--- In email@example.com
, "Terry" <wb4jfi@...> wrote:
> --- In firstname.lastname@example.org, "verduynj" <Jan.Verduyn@> wrote:
> > Bill, Tony, All,
> > I made my first CW contact this morning with the SR6 Exciter
> > prototype using the latest Version of PowerSDR Software which
> > released last Friday. Very pleased with this!!
> > http://www.tracey.org/wjt/sdr1k/SoftRock40/PowerSDR-KD5TFD-srxmit-
> > 20060928.zip - thanks Bill!!
> > I worked ON5CBK, Patrick at 11:15 UTC on 7015 Khz and received
> > report .. Not bad for 0.6 Watt RF output!!
> > Second contact was a solid 15 minute QSO with Joe, DM0K and
> > a 559 report.
> > Is this the first CW contact with the Softrock Exciter or has
> > else beaten me to it?
> > Some additional info from us who prototyped to Exciter:
> > - Using (Dell on board Sigmatel STAC 92xx)s unwanted sideband
> > carrier suppression is at more -30dB down from full rated output
> > shown on a spectrum analyser. -30dB is the FCC requirement I
> > understand.
> > - With this particular soundcard it is advisable to stay away
> > the maximum sampling rate; otherwise output power and sideband
> > suppression start to suffer. For example sampling freq 48K, I
> > need to limit TX within 22 Khz range 7034 KHz - 7088 KHz. With
> > sampling rate I can cover 7014 KHz - 7096 KHz
> > - Before putting the exciter you should do a sanity check by
> > monitoring your transmission on a separate receiver.
> > Connect the SR6 Exciter to a Dummyload.
> > a) Tune the RX to the Transmit Frequency and position the RX
> > lead near the Dummy load until you obtain an S9+10dB Smeter
> > b) Insert a 30dB attenuator in the antenna lead and note the new
> > Meter reading.
> > c) Now tune to Carrier Frequency (7056 KHz) and check whether the
> > Meter reading is same or less as in step b)
> > d) Tune to the unwanted sideband freq (7056 KHz +/- TX freq and
> > whether S-Meter reading is same or less as in step b.
> > - Recent correspondence "Big signal at 0 Hz" on the reflector:
> > confirm that Exciter Carrier Suppression depends significantly on
> > amount of 1/f noise which a particular soundcard produces. I plan
> > tailor the I and Q response of the Exciter so it starts to drop
> > 200Hz and see what difference this makes. Results will be updated
> > Tony.
> > best 73s
> > Jan
> > G0BBL - M0PUB - G8BTR (QRP2K Design team)
> Congrats Jan!! My exciter just came to life, I can get the
> to do an ID, then send constant dots and dashes. I am not familiar
> with PowerSDR, having used Rocky for SDR experiments up to now.
> I am hoping to be one of the first to have a SoftRock-to-SoftRock
> (assuming I can figure out PowerSDR). Anybody else interested?
> My unit draws about 250ma in transmit, and puts out around 1/2
> Still playing with it, I should be on the air later today (Sunday).
Sorry for the add-on reply, but has anyone looked at the exciter/amp
on a spectrum analyzer? I used my homemade analyzer (Wes Hayward
W7ZOI unit), and found the 2nd harmonic on 20 meters was only about
12db down. I am looking at construction for errors. I assume its
not the audio phasing (I/Q), as that would create an image within the
40 meter band. I will feed a 20 meter signal into the board, and see
if the receiver hears it strong, an indication the input filter is
messed up. Then, I guess I will sweep the filter on the amplifier
Is my assumption about the audio phasing correct?