
         REDXA   NCCC
         NCDXF   ARRL



-----Original Message-----
From: tentec-bounces at contesting.com [mailto:tentec-bounces at contesting.com]
On Behalf Of Rick Dougherty NQ4I
Sent: Tuesday, February 28, 2012 4:34 AM
To: ronc at sonic.net; Discussion of Ten-Tec Equipment
Subject: Re: [TenTec] adding xtal filter to the Orion

Hi All...a number of you have no clue waht I am talking about...first each
station I have has a transmit (100 watt) bandpass filter that helps to
reduce out of band noise created by one rig on another band ...then there is
a 80 db bandpass filter after the amp (very high power bandpass
filter)....so there is something on the order of 130 db rejection of OUT of
band interference.To further reduce INBAND would require a Crystal filter
(read low power no transmit thru) or some other very high Q very narrow
filter thast only has 5-10 khz of operating bandwidth...no such device is
sold currently on the ham market....at one time Sherwood engineering would
custom make a xtal filter that is installed in a trancsevicer that has in
and out rcvr terminals on the back of the radio... in WRTC comp[etition in
Brazil a few years ago 4O3A introduced a switchable xtal filter device that
would switch xtals in 5 khz increments...allowing him to transmit and rcv
within 5 khz of the run radio effectively...I am attempting to get my rcvrs
so that we too can hear close to the run stationand at a lower level than we
currently do. Currently my station has antenna separation that is over 500
ft apart from run station to mult station...I am working at extending that
number so that INBAND interference will go down by the square of the
distance...this will improve INBAND interference also...I have enough OUTof
BNAD rejection from the combination of BAndpass filters...so to implement
what I need will require a modification to the Orions in my station to allow
the insertion of a xtal filter in the rcvr path....

de Rick NQ4I


On Mon, Feb 27, 2012 at 5:37 PM, Ron Castro <ronc at sonic.net> wrote:
> We set up something like that every FD using an Orion II.  We found that
the OII was perfectly clean and we could operate on the same band at the
other transceiver with no interference FROM the OII, but the ICom blew S-5
wide-band noise that I could see on a spectrum analyzer.  You can't get that
out once it's generated.
>
> Those bandpass filters multi multi's use won't work either since they
cover the whole band.
>
> Our solution was to set up the antennas side-to-side about 200' apart and
use a Mark V at the other station.  Worked perfect!
>
>             Ron Castro
>                  N6IE
>         www.N6IE.com
>              Member:
>         REDXA   NCCC
>         NCDXF   ARRL
>
>
> -----Original Message-----
> From: tentec-bounces at contesting.com 
> [mailto:tentec-bounces at contesting.com] On Behalf Of Mike Bryce
> Sent: Monday, February 27, 2012 1:40 PM
> To: nq4i at contesting.com; Discussion of Ten-Tec Equipment
> Cc: Discussion of Ten-Tec Equipment
> Subject: Re: [TenTec] adding xtal filter to the Orion
>
> It would seem to me the simplest thing to do is to get one or two of the
band filters commonly used by multi-station contesters.
>
> Our radio club uses them for FD
>
> Off hand I don't know the exact technical name for them
>
> Mike wb8vge
>
> Sent from my iPhone
>
> On Feb 27, 2012, at 4:11 PM, nq4i at contesting.com wrote:
>
>> Hi Kim. It is a rcvr problem not transmitter. When 2 stations are on 
>> the same band there is an inherent noise generated in either rcvr 
>> that can be supressed. Currently the Orion transmitter is one of the 
>> cleanest transmitters on the market. My aim is to allow a second rcvr 
>> to hear at a lower level than the current s4 level. I am not a design 
>> engr but am relating what I know and what io hear. It maybe that to 
>> achieve that would require transmitter filtering. But some 
>> improvement can be had by addressing the rcvr.  Rick Sent on the 
>> Sprint® Now Network from my BlackBerry®
>>
>> -----
> _______________________________________________
> TenTec mailing list
> TenTec at contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec
>
> _______________________________________________
> TenTec mailing list
> TenTec at contesting.com
> http://lists.contesting.com/mailman/listinfo/tentec
_______________________________________________
TenTec mailing list
TenTec at contesting.com
http://lists.contesting.com/mailman/listinfo/tentec