Agreed. Self-contained in the unit itself is best as well.
You will need at least a set of two 10 bit converters for X and Y and a lesser resolution but similar speed converter for Z modulation. Jumpers for the different typical instrument voltage levels would be nice as well as pots for fine tuning of gain and offsets. Just some real basic analog stuff. Power should be a wide range input of say 6 to 24 volts, a LDO probably, and you may want it analog so as to not have to worry about noise.
If you think 100 kHz is sufficient then perhaps an AD7993 would be good, 2 uS and 4 input channels. LTC has a bunch of very high speed ADCs(10's of MHz), but, heck, so does everyone these days. You want unipolar or bipolar inputs for your analog front end of course. It will come down to price. If you get the right family you could even go 12 bit or more as options.
I would say to avoid the fancy features initially. Don't bite off too much, you can always release more features in firmware later on.
Peter
Let's see if this posts. I am getting frigging tired of the "Unable to deliver your message" Yahoo BS.
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--- In hp_agilent_equipment@..., "W2HX" <w2hx@...> wrote:
Personally, I like the no-PC approach. Don't have to worry about hard drives
failing, reinstalling long-obsolete operating systems, etc. I like a piece
of hardware (with embedded software)!
-----Original Message-----
From: hp_agilent_equipment@...
[mailto:hp_agilent_equipment@...] On Behalf Of Kuba Ober
Sent: Thursday, September 01, 2011 8:10 PM
To: hp_agilent_equipment@...
Subject: Re: [hp_agilent_equipment] X-Y to VGA/USB converter
There will be a frame buffer, that's not a problem, and a video DAC
as an option -- it's one chip these days, not expensive either.
PC is of course cheap, but you may not wish to use one -- this is meant
to interface an instrument to a stand-alone off-the-shelf dirt-cheap
monitor OR a PC.
Kuba
On Sep 1, 2011, at 6:24 PM, Peter Reilley wrote:
If you go with VGA, DVI, HDMI or any other pseudo video
interface they you must include a video frame buffer, video speed
D/A converters and the logic to support it. Even though LCD
screens include a memory cell at each pixel it is not useful to you
given those interfaces. They scan the video just like the old CRT
monitors.
You can't beat a PC for cheep high quality video.
What is the speed of the old Tek and HP X/Y monitors?
Pete.
----- Original Message -----
From: Kuba Ober
To: hp_agilent_equipment@...
Sent: Thursday, September 01, 2011 5:44 PM
Subject: Re: [hp_agilent_equipment] X-Y to VGA/USB converter
That's "almost" what we want, but not exactly. It has a fixed
800x600 resolution, and it will look like crap on widescreen
monitors. For some reason everyone must be watching movies on
their monitors, because non-widescreen aspect ratios are disappearing.
I've recently been to a local Microcenter and the best deals were only
to be had on widescreen units with ridiculous resolutions (say 1600x1000).
I'm thinking of something that would be $100 in parts for a basic version,
optimized for use with real instruments not some imaginary specs someone
thought up.
This means:
1. Input channels with ranges that allow 1:1 connection to a selection of
popular instruments (here I need *YOUR* help!).
2. Screen colorization options -- again, based on behavior of real
instruments.
3. Use with available and "future-proof" monitors -- that means
analog VGA would be one option (solder a DAC), DVI another (solder
LVDS drivers).
I think that for spectrum analyzers it'd be cool to have an option
of double IF inputs and on-board frequency counting to generate
an accurate X position and on-screen display/cursors. Again: I need
input from *YOU* as all I have is a Tek 7L14 SA plugin. I would need
to know what are the output levels, frequency ranges, etc. on IF outputs
from various SAs.
Obviously the board would have room for various options (VGA output,
DVI output, USB output, IF input, etc) and they'd be populated as needed.
So a basic version may have USB interface and three 12 bit input channels
with
10MHz bandwidth, and nothing else.
Since it smells like an FPGA-based solution, it's not unthinkable to have
an optional high-resolution (16 bits at 50+ MSps) channel to take video
output
from SA's and do level measurement and filtering or even swept FFT. This
would come
at a small incremental hardware cost, but obviously would be very useful.
Cheers, Kuba
On Sep 1, 2011, at 4:12 PM, W2HX wrote:
Check out vectorVGA Tempest
$179. However, some scaling input will be needed. I inquired to this
company
about using this for my 8566/68 specans. They have a product called the
VectorVGA PRO which is $2000 and will do what we want out of the box.
However, that's a lot of coin! I sent the XYZ specifications of my
specan
to them for comment on the applicability of the "tempest" version (which
has
nothing to do with electronic eavesdropping) and this is their
response....
[Non-text portions of this message have been removed]
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