[TenTec] O2 output level with PSK aux in

[Ron Castro]

Jim:

I would look at the Navigator to see if there is an internal adjustment or 
perhaps a software adjustment.  There is nothing wrong with driving the O2 
direct from a soundcard, which is what I did for a long time.  The only 
changes have been to add some external audio processing equipment, but I 
have always been able to match the level needed by the Aux input.  Receive 
audio direct into the soundcard works fine, too.  In either case, you need 
to make sure there are no ground loops or you'll get hum.

My first inclination about the power problem would be to verify that the 
external meter is correct and that you're looking into a reasonably good 
load.  If all of that is correct, there could be a calibration problem with 
the meter, which can be adjusted internally.  There are a couple of pots 
that adjust the power, forward reading the meter calibration, but check with 
the factory before you do any tweaking!

         Ron Castro
 Chief Technical Officer
    Results Radio, LLC
               N6IE
      www.N6IE.com

----- Original Message ----- 
From: "Jim M." <jmiller1706 at cfl.rr.com>
To: "'Ron Castro'" <ronc at sonic.net>; "'Discussion of Ten-Tec Equipment'" 
<tentec at contesting.com>
Sent: Tuesday, February 10, 2009 8:19 PM
Subject: RE: [TenTec] O2 output level with PSK aux in


> Let me clarify one thing I didn't mention.  I am using the "Navigator" USB
> sound card interface box, which works quite nicely otherwise.  The O2 spec
> says it needs -6 dBm audio to the aux connector to drive it to full 
> output.
> When I drive the O2 directly from the computer sound card set to about 
> half
> level, I can get enough audio to bring the O2 up to full output on the
> external wattmeter.  That happens at about 0.5 volt P-P audio from the
> computer sound card, which is probably somewhere in the right area(a 
> guess).
> But... when I use the Navigator sound card (USB external), I can't get
> enough audio drive to the O2 even with all its level controls on max.  And 
> I
> have the O2 Aux gain menu setting at max.  With the Navigator I get about
> half full power.  All I can think is that the Navigator sound card doesn't
> output enough audio for the Orion Aux input.
>
> So maybe I need to return the Navigator, and drive the O2 from the 
> computer
> sound card directly, or maybe its an internal setting on the Navigator.  I
> have used Navigator setup to set all attenuators to zero, so I can't
> understand why it has output that is lower than what the O2 needs.  Does 
> any
> one else use the Navigator with the Orion on data modes?
>
> Now a separate issue is the possible discrepancy between the external
> wattmeter and the O2 wattmeter (that's not a Navigator issue).  When the
> external meter reads 100W, the O2 meter is at the max peg.  If I crank the
> audio down to where the O2 meter reads just below 100, then I am only
> getting 50-70 watts actual RF out (using a continuous audio drive signal).
> The O2 power meter also seems to bounce around a lot.
> Thanks, Jim N4BE
>
> -----Original Message-----
> From: tentec-bounces at contesting.com [mailto:tentec-bounces at contesting.com]
> On Behalf Of Ron Castro
> Sent: Tuesday, February 10, 2009 10:42 PM
> To: jmiller1706 at cfl.rr.com; Discussion of Ten-Tec Equipment
> Subject: Re: [TenTec] O2 output level with PSK aux in
>
> It sounds like there is not enough output from the computer to drive the 
> O2.
>
> Check to see if the ALC light is flashing.  If everything is turned up on
> the computer and you're not getting ALC indication, then you need more
> output from the computer.  There are generally two level adjustments on 
> the
> computer that need to be turned up: one is the "Wave" level, the other is
> the "Master" level.  If one of those is down low, you'll get low output.
> Also check for bad connectors and cables.
>
> The SP will increase the output power, although I can't understand why the
> discrepancy between the O2 Wattmeter and the external one.  When the
> external meter reads 100 Watts, what does the meter in the O2 do?  Are you
> loading into a good load?  If there really is that much of a discrepancy,
> you may need to do a master reset.
>
>         Ron  N6IE
>      www.N6IE.com
>
> ----- Original Message ----- 
> From: "Jim M." <jmiller1706 at cfl.rr.com>
> To: "Discussion of Ten-Tec Equipment" <tentec at contesting.com>
> Sent: Tuesday, February 10, 2009 6:54 PM
> Subject: [TenTec] O2 output level with PSK aux in
>
>
>> Using HRD sound card into rear panel auxiliary input.  With speech proc
>> off I get only about 50 watts out with max audio drive measured on rf
>> wattmeter.  The O2 meter shows 100 watts, not 50.  If I turn SP on, I can
>> get closer to 100 watts out.  The O2 power meter appears to be reading 2x
>> what is actually being transmitted?  And or the drive level without the 
>> SP
>
>> is cut 50 percent?  What's going on in the DSP?  Any suggestions on how 
>> to
>
>> get an honest 100 watts on Psk? Jim N4BE
>>
>> Jim
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>
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