Signal Generator: Which one to buy ? What to look for in a signal generator ? - Page 4

HP8903B · 11th January 2012, 08:13 PM

Just to make sure I understand right.

The computer option has very low distortion, much lower than the function generator.
Is this true only in sine wave ?

The function generator generates square waves much better than the computer option.

HP8903B · 11th January 2012, 08:42 PM

Hollowstage,

Could you tell me more about the Leader models that you mentioned.
Seems like the Leader LAG-120B is comparable to the HP 209A.

veteran · 11th January 2012, 08:52 PM

Quote:

Originally Posted by manp111

Just to make sure I understand right.

The computer option has very low distortion, much lower than the function generator.
Is this true only in sine wave ?

The function generator generates square waves much better than the computer option.

You're right. This is the 5kHz square wave generated by my sound card

HP8903B · 11th January 2012, 08:58 PM

haha, that's not square at all.

HP8903B · 11th January 2012, 09:28 PM

What do you guys think of this Leader LAG-120B on ebay:
LEADER LAG-120B AUDIO GENERATOR | eBay

What are some potential problems with this unit and how likely ?

theoldtrout · 11th January 2012, 09:30 PM

I've been using a Radford LDO4 [and others] for years. Low distortion, good square wave and an oscillator stop facility.

nigelwright7557 · 11th January 2012, 09:32 PM

I picked one up cheap on ebay.
Has worked well for 5 years now.

Salas · 11th January 2012, 09:42 PM

Quote:

Originally Posted by manp111

haha, that's not square at all.

Ringing (not that much as in #33) is inherent in digital synthesis. The DDS instrumentation ones do filter the ringing but they lack in rise time as you push them higher to their limit VS analogue ones due to LPF. Talking under 500$. Full rise time is still available on their TTL output which is not filtered and you will be able to see the inherent ringing. Very good stability in PPM over the years and great functionality is the other side of the coin. Very good signal quality is offered by TTI-Thandar made in UK in medium to low prices (relatively, as generators go), they do good analogue still.
If using soundcard FFT for THD which is great for that, there are many cheap enough good solutions for nicely shaped square waves up to 1MHz from instruments that go to 3 or 5MHz. Their THD won't be better than -50dB though.

HP8903B · 11th January 2012, 09:45 PM

Quote:

I picked one up cheap on ebay.
Has worked well for 5 years now.

You mean the Leader LAG-120B ?

HollowState · 11th January 2012, 10:05 PM

Quote:

Originally Posted by manp111

Hollowstage,

Could you tell me more about the Leader models that you mentioned.
Seems like the Leader LAG-120B is comparable to the HP 209A.

Leader is OK, Made in Japan, but is probably the best if the Asian imports. I've never owned one, but I have had some of their other stuff.

11th January 2012, 09:32 PM	#37
nigelwright7557 diyAudio Member Join Date: Apr 2008 Location: Carlisle, England	I picked one up cheap on ebay. Has worked well for 5 years now. __________________ http://www.murtonpikesystems.co.uk PCBCAD50 pcb design software.

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
spdif signal generator	Nikon1975	Digital Source	3	23rd August 2010 02:18 AM
Signal Generator Help	Bengali	Equipment & Tools	12	24th April 2008 04:20 PM
looking for a signal generator	Ahmad_tbp	Solid State	21	8th September 2006 11:37 PM
DIY signal generator?	Loial	Parts	13	19th September 2005 10:36 AM
signal generator help	hizz_eye	Solid State	2	3rd March 2005 10:25 AM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

11th January 2012, 08:13 PM	#31
HP8903B diyAudio Member Join Date: Jun 2010 Location: Texas	Just to make sure I understand right. The computer option has very low distortion, much lower than the function generator. Is this true only in sine wave ? The function generator generates square waves much better than the computer option.

11th January 2012, 08:42 PM	#32
HP8903B diyAudio Member Join Date: Jun 2010 Location: Texas	Hollowstage, Could you tell me more about the Leader models that you mentioned. Seems like the Leader LAG-120B is comparable to the HP 209A.

11th January 2012, 08:58 PM	#34
HP8903B diyAudio Member Join Date: Jun 2010 Location: Texas	haha, that's not square at all.

11th January 2012, 09:28 PM	#35
HP8903B diyAudio Member Join Date: Jun 2010 Location: Texas	What do you guys think of this Leader LAG-120B on ebay: LEADER LAG-120B AUDIO GENERATOR \| eBay What are some potential problems with this unit and how likely ?

11th January 2012, 09:30 PM	#36
theoldtrout diyAudio Member Join Date: Aug 2008	I've been using a Radford LDO4 [and others] for years. Low distortion, good square wave and an oscillator stop facility.