[TenTec] O2 output level with PSK aux in

Jim M. jmiller1706 at cfl.rr.com
Tue Feb 10 23:19:27 EST 2009

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

----- 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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