I wasn't asserting that this means it distorts or "saturates", but merely reciting the rating given on the data sheet. I agree that it should be perfectly adequate for interfacing with normal computer sound card inputs as long as one didn't set the line out level too high. It's fine here.
Bob NW8L On Wed, Aug 6, 2008 at 7:30 PM, Tom W8JI <[EMAIL PROTECTED]> wrote: >> It's a 600 ohm transformer, rated for 7dBm max (about 1.7 Vrms across 600 >> ohms). >> >> Bob NW8L > > But that doesn't mean it distorts or "saturates". It is simply a rating. > > My K3 for example on a good Agilent selective level meter starts to distort > at -5dB reference to 1 milliwatt into 600 ohms. That's a front panel setting > of about 50 on the line output level adjustment. At -5dB the second > harmonic is down 58 dB (absolute level of -63 dB mW ). At lower settings it > gets better. > > While I have not looked inside the radio (and won't bother) the distortion > has all the characteristics of a mismatched output device because it clips > at about the same level regardless of frequency. If it was that commonly > spoke of but elusive to find "core saturation" the point of distortion > should change with frequency. That's because the flux level should change > with frequency for a constant voltage across the primary as the reactance > changes with frequency. > > When I reduce line output setting to 25 (whatever that means) the distortion > is too close to noise floor to measure accurately. > > I would think -10dB below 1 mW, while a bit low from commercial standards, > is good enough for any properly adjusted ham radio sound card or audio > system. I'm pretty fussy about things that matter, and I think the audio > distortion shortfall (at least from what measure) is greatly over rated. It > isn't out of line with anything else I use, and is a lot better than some > things I won't use. > > This is a sample of one unit, but it looks good to me when the level is kept > about -10 dB 1 mW into 600 ohms. I can't see a problem in a single tone > harmonic distortion test. > > 73 Tom > _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
