[TenTec] O2 output level with PSK aux in

Dr. Gerald N. Johnson geraldj at storm.weather.net
Wed Feb 11 05:17:20 EST 2009

On Wed, 2009-02-11 at 01:29 -0500, Jim M. wrote:
> You are right, when I set the drive audio until the ALC just stops flashing
> on the O2 then I get about 30-40 watts out, or in that range, which is what
> has been recommended by others. That's where I leave it for PSK (maybe PSK
> was a bad example to use).... 

Yup a bad example.

> So what about RTTY (AFSK)?. I would like to
> get 90-100W out on that mode, since it is not as sensitive to intermod I
> would imagine.

Not as sensitive and not as readily checked.

>  But again, the drive from the Navigator won't drive it fully
> to 100W on RTTY.  The external wattmeter is a Nye Viking dual meter peak and
> average reading type RFM-003.  They don't make it now but it is accurate:
> http://www.eham.net/reviews/detail/2466  SWR is 1.03/1.  
> I still would like to hear others' experience with the Navigator (or other
> USB interfaces) driving the O2 Aux input, RTTY AFSK as an example.  Are you
> getting sufficient audio drive?  Thanks to all for the comments.

With line input to the radio, the radio isn't nearly so sensitive to
ground loop problems so only cables SHOULD be enough interface. I have
no trouble with my FT-857D and an internal sound card on PSK or RTTY.
Perhaps the typical OS level controls aren't affecting the USB sound
card and it needs its own software to set those levels. That can be a
problem. I'm running puppy Linux for digital modes and I don't know if
even detects a second sound card or USB sound card. I haven't tried
digital modes with windoze and probably won't since I don't have my
shack computer set to boot windoze. It does dual boot MS-DOS and Linux
Fedora Core 3 from the hard drive and puppy Linux from a CD. But runs
MS-DOS for packet most of the time.

> Jim N4BE
73, Jerry, K0CQ

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