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Have a look at msg #5998 from Chris Corcoran… He shows a number of plots that show the resistance of the coating. You can use that to figure out the attenuation for the coating. Dr. William J.

Hmm - at 14.2 MHz with the gen set to -72dBm ( as low as it'll go without an external attenuator ), I'm seeing just a hair under S9. Not bad! 7.2Mhz - just a hair under S8. Well, on that band the BPF

I didn't say that right. The calibration of the s-meter sets the ZERO point (well... -73 db point) on the meter. That is the intercept of the equation for "S" units. You also have to calibrate (eg

Yeah and make sure you do it with the attenuator at ZERO! THEN go ahead and calibrate the RX attenuation control. Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ

I am probably oversimplifying something I may not fully understand but is there a general rule of thumb for knowing if a material may be suitable? ? Such as if it measures x ohms per square cm or

Yeah… we need a calibration procedure for this too… Looks like you have volunteered Jerry! Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ Owner - Operator Big

I was just doing this for one of my other radios, and wondered: Is the S meter display on the T41 calibrated? S9 is defined as -73dBm, or 50 microvolts @ 50 ohms. I think I'll try it out with a signal

That is on the “TO DO” list. Since this is an open/ community project… I would ask that someone with a working radio… please step up… do this as a contribution to the project if… people

I see lots of test points on the RF board, is there a list of expected voltages and signal data for each point somewhere? Trying to trouble shoot my RF board issues. Tim W4YN

I’ve never had noise from an on-board source, but that doesn’t mean it couldn’t happen. There is probably a solder bridge somewhere that is causing this… but keep it simple… to hone in on

I suspect you could spray a cheap clear coating over the top with no degradation of the graphene coating to solve the transfer problem. 20 Ohms is very low for a paint-on coating. The silver coating

I have checked adhesion to PLA+ with Rustins and it adheres very well. I was very surprised by the conductivity which was around 20 Ohms for 35mm x 35mm surface area. I would add that the graphene

Yep, its whether or not frequencies > 10MHz emanate from it ?, I like the idea of the Double sided PCB boards…. The silver plated copper paint is more reasonably priced, and as I suspect everyone

? Sent: 08 February 2025 15:46 To: [email protected] Subject: Re: [AmateurRadioBuilders] Conductive Paint I’m sure we should care about the EMI from the display too. Tell you what…

My understanding is that generally - measures that decrease emitted EMI will also decrease received EMI. - Jerry, KF6VB

842AR is unaffordium. I think with a little help, I can design a nice little 5-sided box for the back made out of PCB for about $1. Both 5” and 7” displays. Should not be hard. I’ll try one

I’m sure we should care about the EMI from the display too. Tell you what… You work on the EMR and I’ll finish getting the data line noise from propagating back into the radio… Dr. William J.

Thanks Bill, so its Electromagnetic Radiation (EMR) IN that we should be concerned about? And in particular the range below that effects the Serial Peripheral Interface (SPI) from the Teensy to the

I’ll answer #2… the SPI can run at speeds up to 10 MHz… so anything in the 0.5-10 MHz region is concerning. Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ

Both Conductive Paints look interesting. Two questions, if anyone has the energy to answer ? 1. John, have you used the Rustins paint successfully on your 3D Printed facias and if so did you use