Products > Test Equipment
Hantek HDG2002B AWG: 5Mhz or 100MHz? Let's see!
Cyber7:
@marabut: Good News! I have qty 5 LMX5080M coming from China in 3 weeks. $12USD shipped :-+
You can order from WWW.UTSOURCE.NET ...hopefully, this broker sells real, non-remarked parts....
Thanks for the pics. Interesting that VRegs U1 & U15 are missing, but they left the Vo filter caps behind :o weird.
Tinhead is right..through-holes for the OCXO source are unpopulated. Must be a TXCO under the shield cap. OCXO's may have greater stability (ppb), but don't you have to then wait for the entire unit to reach temperature equilibrium before trusting the OCXO output...
Also, an OCXO source would require a temperature stable reference voltage. Likely the missing U16 device immediately beneath it + assorted Res/Cap/diode. Probably something like a MAX6195/MAX6198. The foot print is right, but I don't think it's the right pinout as per your image & DS. Using an external 10Mhz rubidium timebase may be a better route, anyway.
marabut:
@Cyber7 :
Great news, indeed! I've just sent an inquiry to them.
By the way, output stage of HDG doesn't like non-resistive loads. With some capacitance connected to output (1m of coaxial cable is enough) square wave looks OK until you add some DC offset - then things get worse. Much worse :(
I haven't seen such ringing for years.
marabut:
--- Quote from: marabut on September 26, 2014, 09:05:44 am ---@Cyber7 :
Great news, indeed! I've just sent an inquiry to them.
--- End quote ---
... and ordered the same quantity (but 14$ shipped)
--- Quote from: marabut on September 26, 2014, 09:05:44 am ---[...] output stage of HDG doesn't like non-resistive loads.
--- End quote ---
It seems that problem appears when higher output voltages are set (starting from 4..5Vpp). When output signal amplitude is increasing , there is a point where amplification is changed (you can hear relay switching). The very moment depends on frequency (~4Vpp near 20Mhz, ~5Vpp @ 10MHz). Before switching occurs square wave is clean (more or less), after that... well, take a look at second screenshot.
Less dramatic than I've thought initially but still it's good to remember this limitation. :(
Stevie1966:
I have resolved this problem 3 days ago.
You can try the following.
Take away the capacitor C231 and C208. Then change L25 and L17 to 0 ohm.
Wish you luck. ;D
alex.forencich:
I just got a new HDG2002B, and it seems the system.inf file has been moved from /etc/ to /config/root/system.inf.
Software: 1.00.2 (140819.0)
Kernel: Linux 3.2.5
FPGA: 12
Keyboard: 3
PCB: 1004
Also, the DAC is not obscured: it is an Analog Devices TxDAC AD9747BCPZ.
I also tested it with python-usbtmc, and it seems to work. I have not yet tested it extensively, though. I will test the network connectivity with python-vxi11 as soon as I can get the parts to install the ethernet jack.
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