Don Yea!!! Thanks for the information! I have
Tony – KB9YIG awaiting a word to go ahead with 15 pin connector board
kits to interface directly to the Delta 44 with 1/8 inch stereo cables or
jacks. without external box etc. I have a mass of wires running all over the
place with infernal ¼ inch connectors, and in the long term plans that just
ain’t gonna cut it. ¼ inch is fine for guitars which don’t go on DXpeditions,
but there is a limit to 1930’s audio connectors! I know you are making a different point
here, however, would love it if you would consent to a drawing of the
components you mention. Any ideas for filtering and isolation would also be
appreciated. I think many folks will go the Delta 44 / 66? Route. For anyone who is reading, Tony is also
specing out a serial port to paddle circuit board with 1/8” stereo
connection for CW which I’ll produce and ‘market’. Thanks Eric From: Hello all, I was considering using a DB 15 connector,
appropriate plugs and shielded cable to interface between the SDR and the Delta
44, bypassing the breakout box altogether. I thought this would make a
little cleaner setup here (not that this has mattered much before,
hi). I traced out the wiring inside the box to find out the pinouts for
the various ins and outs, and will list them below. One interesting thing that I found was how M-Audio
implements Balanced or Unbalanced configurations. As you may know, they
allow balanced audio ins and outs by using both the Tip and Ring, with the
shield tied to the sleeve, But it appears that they are not using a
true Balanced input at the sound card. The Ring connection simply terms.
into a 10k resistor in series with a 22u cap to common, while the Tip continues
on to the sound card input. The outputs are sim., the Ring is tied to
common through a 130 ohm R and series 22u cap, while the Tip carries
the actual output. I suppose these components match the Z
values on tip and ring as they appear to external equipment, but there is no
signal present or used by the Ring half of the line. In the past, there was some talk of using balanced
I/Q signal paths between the SDR and Sound card, to gain noise cancelation
and s/n improvment at the sound card. This is a step up from our current
unbalanced method. Seems like M-Audio is defeating any
advantage of using balanced lines, even if a new SDR incorporated them. I
wonder if the Delta 44 is typical of other higher end
"Pro" sound cards? Just something you might want to keep in the
back of your mind for future use. Anyway, here are the breakout box pinouts: TRS
Jack DB15 pin In 1 tip..............13 In 1 ring.............term'd (Input ring terminations
are 10k in series with 22uF to sleeve) In 1 Sleeve........14 In 2 tip..............6 In 2 ring............term'd In 2 sleeve........14 (Input 1 and 2 sleeves are tied
together) In 3 tip..............15 In 3 ring............term'd In 3 sleeve........7 In 4 tip..............8 In 4 ring............term'd In 4 sleeve........7 (Input 3 and 4 sleeves are tied
together) Out 1 tip..........1 Out 1 ring.........term'd (Output ring terminations
are 130ohms in series with 22uF to sleeve) Out 1 sleeve.....9 Out 2 tip..........2 Out 2 ring.........term'd Out 2 sleeve.....9 (Outs 1 and 2 sleeves are tied
together) Out 3 tip..........3 Out 3 ring........term'd Out 3 sleeve....11 Out 4 tip..........4 Out 4 ring........term'd Out 4 sleeve....11 (Outs 3 and 4 sleeves are
tied together) Pins 5, 10 and 12 are not used. Pins 14, 7, 9, and 11 (sleeves) are grounded at the sound
card's ground plane 73 and gn Don, wd4egf |
- [Flexradio] Delta 44 Breakout Box and Balanced audi... Don Newberry
- Re: [Flexradio] Delta 44 Breakout Box and Bala... ecellison
- Re: [Flexradio] Delta 44 Breakout Box and Bala... Jim Lux
- Re: [Flexradio] Delta 44 Breakout Box and Bala... Bill Guyger
- Re: [Flexradio] Delta 44 Breakout Box and Bala... Bill Guyger
- Re: [Flexradio] Delta 44 Breakout Box and Bala... Don Newberry
- Re: [Flexradio] Delta 44 Breakout Box and Bala... ecellison
- Re: [Flexradio] Delta 44 Breakout Box and Bala... Mike Naruta
- Re: [Flexradio] Delta 44 Breakout Box and ... Simon Brown \(HB9DRV\)
- Re: [Flexradio] Delta 44 Breakout Box and ... Philip Covington