Bob Cunnings wrote: > > Does the advice for setting up soundcard digital modes given here: > > http://www.mail-archive.com/elecraft@mailman.qth.net/msg53656.html > > become effective when using this new version? Specifically: > > "If you try and trick the system and run with *zero* ALC bars in > PSK31, the ALC has to work hard to give you your requested power - or > maybe it will think there is insufficient signal to work with - and > your Tx S/N may suffer. So, *please* set it to 4 bars in soundcard > "digital" modes." > > This sounds right given the description of the ALC changes. > > Bob NW8L > I am observing that it is impossible to get the requested power output in DATA A. If I set the PWR control of the K3/10 to 5W then no amount of audio input will get the external power meter to read 5W output on a pure audio tone. Instead the meter reads about 2.5W at the same LINE IN setting that gave 5W out when the power was increased to max. Slowly increasing the audio drive above this level with the K3 meter showing ALC shows the ALC pulsing about twice a second. The amount of ALC shown during the pulses increases as the drive level increases. The power meter (moving coil, average reading) will only go up to about 3.0W and some slight pulsing of the meter needle is also evident corresponding to the K3 ALC display.
Sending a PSK idle tone instead of a pure tuning tone the meter shows a level a bit below half the level on the tuning tone, commensurate with the K3 limiting the output to 2.5 or 3W PEP despite 5W being requested. The only way to get a real 5W peak is to set the PWR control to 12W and then regulate the power entirely using the audio drive, which is not a very accurate or foolproof way of doing it. In PSK D mode where the audio is generated internally by the K2 the power does seem to be correctly regulated by the power control (the K3 does not generate the short "tail" of pure carrier at the end of the transmission like most sound card programs do.) However something is definitely not right with the power level setting. If I transmit in DATA A, then select PSK D and send something, I only get about 0.2W! I have to change mode to CW and then back to SSB and then the power out in PSK D is correct. Unlike someone else who reported low output on SSB my own "aaallo" testing has found nothing amiss in this mode. ----- Julian, G4ILO K3 s/n: 222 K2 s/n: 392 G4ILO's Shack: www.g4ilo.com Zerobeat Ham Forums: www.zerobeat.net/smf -- View this message in context: http://www.nabble.com/K3-FIRMWARE-UPDATE%3A---MCU-1.87%2C-DSP-1.69---%28Finally%21%29-tp17041394p17045737.html Sent from the Elecraft mailing list archive at Nabble.com. _______________________________________________ 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
