Looking for a DDS module 10kHz-1MHz, 2Vrms sine into 50ohms

tml

you'd need a buffer but you said you didn't mind a bit of hacking

-Lasse

Several kinds of outputs, 50 ohm, ttl, etc. Even has a knob and comes with power, too. But since it is Hong Kong, I'd write and make sure they know it's going to 60Hz, 110VAC so they provide the RIGHT part with it.

Jon

Ah. Crap. Looks like the SAME unit!!

hehe. Sorry, Jörg.

Jon

Not sure if it fits your needs (no display) but on Ebay there are lots of cheap AD9850 or AD9851 based modules starting at less than $5. Source code for programming can be easily found around the net.

Then I might a well just buy the bare chip, it's cheaper :-)

That seems to be the very same module as in my link. It comes under all sorts of part numbers and names.

What I (so far) have not found is any useful documentation about these boards.

Yes, those can be bought everywhere. But no LCD, no output buffer amp, bare bones. Those are almost like buying the bare chip. I am looking for something I can screw into a tester and have some local control as well.

Worst case I'll have to order a module like in my link and reverse engineer it so I can arrive at a hack that makes it work in our tester.

is

xy

but then you'll need a pcb, xtal regulator, etc. and have to build it with this you just need a buffer amp. You don't have something laying around with ~3-4x gain that can drive 50R?

-Lasse

though:

Oh, I can build it, just a simple amp. But another board to be roached in. If it has to be that way then so be it. I'd also have to build an LCD module, plus some sort of encoder for local control.

le

...

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boxy

I see, if you don't have anything to control it with then it is a bit more work than just a buffer

how about something like this:

open source hard and software, even comes with a programmer if you want to do you own software

-Lasse

though:

Thanks! That looks like a very good candidate. Not sure why it needs 4W of power but I can supply that. The display looks like the one on my Nokia phone so should have a backlight. If not we'll just supply flashlights :-)

I don't like that open coil switcher inductor, makes for lots of EMI. But this my home turf so I can deal with that.

though:

Someone demo'ed it on Youtube:

Looks nice. The frequency dialing is weird through. CCW makes it go up, maybe the programmer is also designing faucets :-)

I guess since the firmware is open one can correct for oddities like that.

A bit concerning is the frequency instability mentioned here but that may have to do with the switch mode converter on there:

Instability is a showstopper for me but hopefully it's just a minor screw-up that can be corrected.

Q: What did Joerg say to his girlfriend at the restaurant teble when they went out together to dine on the Valentine's?

A: "What would you like to order, my sweet dear little fattie?"

Regards, Mikko

There are some DDS modules that are popular for amateur radio work; you may want to search around using terms like "QRP" and "transmitter" or "QRP" and "local oscillator".

I know there's at least one QRP transmitter that uses a DDS as its oscillator; that should give you 1 to 5 watts out, with perhaps a need to modify an output filter to get down to the lower frequency you want.

I looked in that market and most of the DDS are quite deeply embedded in a transceiver or receiver. Like this:

I have even seen a DDS synthesizer in a tube amplifier somewhere.

The filter usually doesn't have to be adjusted in a DDS unless the master clock or something like that is changed.

Of course, in Finland sausage is considered a vegetable. ;)

Cheers

Phil Hobbs

Yep. The leading brand is HK Blue.

But it is damn good when roasted on a stick like marshmallows in the big West.

Have you ever tried Johnsonville Brats? (Bratwurst). Roasted over a wood fire, outdoors, yumm. I could eat 3-4 in a row but of course that's not healthy so I restrict myself to one.

Nothing better than standing around the fire with a beer in hand, discussing politics, cars and football :-)