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Completed the tuning of the green modules and they are a massive improvement over the black modules. The output signal level is at least 5dB higher. The 25MHz, 50MHz, 75MHz,etc? spurs are no longer

During measurements there may be certain spurs that do not have an obvious cause. Are they caused by limitations of the SA? Or are they present in the input signal? An example is this two tone

Hello Earlier post regarding DC analysis of step attenuators was in relationship to design and building jumper-based attenuators.

Alan Fantastic! That information is what I was looking for when I posted the original question. Now to work up some ADC code for an Arduino so the testing process can be automated. This is all related

The attenuation at DC is exactly the same as at LF as the stray capacitance and inductance will be insignificant up to around 10MHz . I would suggest that a 50 ohm resistor is inserted in series with

I did not measure the black boards, only got one of the green boards so far. Some hints to reduce spurs: 1. Use as high Fcomp as possible.This is done by using as low R divider as possible. A ADF4351

Was just reading about pass through terminators (high impedance DUT to lower impedance test equipment input) and also the typical terminators that are specific to the impedance of the DUT and test

That is correct, in a regular, resistive attenuator with resistor, you can determine the attenuation by taking 3 measurements and solving for 3 unknown resistors. 73 de Thomas LA3PNA. ons. 27. mar.

Hello Can I test the DC attenuation of a step attenuator by using just a DC source voltage and DC voltmeter across the 50 ohm termination? This would not validate LF to HF performance but just the DC

First problem solved. The instability on +5dB output level was caused by reflections from an unused output. When properly terminated the instability disappeared and spur level reduced. Now into loop

@Thomas Did you measure black boards? If so, what spur performance did you get, in particular the ref clock spur is degrading performance to unacceptable level. Can you suggest improvement options?

These are the steps I tried till now: - Decoupling VCO and output supply: No improvement yet??(not yet improving phase noise) - Replacing the long charge pump trace with shielded connection: No

Yeah I’m interested… Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ Owner - Operator Big Signal Ranch – K9ZC Staunton, Illinois Owner – Operator Villa Grand Piton

PC SW including the source and the? Arduino SW uploaded to: /g/HBTE/files/ADF4351%20Evaluation%20SW%20from%20AD%20modified%20for%20Arduino%20interface I'm not going to "support" this

I'd like to have a copy and details relating to the mod since seems interesting from a programming exercise and for use also once I have the ADF4351 and other modules as I assume will function with

AD has create a nice open source SW package for evaluation of the ADF4351. It is intended for use with the AD ADF4351 evaluation board but these boards are very expensive and use a complex FPGA to

I was hoping the many via's on the green module where a sign of craftsmanship but I was disappointed. The black module generates many substantial spurs when used above 2GHz. The green module generates

I am asking Neils. It was his message I quoted/included in mine and he stated (in that message) that he is using a PI to control his specan.

Most of the black boards have better RF design than the green one. The green ones have some part of the PLL loop filter running under the capacitors that AC couples the output. A 2 layer design should

The below article got me thinking also about not just multilayer PCB design for shielding better with the stripline or microstrip methods thinking... also the layered designs for the traditional