LCD replacement display for old spectrum analyzer : anyone interested ?

[Robert Lacoste]

Hi guys,

I've developed for my own use a small LCD display to replace the analog
display found on old spectrum analyzers. Basically it is a X/Y digital
plotter, connected on the external X and Y outputs of the analyzer, and
plotting the curve on a 320x240 pixel display, with selectable modes
(sample/max peak/min-max peak) and a hardcopy RS232 port. I just published
this design in the last edition of the Circuit Cellar magazine (september
03), and got a couple of emails from guys wanting to buy or build it.
Unfortunatly the Epson display I used is no longer available (crazy LCD
business...), and some improvements will be needed on the design to use it
in anything else than my own equipment.

So the question : Do you think there is a significant market for such a
product ? Perhaps proposed as a kit, or even a partial kit
(PCB+display+programmer microcontroller) ? Would you be personnaly
interested ?

If I get enough answers then I will seriously work on it ;+) !

Yours,

 

[Charles Schuler]

Hi guys,

I've developed for my own use a small LCD display to replace the analog
display found on old spectrum analyzers. Basically it is a X/Y digital
plotter, connected on the external X and Y outputs of the analyzer, and
plotting the curve on a 320x240 pixel display, with selectable modes
(sample/max peak/min-max peak) and a hardcopy RS232 port. I just published
this design in the last edition of the Circuit Cellar magazine (september
03), and got a couple of emails from guys wanting to buy or build it.
Unfortunatly the Epson display I used is no longer available (crazy LCD
business...), and some improvements will be needed on the design to use it
in anything else than my own equipment.

So the question : Do you think there is a significant market for such a
product ? Perhaps proposed as a kit, or even a partial kit
(PCB+display+programmer microcontroller) ? Would you be personnaly
interested ?

What is your estimate regarding the cost of such a kit? Do you plan to
offer the same resolution (320 x 240)? How flexible will it be ... lend
itself to almost any X/Y application? I suppose color is out of the
question?

 

[Jack Smith]

Display cost is around $100, kit (PCB+display+microprocessor only) should be
in the $250 range


Yes, seems enough...


Every X/Y application where the X varies slowly enough (down to 50ms per X/Y
scan)


Yes...

Thanks for your inputs...

Interesting project. I, like many other hobby-types have several
pieces of CRT-based HP gear--8754A network analyzer, 8558B spectrum
analyzer, 8557B spectrum analyzer to identify three--that have the XY
recorder output you identify.

Although the LCD panel would be an interesting addition, and I can see
that it would be a lot cheaper than finding a new CRT, it would
interest me a lot more if it had some provision for outputting the
data.

You already have to do some sort of A/D to get the XY info, and I
assume you would also look at the pen lift output to synch the trace.
Suppose you also outputted the (X,Y) pairs via a RS232 port. Shouldn't
add much to either the hardware of software and would be handy to
have.

Not in the realm of easy, of course, would be the ability to write a
TIFF or JPG file or print the result from the LCD module. But, if it
can be gotten into the computer through the RS-232, those tasks can be
accomplished without complicating the LCD panel.

And, of course, this function could be done without the LCD; all you
really need is a PIC with a 3-input ADC. But if you are going to the
trouble to build the graphic module, why not tack on the RS232 data
dump as well? And besides, I don't know when I will have enough time
to get around to the PIC solution.

Jack

 

[Robert Lacoste]

Thanks for these inputs, I effectively have an RS232 dump port, I just need
to develop the PC side software to convert the bitstream to a bitmap file...

Cheers,