Robert,
It is not the KX2/KX3 that decides which channel from the soundcard is
used, but the PC application software. In general the left channel is
used for digital work, but some can reverse it.
So it is best to buffer the PHONES output and send it off to a separate
jack.
73,
Don W3FPR
On 4/16/2018 12:48 AM, Robert Morris wrote:
Hi Don,
Thanks for your feedback. I'm hoping one volume knob will do the job
for everyone else too. Plus, if the KX3 puts out enough signal for the
PC, then you don't really want an amplifier in the signal path.
I want to be sure about the channel which needs to go to the sound
card. Are you saying the left channel from the KX3 is the one the
computer needs, or are you saying the computer needs the signal to be
present on the left channel of its input? If it's the latter, then
that is already how the SPX3 is wired.
For the first prototype, the stereo output of the KX3 goes into the
SPX3 input port, then is split. The left channel goes to the
amplifier, and the right goes to the left channel of the output port.
Will that do the job, or does the computer really need the signal
which originated from the left channel of the KX3? I don't see in the
KX3 manual where it specifies which channel the digital mode signal is
output. I had assumed it would be on both left and right channels.
Thanks and 73,
Robert (AG6ZZ)
On 2018-04-15 21:24, Don Wilhelm wrote:
Robert,
You will need to provide a means of connecting the KX2/KX3 PHONES
output to a soundcard for the use of digital modes.
The KXSPA should connect to the left channel since that is the
channel that is normally used by soundcard digital.
I think that means you would want to provide a knob controlled gain
control on your active speaker so the sound level to the speakers can
be controlled without disturbing the level to the soundcard being
used for digital modes.
73,
Don W3FPR
On 4/15/2018 11:40 PM, Robert Morris wrote:
First of all, I want to say thanks to everyone for all the great
feedback I've been getting on the speaker. Here's are some requested
features:
1. One stereo channel to speaker driver and another channel to
output jack (already in first prototype)
2. 12V input (planned is 9-15V, like the KX3)
3. Separate powered (active) and unpowered (passive) speakers
The reasons I've gotten for this is that it would save on the weight
of and inconvenience of charging a second battery
4. Separate volume controls for the internal speaker driver and the
output jack
The reason I've gotten for this is that a computer will need the
volume set separately from the speaker.
Some have stated the computer's software can adjust the gain on the
input, and that there only needs to be one volume control for the
speaker driver. I'll need consensus on this from the digital mode folks.
5. USB power output
This would be convenient for those who wish to use their speakers as
phone chargers.
Things to consider:
A. Making two different speakers substantially increases
manufacturing costs for the most expensive part; the enclosure.
Since most folks will be fine with just one speaker, then the lower
production numbers of the passive speaker would make its per unit
cost much higher than the active one. However, folks would expect a
lower price on the passive one. So, I'd have to sell them as pairs
to justify manufacturing the passive ones, which would mean a higher
cost to consumers who only want the active one. It would also
increase the cost to those who want both because of the two
different enclosures instead of just one enclosure twice.
B. The one issue which would force making both an active and a
passive speaker is the need stated by some respondents that the
active one would require a second volume control for the output to
the computer for digital modes. It would be expensive and time
consuming for me to try every digital mode software on every
operating system, so I need confirmation whether this is truly
necessary.
C. If a second volume control is not truly necessary, then that
simplifies things tremendously. I'll wait for consensus on this
before going into why.
D. A USB power output port is beyond the scope of the speaker's
intended utility. Also, it would draw down the battery at the cost
of significantly limiting how long the speaker could be used before
needing a recharge. Furthermore, the extra hole and port would
increase the cost while reducing ingress protection. Lastly, there's
not much room in the small enclosure to accomodate nonessential items.
Thanks and 73,
Robert (AG6ZZ)
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