Is anyone familiar with these? For example the PSG1000 or the ESG1000?
The ESG1000 seems to be very similar to the PSG1000 but without the SINAD meter and a few other minor differences:
- sweep duration is fixed and cannot be varied
- no sellcall mode
- no DC power option
- no facility to alter the synthesizer rate - internal 1kHz tone only
- no mVemf or µVemf buttons
- no RAD PM button
There may be other as yet undiscovered differences, but otherwise the unit seems very similar in layout and function to the PSG1000.
I would specifically like to further understand the function of the DCFM button and the kHzFM button. From the manual it appears that the generator is capable of producing both AM and FM signals? I am uncertain as to the function of the DCFM button, but the manual states:
Quote:
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Originally Posted by Farnell Instructions/Service Manual for PSG1000
a) For modulatin level the three possible terminating keys are % AM, kHz FM and RAD PM. The resulting level is displayed in the four digit modulation level window.
For % AM the displayed resolution is 0.1%, and 0.01 radian for RAD PM.
With kHz FM, the displayed resolution varies depending upon the carrier frequency and the modulation level (see specification).
"b) The modulation circuits may be d.c. coupled with %AM, kHz FM by selecting DCFM.
In the % AM mode the isolating capacitor in the modulation input path is shorted out so that all the modulation paths are DC coupled.
When selected with kHz FM or RAD PM the synthesizer loop integrater is held at the last tuning voltage thus disabling the correction loop. The unlocked carrier can now be frequency modulated with a d.c. voltage at the modulation input.
By selecting MOF OFF the modulation signal is isolated from the carrier circuits thus removing the modulation. Additionally, MOD OFF deselects DC FM (if selected), permitting re-locking of the carrier.
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The reference to Radians can be disregarded as this unit does not have that function, but I had supposed that pressing kHz FM would put the generator into FM modulation mode. Instead, it appears to be stuck in AM mode and the kHz FM button does nothing except for showing 'ignore' on the display. I am unfortunately none the wiser as to the purpose of the DC FM button.
The other puzzle is the sweep button. This does perform a very slow sweep. On the the PSG1000 apparently this can be varied between 2 and 200 seconds, but on this unit, it appears to be fixed as there is no opportunity to input the number of seconds despite the button legend. It also puzzles me that there is no trigger output which means that the sweep cannot synchronised and viewed on a scope?
Finally, despit the instrument telling me that its GPIB address is 16, there is no response from the GPIB interface so it seems there are multiple problems which require investigating. However, as a staring point, it would be useful to at least understand how the kHz FM and DC FM buttons *should* work.
Any information, or even a copy of the ESG1000 manual would be appreciated.