Forums

Where do you buy instruments, and who makes 'em?

Started by Tim Wescott December 1, 2011
I need to get a nice audio signal generator.  Something that refers back 
to a crystal, instead of a function generator chip.  Preferably something 
with a DDS and a nice high-accuracy DAC.

I have something hacked together on proto board that worked astonishingly 
well, all things considered -- but it's still hacked together on 
protoboard, and only changes frequency with a change of a crystal.  
Yesterday I hooked the power up backward, and now it doesn't generate a 
steady frequency at all.

So I'd like to get something with a knob and a case and all that neato 
stuff, and if it happens to have a USB port and can be talked to with a 
PC running Linux that'd be a minor but nice addition.  If possible I'd 
like to spend less than $250, but I have no clue what the state of the 
market is, so I don't know if $250 is reasonable.

So -- when you want to get on the internet and order stuff like this, 
where do you go?  Newark, Mouser and DigiKey all have stuff, but they 
primarily sell components.  Tucker has stuff, but I've heard comments 
that it's expensive.  So if you have a place that you like, that doesn't 
cost an arm and a leg?

And -- who makes good inexpensive instruments these days?  My Beckman 
Industrial signal generator is a cheap thing that makes a wiggly line on 
an oscilloscope, and has been doing so reliably since the day I bought it 
over 20 years ago.  I have no complaints about build quality or how long 
it's lasted -- just how well it has always done its job.

-- 
My liberal friends think I'm a conservative kook.
My conservative friends think I'm a liberal kook.
Why am I not happy that they have found common ground?

Tim Wescott, Communications, Control, Circuits & Software
http://www.wescottdesign.com
On Thu, 01 Dec 2011 09:30:48 -0600, Tim Wescott <tim@seemywebsite.com>
wrote:

>I need to get a nice audio signal generator. Something that refers back >to a crystal, instead of a function generator chip. Preferably something >with a DDS and a nice high-accuracy DAC. > >I have something hacked together on proto board that worked astonishingly >well, all things considered -- but it's still hacked together on >protoboard, and only changes frequency with a change of a crystal. >Yesterday I hooked the power up backward, and now it doesn't generate a >steady frequency at all. > >So I'd like to get something with a knob and a case and all that neato >stuff, and if it happens to have a USB port and can be talked to with a >PC running Linux that'd be a minor but nice addition. If possible I'd >like to spend less than $250, but I have no clue what the state of the >market is, so I don't know if $250 is reasonable. > >So -- when you want to get on the internet and order stuff like this, >where do you go?
I usually start with Tequipment.NET (yes, that's their real DBA name, legacy of the dot-com era I guess) over at http://www.tequipment.net. Never had a problem with them and they've got a pretty wide and deep selection of equipment as well as repair parts. Need a replacement pump crank for a Hakko 808 solder sucker? They've got it. Good prices, good selection. -- Rich Webb Norfolk, VA
Took a while to wait for a usable one at a decent price (sleazebay), but 
I'm happy with my HP3325A (you'll need a GPIB interface to have a 
computer talk to it, though - but I'm not doing that at present.) Covers 
the audio band and above and below for quite a nice distance, in that 
old-fashioned red LED style. Internal crystal reference, ovenized 
internal is possible (depends on options), and external reference is 
also an option if you have a better reference. No knob, though. I tend 
to figure used working old HP is probably more reliable than new Chinese 
junque, often for similar money.

YMMV.

-- 
Cats, coffee, chocolate...vices to live by
Please don't feed the trolls. Killfile and ignore them so they will go away.
Tim Wescott <tim@seemywebsite.com> wrote:
> I need to get a nice audio signal generator. Something that refers back > to a crystal, instead of a function generator chip. Preferably something > with a DDS and a nice high-accuracy DAC. > > I have something hacked together on proto board that worked astonishingly > well, all things considered -- but it's still hacked together on > protoboard, and only changes frequency with a change of a crystal. > Yesterday I hooked the power up backward, and now it doesn't generate a > steady frequency at all. > > So I'd like to get something with a knob and a case and all that neato > stuff, and if it happens to have a USB port and can be talked to with a > PC running Linux that'd be a minor but nice addition. If possible I'd > like to spend less than $250, but I have no clue what the state of the > market is, so I don't know if $250 is reasonable. > > So -- when you want to get on the internet and order stuff like this, > where do you go? Newark, Mouser and DigiKey all have stuff, but they > primarily sell components. Tucker has stuff, but I've heard comments > that it's expensive. So if you have a place that you like, that doesn't > cost an arm and a leg?
tucker is ok, if you call them you can negotiate prices as well. If something is a dud they'll take it back unlike assholes off ebay or those lab junk liquidation places.
On Thu, 01 Dec 2011 11:57:44 -0500, Ecnerwal wrote:

> Took a while to wait for a usable one at a decent price (sleazebay), but > I'm happy with my HP3325A (you'll need a GPIB interface to have a > computer talk to it, though - but I'm not doing that at present.) Covers > the audio band and above and below for quite a nice distance, in that > old-fashioned red LED style. Internal crystal reference, ovenized > internal is possible (depends on options), and external reference is > also an option if you have a better reference. No knob, though. I tend > to figure used working old HP is probably more reliable than new Chinese > junque, often for similar money.
That's a good point. I tend to either buy used "name" stuff (like Tek or HP), or Chinese stuff with a US label -- because if you care, you _can_ harass the Chinese into making decent stuff. Of course, my Agilent 54622D came straight from Agilent, and it's probably the best buy that I've ever made. My only beef with it is that the logic analyzer section is really just 16 1-bit scope channels. But I started using that when I started this business, and it comes in handy every time I have a mixed signal board on my bench. -- My liberal friends think I'm a conservative kook. My conservative friends think I'm a liberal kook. Why am I not happy that they have found common ground? Tim Wescott, Communications, Control, Circuits & Software http://www.wescottdesign.com
Tim Wescott wrote:
> > I need to get a nice audio signal generator. Something that refers back > to a crystal, instead of a function generator chip. Preferably something > with a DDS and a nice high-accuracy DAC. > > I have something hacked together on proto board that worked astonishingly > well, all things considered -- but it's still hacked together on > protoboard, and only changes frequency with a change of a crystal. > Yesterday I hooked the power up backward, and now it doesn't generate a > steady frequency at all. > > So I'd like to get something with a knob and a case and all that neato > stuff, and if it happens to have a USB port and can be talked to with a > PC running Linux that'd be a minor but nice addition. If possible I'd > like to spend less than $250, but I have no clue what the state of the > market is, so I don't know if $250 is reasonable. > > So -- when you want to get on the internet and order stuff like this, > where do you go? Newark, Mouser and DigiKey all have stuff, but they > primarily sell components. Tucker has stuff, but I've heard comments > that it's expensive. So if you have a place that you like, that doesn't > cost an arm and a leg? > > And -- who makes good inexpensive instruments these days? My Beckman > Industrial signal generator is a cheap thing that makes a wiggly line on > an oscilloscope, and has been doing so reliably since the day I bought it > over 20 years ago. I have no complaints about build quality or how long > it's lasted -- just how well it has always done its job.
<http://www.ebay.com/itm/2MHz-DDS-Signal-Generator-Source-60MHz-Frequency-Counter-DDS-Module-P-A-/150709330213> Uncased, but is less than $40 US. -- You can't have a sense of humor, if you have no sense.
On Thu, 01 Dec 2011 09:30:48 -0600, Tim Wescott wrote:

> I need to get a nice audio signal generator. Something that refers back > to a crystal, instead of a function generator chip. Preferably > something with a DDS and a nice high-accuracy DAC.
On the bay I see plenty of cheap (less than $25) AD9851 based DDS generator cards intended to be hooked to a microcontroller (which could talk to a USB host). Here are schematics and code examples. <http://www.yourportablelab.com/downloads/schematics/AD9850_1V4.pdf> <http://www.yourportablelab.com/downloads/AD9850_1_V3_C.rar> This is a partially diy solution, but can be easily put into a box. Similar ready made products cost a lot more. I have no idea of the quality of the generated signal though.
Tim Wescott <tim@seemywebsite.com> wrote:

>And -- who makes good inexpensive instruments these days? My Beckman
Just look on Ebay. Chinese make tons of inexpensive instruments these days. -- Failure does not prove something is impossible, failure simply indicates you are not using the right tools... nico@nctdevpuntnl (punt=.) --------------------------------------------------------------
On 12/01/2011 10:30 AM, Tim Wescott wrote:
> I need to get a nice audio signal generator. Something that refers back > to a crystal, instead of a function generator chip. Preferably something > with a DDS and a nice high-accuracy DAC. > > I have something hacked together on proto board that worked astonishingly > well, all things considered -- but it's still hacked together on > protoboard, and only changes frequency with a change of a crystal. > Yesterday I hooked the power up backward, and now it doesn't generate a > steady frequency at all. > > So I'd like to get something with a knob and a case and all that neato > stuff, and if it happens to have a USB port and can be talked to with a > PC running Linux that'd be a minor but nice addition. If possible I'd > like to spend less than $250, but I have no clue what the state of the > market is, so I don't know if $250 is reasonable. > > So -- when you want to get on the internet and order stuff like this, > where do you go? Newark, Mouser and DigiKey all have stuff, but they > primarily sell components. Tucker has stuff, but I've heard comments > that it's expensive. So if you have a place that you like, that doesn't > cost an arm and a leg? > > And -- who makes good inexpensive instruments these days? My Beckman > Industrial signal generator is a cheap thing that makes a wiggly line on > an oscilloscope, and has been doing so reliably since the day I bought it > over 20 years ago. I have no complaints about build quality or how long > it's lasted -- just how well it has always done its job. >
HP 3325A. I just paid $223 plus $31 shipping for one on eBay. Plus it goes up to 30 MHz. Cheers Phil Hobbs -- Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC Optics, Electro-optics, Photonics, Analog Electronics 160 North State Road #203 Briarcliff Manor NY 10510 845-480-2058 hobbs at electrooptical dot net http://electrooptical.net
On Dec 1, 10:30=A0am, Tim Wescott <t...@seemywebsite.com> wrote:
> I need to get a nice audio signal generator. =A0Something that refers bac=
k
> to a crystal, instead of a function generator chip. =A0Preferably somethi=
ng
> with a DDS and a nice high-accuracy DAC. > > I have something hacked together on proto board that worked astonishingly > well, all things considered -- but it's still hacked together on > protoboard, and only changes frequency with a change of a crystal. > Yesterday I hooked the power up backward, and now it doesn't generate a > steady frequency at all. > > So I'd like to get something with a knob and a case and all that neato > stuff, and if it happens to have a USB port and can be talked to with a > PC running Linux that'd be a minor but nice addition. =A0If possible I'd > like to spend less than $250, but I have no clue what the state of the > market is, so I don't know if $250 is reasonable. > > So -- when you want to get on the internet and order stuff like this, > where do you go? =A0Newark, Mouser and DigiKey all have stuff, but they > primarily sell components. =A0Tucker has stuff, but I've heard comments > that it's expensive. =A0So if you have a place that you like, that doesn'=
t
> cost an arm and a leg? > > And -- who makes good inexpensive instruments these days? =A0My Beckman > Industrial signal generator is a cheap thing that makes a wiggly line on > an oscilloscope, and has been doing so reliably since the day I bought it > over 20 years ago. =A0I have no complaints about build quality or how lon=
g
> it's lasted -- just how well it has always done its job. > > -- > My liberal friends think I'm a conservative kook. > My conservative friends think I'm a liberal kook. > Why am I not happy that they have found common ground? > > Tim Wescott, Communications, Control, Circuits & Softwarehttp://www.wesco=
ttdesign.com We've got a GWinstek SFG2104 and a Protek 8003FD. The GWinstek seems a bit more stable. But the protek has more functionality. Some stuff we buy direct, and other from Newark. George H.