Sorry, this is long. Maybe you folks can help with our project, point us to
sources of RF help, or at least help me find a scope. But because this is a
scope forum I'll start with the scope part. I should add that a DSO would be
nice, but an old fashioned CRT analog scope may be perfectly fine.
We
need a scope to examine a waveform that we want to apply to a pair of
electro-chemical cells wired in series. Currently we power the cells with 1.0
VDC, and they normally they draw between 3 and 5 A. It is thought that cell
performance would improve if we can cause the chemicals in the cells to
resonate, hence the desire to superimpose an AC signal on top of the DC. We
have been able to explore frequencies up to 100 kHz for square waves and
pulses and 300 kHz for sine waves, but not surprisingly those lowish
frequencies did not help.
We now want to explore frequencies from
about 1 MHz to as much as we can afford on a shoestring budget, but no less
than 30 MHz for square waves and pulses and 50 MHz for sine waves. 100 MHz
would be nice, but there's that budget issue.
The waveforms, at least
initially, would be limited to 1 V maximum, and never going negative. We are
thinking that the maximum AC amplitude would be 0.5 V peak, or 1.0 V peak to
peak, and that would be superimposed on a 0.5 V DC bias voltage. A minimum AC
amplitude would be 0.05 V peak, or 0.10 V peak to peak, and that would be
superimposed on a 0.95 DC bias voltage.
We'd also like to monitor
current if we can find a shunt that does not distort the waveform.
An
issue is that I can't guarantee that the final wiring will give us a common
ground point so we may need a scope and lead set up where can can measure two
differential voltages. (Our Tek 222 with it's isolated inputs is nice in that
regard, but at 10 MHz bandwidth won't work for these higher
frequencies.)
So if you guys can point us in the right direction for
what models of new or used scopes might work for us. Or even sell us one of
your surplus working scopes.
Local Craiglist scopes available that
appear to work from pics and description: (I know, buyer beware.)
Tek
2465 (not A or B) $350 firm. (Seems a little high)
Tek 2215A, $100 firm
(Not quite enough bandwidth)
Tek TDS 3052B (No price given, and I don't
know much about this other than labeled 500 MHz)
Anritsu MS2711D (I know
nothing about this brand or model)
We're also going to need an
arbitrary waveform generator, and the "superimposed RF on top of DC" power
supply. These could be the subject of another posting if there's any interest,
or we could keep those non scope subjects off forum.
If it makes any
difference, our 3 person start up is in Seaford, Delaware.
