OK. Here is the deal. The Delta 44 card, which is where the audio is directly input for voice operation does not have a mic preamp. The old Firebox and the FA66 do have preamps. When you connect a mic to the front panel of the SDR-1000 it is a pass through to channel 3 of the Delta44 input.
When I was using that card with my SDR-1000, I had to connect a W2IHY EQplus (or the 8-band EQ) to get adequate output gain to drive the radio to full power. You can try changing the level on Input 3 from -10dBV to +4 dBU and see if that makes any difference. In the M Audio mixer, you want to see signal for this channel in the -10 to -12 range I suspect this is your issue since CW and PSK via VAC does not interface with the Delta44 card in the same way the mic does with a line in port for the mic and you get full power out using the standard PA calibration procedure. What you may need is a little pre-amplification for the mic. Do not use the software mic boost. As you noted before if not properly used can add a lot of distortion. One other side comment. The Delta44, although it says it has balanced inputs, does not. It converts them to unbalanced on the card. For a point of reference, I upgraded to the FA66 and used the true balanced microphone input with a balanced mic (like the ProLine (PR20) mic from Heil) and never had any issues with mic gain. - Tim ________________________________________ From: George [EMAIL PROTECTED] Sent: Sunday, May 04, 2008 5:25 PM To: Tim Ellison Cc: [EMAIL PROTECTED]; [email protected] Subject: RE: [Flexradio] Microphone drive and auto-tuner settings in PowerSDR Hi Tim, Thank you for the reply. Any help getting this crazy transmit audio issue addressed is appreciated. Currently the sound card is the recommended M-Audio Delta 44 that came with the radio. All cables are the ones that come with the radio from Flex. The computer is a Compaq 2.5Ghz running XP Pro. My wattage rating is from observing the PowerSDR meter and also an MFJ tuner with power meter which I'll admit is not the highest build quality. But it does seem to track with the software meter. It does have a "peak" function. I wish I could see 10-20 watts on SSB after running the calibration routine! :> George N7BUI -- Tim Ellison <[EMAIL PROTECTED]> wrote: George, The mic gain for an SDR-1000 is totally dependent on the sound card used. Can you elaborate in more detail what card is used and how it is connected? Also how are you determining the wattage transmitted? Adjusting the PA gain as described below will result in a signal that is probably not very clean. Just a comment about SSB and wattage. When running SSB modes, you will not see 100 watts unless you have a true peak reading watt meter (some that claim they are aren't) If you do not have a "true" peak reading watt meter, you will only see RF output in the 10-20 watt range. - Tim ________________________________________ From: [EMAIL PROTECTED] [EMAIL PROTECTED] On Behalf Of George [EMAIL PROTECTED] Sent: Sunday, May 04, 2008 3:59 PM To: [email protected] Subject: [Flexradio] Microphone drive and auto-tuner settings in PowerSDR Probably one of the most frustrating things about the SDR-1000 is getting the transmit audio up to a decent output power level. When the calibration routine is used the digital modes and CW are just fine at near 100 watts into a dummy load. But transmit audio is always at a 1-5 watt levels. Which I'll admit it sounds very good at these levels. Cranking up the mic audio beyond about "40" results in poor sounding audio. Turning on "mic boost" is about worthless as it just generates lots of white background noise when transmitting even with the mic unplugged! My solution (and probably several others) is to adjust the PA settings to the point where mic settings below "40" result in a more normal 40-75 watts output. But this also throws off all other settings as they obviously reference to the PA calibration settings. Especially the built-in auto-tuner settings. It seems to be programmed to stay at 15 watts no matter what the actual power output is. Of course if the PA settings are tweaked, the auto-tuner doesn't follow suit and when tune is selected as much as 70 watts can be dumped through the tuner. Which I'm sure isn't doing it any good. Is there any way of adjusting the auto-tuner settings? I'm almost ready to yank it out of the radio and go back to using an external tuner as it's settings are adjustable in setup. My current microphone is an MH-31 which is from my FT-847. It is actually the best sounding mic I've used on this rig. I've tried all sorts of mics including amplified mics, computer mics, and major amateur brand desk mics. None seem to have the drive levels that this radio requires. Am I stuck with purchasing an external mixer? I have searched the knowledge base and aside from recommending purchasing Heil microphone cartridges, I haven't found much in the way of discussion of levels required by this rig. George N7BUI _______________________________________________ FlexRadio Systems Mailing List [email protected] http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kb.flex-radio.com/ Homepage: http://www.flex-radio.com/ _______________________________________________ FlexRadio Systems Mailing List [email protected] http://mail.flex-radio.biz/mailman/listinfo/flexradio_flex-radio.biz Archives: http://www.mail-archive.com/flexradio%40flex-radio.biz/ Knowledge Base: http://kb.flex-radio.com/ Homepage: http://www.flex-radio.com/
