B&K 4007DDS sweep generator

Yes. That is what a sweep function generator does.

You should be able to sweep the whole range if you wish.

I just looked at where I bought my Regal function generator recently, and it seems it's no longer made. To bad, because its a nice one that got replaced by a 40/25 Mhz version. How ever, these have arbitrary functions in them that allows you to design your own wave forms and has USB host for drive stick etc.

I paid $450 for mine. It would of been a much better deal if they still had some.

The replacement units now cost under $1k.

Thanks! I see sweep functi>

DDS technology is a synthesis of the frequency, little is done as for as, RC type of circuits being switch in/out over the range. Your range seems to be minor in demand.

This is digitally done, so there is not reason why it can't be done. I've never tried that with mine because I don't need that wide of a sweep how ever, I know that I can put in any start and any end I want , up to the limits of the unit, which 20 mhz.

I needed a frequency generator that had sub Hz resolution. We bought this cheap one from protek and I really like it. The manual also stinks.

George H.

For anyone that doesn't need to go outside the sound card audio range, the signal generator in Daqarta uses your sound card and provides resolution of 1/65536 Hz (0.000015 Hz). It's totally free. (Daqarta's 30-session/30-day trial period applies to using the inputs... the outputs from the generator continue to work forever.)

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Relevant and useful spam, thanks!

Hmm that's not spam then... bacon?

Bob, I mean to drop you an email also.

George H. (gherold_at_teacshspin.com)

Called B&K and asked a few questions about the 4007DDS. The fellow actually had one working nearby apparently and we went through its paces over the phone. I recall him mumbling something about the resolution of the frequency control but paid it no mind and went ahead and ordered one....Big mistake!!!

All the range buttons do is move the decimal point up and down which would be okay provided frequency control had a coarse option. Instead, frequency control seems to be via some multiturn rotary optical device which is good from a "no pot wear perspective" but it takes like 10 revs of the control knob just to change the frequency from say 1KHz to

5KHz. Now I understand what the fellow was saying about resolution....It's too darn fine!!!

But it doesn't end there...You lose the last frequency and decimal setting when you turn off the device because it's all digital without any memory. Also, the waveform selection switches are momentary so you cannot "lock" the waveform. Long story short....You are returned to a sinusoidal 1KHz frequency every time you switch on the device. The workaround for that seems to be to leave it on....What a POS!!!

Finally, I'm yet to figure out how to have the frequency displayed during sweeps. Maybe this is normal for sweep generators. Whatever, I'm returning it even if it entails a restocking fee.

What I really want now is a programmable ramp generator and connect it to the VCG input of my function generator. That way I can sweep up and hold at the high end or sweep up then down continuously. Sweeping up then starting over from the low end was never really a preference anyway. Tried using low frequency 4007DDS triangle output as a RG but have to keep adjusting the offset every time output level is adjusted....A PITA.

You need something like this.

I have a slightly older version that isn't as high in freq but does basically the same. These units have USB storage options and so on how ever, you'll pay some money.

P.S. That unit you got should of at least been able to retain it's last set up from power cycle. That's a bad idea in equipment like that..

Also, normally you have a function to adjust the freq in digit segment places. I don't understand why that one does not allow it.

If you want lab grade, you have to pay for it. Look for a good used HP 3325B.

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In YOUR opnion only.

Simple. It wasn't designed to.

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You're so enthusiastic, its just making me jump up and down in joy!.

They aren't very expensive just now.

Cheers

Phil Hobbs

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Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058
hobbs at electrooptical dot net
http://electrooptical.net

Well, a run-of-the-mill non-digital function generator (or sweep function generator) can address all the mentioned issues including a

1:100 frequency range provided the VCG (aka VCF, VCO) input is used. The somewhat out of the ordinary sweep features can be incorporated easily using a MCU based ramp generator. We're talking less than $5.00 worth of components and the programming is a piece of cake. However, if per chance there's a suitable ramp generator out there for less than $100.00 then I'll bite out of laziness.

Neither want nor need lab grade stuff based >

Good. Now find an open manhole cover...

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You can\'t have a sense of humor, if you have no sense!

I miss having one on my bench, but everything is out of my budget until some modifications are completed to make my home more handicapped accessible. I may never get another chance to do the work. I am installing a used aluminum ramp and installing an outside door to my bedroom. Then I have to borrow a cement mixer to widen the 18" wide sidewalks so I can use a walker or cane without going off the edges. The used electric power chair I'm rebuilding is too wide for the existing walkway, as well.

I'll just have to use my TS-382F for now. My HP 331 Distortion Analyzer was damaged when the shop roof leaked. It ruined the meter movement and washed all the numbers off the scales. :(

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You can\'t have a sense of humor, if you have no sense!

"Restocking fee" is really their profit; so they get to make that profit when they re-sell it... ..tell them you did NOT agree to a re-stocking fee and that you demand a full refund under the UCC which says you can do that if the item is not fit for the purpose for which it was made.

Only snag is you don't get the full frequency range on all waveforms.

The phase noise is unbelievably low for a synth FG. I had a a hard time telling the difference between my 3325b and my 8640B at 20MHz.It is characterized as a "Synthesizer / Function Generator" rather than a "Synthesized Function Generator", apparently a significant distinction.

I've got a Rohde & Schwartz AFGU that does all waveforms to max frequency. However the phase noise is cruel compared to the HP.

--
"Electricity is of two kinds, positive and negative. The difference
is, I presume, that one comes a little more expensive, but is more
durable; the other is a cheaper thing, but the moths get into it."
                                             (Stephen Leacock)

I was using it below 20 MHz. Sometimes to 1/100 hz to measure the intigration time of the AGC system in high end telemetry receivers.

The 3325A or B were the cleanes waveform generators in the company. We had about 50. Only three were of the HP 3325 family. Two in engineering, and the one on my bench. It was supposed to be theirs, but after they stole my Tektronix 2246, I got the 2246B that was on order, and their third 3325B :)

I still have some Rohde & Schwarz equipment in my home shop, but it never impresed me as well designed, or all that good. OTOH, I had to take it to get the used HP equipment I wanted. :(

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You can\'t have a sense of humor, if you have no sense!