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Hello, I found this video very interesting to make RF filters Rapid Prototyping RF Filters with Tape & QUCS - YouTube ( https://www.youtube.com/watch?v=drwGvATLNaw ) So I download the Qucs software to

The ELSIE free app is really good for designing various types of flilters : LP HP BP , butterworth? Chev, etc.Andy

Normal design process for this type of LPF is to first calculate the filter and ensure no capacitor is smaller than 0.5pF Than make a prototype using the calculated capacitors and find the performance

Re, some simulation It's seem good for a low pass filter 350mhz This type of filter can be difficult to design. I wonder if it is better to foresee a module that is grafted onto the motherboard for an

Hello, There is a choice on this DNF expression see here: DNF - What does DNF stand for? The Free Dictionary ( https://acronyms.thefreedictionary.com/DNF ) The Do Not Fit seems good?? --> Electronics

Hi, Could it be Do Not Fit? So those components should not be mounted. These components where probably added to the design, in case testing of the board revealed extra filtering was needed. L7 pads

My guess would be that whoever drew the schematic never entered information for those parts, therefore DNF = Did Not Find, Device Not Found, or Data Not Found.? I have done communications for some

Hello, I wanted to ask you what a DNF capacitor and a DNF inductance. I didn’t find it on the NET, unless it means that this is a value to find by ajaustant??? DNF = *D* E *F* I *N* E See this

Hello, I found for tracks with Kicad It was actually just a selection problem on a filter (Tracks not selected) So I can now edit the tracks Sorry, we learn every day. ! So I took the opportunity to

Hello Dave and others I opened your files to view with Kicad. What I would like to do is make a modification? to have only one PCB + power? to put it in a box. Even if it means not using the screen.

I registered a group a few years ago, but never used it. Today I decided to turn it into a group for the design and construction of test equipment.

Thank you for that. It was not a technique I was aware of.

One approach: https://www.giangrandi.ch/electronics/ringdownq/ringdownq.shtml There is a presumption that the effective (loaded by scope and coupled pulse generator) tank capacitor Q is good enough so

I would like some way of measuring the Q of inductors up to at least 30 MHz - 150 MHz would be nice. I have an HP 4284A Précision LCR meter (20 Hz to 1 MHz 0.05% basic accuracy) and a 4285A (75 kHz

My schematic had a print error, but the board was built with J310's .? Sorry for the error. ANG

2N3904 is a bipolar, not a FET.. just doc error? I looked up the original doc. Have you tried to replace the crystal with a resistor to see if it will oscillate? 73, Gary WB6OGD

Wally, It appears that I used the .01 on the source follower.? That's a long way from 10pf.? Could that stop the oscillation? see attached files.? Even though I originally put both oscillators on

The 100MHz crystal oscillator? is a very bad idea. A 20MHZ fundamental mode crystal is used in a 100MHz 5th overtone circuit. It is a lottery if the 20MHz crystal shows activity at it's 5th overtone,

I'm still reading also, and confused as to which is the real 100 MHz oscillator.? There are two versions of the same topology, one in the large schematic (and in the Google drive clearer image), and

I built this exact oscillator to test the J310 and the 20 MHz xtal.? Everything worked fine.? Got the correct freq on scope.Andy