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Re: Conductive Paint
开云体育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. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ ? Owner - Operator Big Signal Ranch – K9ZC Staunton, Illinois ? Owner – Operator Villa Grand Piton – J68HZ Soufriere, St. Lucia W.I. Rent it: ? Moderator: North American QRO Group at Groups.IO. Moderator: Amateur Radio Builders Group at Groups.IO. ? email:? bill@... ? ? From: [email protected] <[email protected]> On Behalf Of Doug W via groups.io
Sent: Sunday, February 9, 2025 12:04 PM To: [email protected] Subject: Re: [AmateurRadioBuilders] Conductive Paint ? 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 something like that. |
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Re: [SoftwareControlledHamRadio] Calibrate S meter?
I didn't say that right. The calibration of the s-meter sets the ZERO point
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(well... -73 db point) on the meter. That is the intercept of the equation for "S" units. You also have to calibrate (eg determine) the SLOPE of the curve using the attenuator (because we know the attenuator is correct). S-units (an any input) = S-meter calibration point at fake -73 db + "Detected signal strength in S units above zero" So above S=0, "Where Detected signal strength in S units above s=0" = gain(S=full scale - S=0) * received signal strength in fake dbs. You need to set the attenuator at two different points to resolve the slope. This is very crude so don't kill me... just fix it... Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ Owner - Operator Big Signal Ranch – K9ZC Staunton, Illinois Owner – Operator Villa Grand Piton – J68HZ Soufriere, St. Lucia W.I. Rent it: www.VillaGrandPiton.com Moderator: North American QRO Group at Groups.IO. Moderator: Amateur Radio Builders Group at Groups.IO. email:? bill@... -----Original Message-----
From: [email protected] <[email protected]> On Behalf Of K9HZ Sent: Sunday, February 9, 2025 12:25 PM To: [email protected]; [email protected] Subject: Re: [SoftwareControlledHamRadio] Calibrate S meter? 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 Owner - Operator Big Signal Ranch – K9ZC Staunton, Illinois Owner – Operator Villa Grand Piton – J68HZ Soufriere, St. Lucia W.I. Rent it: www.VillaGrandPiton.com Moderator: North American QRO Group at Groups.IO. Moderator: Amateur Radio Builders Group at Groups.IO. email:? bill@... -----Original Message----- From: [email protected] <[email protected]> On Behalf Of jerry-KF6VB Sent: Sunday, February 9, 2025 12:23 PM To: [email protected] Subject: Re: [SoftwareControlledHamRadio] Calibrate S meter? On 2025-02-09 10:11, jjpurdum via groups.io wrote: No. It is an approximation based on comparing S signals on commercial *** Makes sense. That's actually what I figured :). I think such calibration would need to be per-band. - Jerry, KF6VB |
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Re: [SoftwareControlledHamRadio] Calibrate S meter?
Yeah and make sure you do it with the attenuator at ZERO! THEN go ahead
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and calibrate the RX attenuation control. Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ Owner - Operator Big Signal Ranch – K9ZC Staunton, Illinois Owner – Operator Villa Grand Piton – J68HZ Soufriere, St. Lucia W.I. Rent it: www.VillaGrandPiton.com Moderator: North American QRO Group at Groups.IO. Moderator: Amateur Radio Builders Group at Groups.IO. email:? bill@... -----Original Message-----
From: [email protected] <[email protected]> On Behalf Of jerry-KF6VB Sent: Sunday, February 9, 2025 12:23 PM To: [email protected] Subject: Re: [SoftwareControlledHamRadio] Calibrate S meter? On 2025-02-09 10:11, jjpurdum via groups.io wrote: No. It is an approximation based on comparing S signals on commercial *** Makes sense. That's actually what I figured :). I think such calibration would need to be per-band. - Jerry, KF6VB |
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Re: Calibrate S meter?
开云体育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 Signal Ranch – K9ZC Staunton, Illinois ? Owner – Operator Villa Grand Piton – J68HZ Soufriere, St. Lucia W.I. Rent it: ? Moderator: North American QRO Group at Groups.IO. Moderator: Amateur Radio Builders Group at Groups.IO. ? email:? bill@... ? ? From: [email protected] <[email protected]> On Behalf Of jerry-KF6VB
Sent: Sunday, February 9, 2025 11:44 AM To: [email protected] Cc: [email protected] Subject: [AmateurRadioBuilders] Calibrate S meter? ? I was just doing this for one of my other radios, and wondered: Is the S |
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Re: V12 RF Board
开云体育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 want it in the short term. ??I know there are guys on channel that did this for a living… that could bang it out in about 10 minutes. ? ? Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ ? Owner - Operator Big Signal Ranch – K9ZC Staunton, Illinois ? Owner – Operator Villa Grand Piton – J68HZ Soufriere, St. Lucia W.I. Rent it: ? Moderator: North American QRO Group at Groups.IO. Moderator: Amateur Radio Builders Group at Groups.IO. ? email:? bill@... ? ? From: [email protected] <[email protected]> On Behalf Of Tim via groups.io
Sent: Sunday, February 9, 2025 11:09 AM To: [email protected] Subject: [AmateurRadioBuilders] V12 RF Board ? 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 |
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Re: [SoftwareControlledHamRadio] Excessive Noise
开云体育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 the area of the circuitry with the issue.? Oliver had some good input… if the clocks both look good… you can follow a calibrated input into the receiver front end… past the transformer (TP4), then past the attenuator and the gain stage (TP6)… if all that works there is only the mixer U1 and the filters at TP5 and TP3. ? Here is another great diagnostic tool that a lot of people forget about.?? You can take the RX I/Q output at J1 into your computer through the stereo input… load a SDR program like SDR Console and demodulate the signals as if it were the Main board.? [Note: this also means that with the addition of a simple software subroutine/ control module to the suite of existing provided modules in any of the SDR PC programs, anyone could build only the RF board and have a fully functional QRP Transceiver.? Other boards could be added to additional functionality]. ? ? Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ ? Owner - Operator Big Signal Ranch – K9ZC Staunton, Illinois ? Owner – Operator Villa Grand Piton – J68HZ Soufriere, St. Lucia W.I. Rent it: ? Moderator: North American QRO Group at Groups.IO. Moderator: Amateur Radio Builders Group at Groups.IO. ? email:? bill@... ? ? From: [email protected] <[email protected]> On Behalf Of epif18 via groups.io
Sent: Sunday, February 9, 2025 9:43 AM To: [email protected] Subject: Re: [SoftwareControlledHamRadio] Excessive Noise ? Thanks Bill, that sounds like a plan.? I just finished hooking up my sig gen to one of the antenna with an output of -40dbm and 60dbm of attenuation, 7MHz AM, RF gain set at 0 and I could see and hear the signal (faint).? So right now, I have a sensitivity of -100dbm.? I do want to hook up my old linear power supply to see if I have switcher noise too.? Just out of curiosity, if you have ever found noise in Main or RF, what do you think the cause may be? Thanks again, Mark KU3O |
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Re: Conductive Paint
开云体育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 looks like a much better bet for conductivity but the cost in intolerable. ? ? Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ ? Owner - Operator Big Signal Ranch – K9ZC Staunton, Illinois ? Owner – Operator Villa Grand Piton – J68HZ Soufriere, St. Lucia W.I. Rent it: ? Moderator: North American QRO Group at Groups.IO. Moderator: Amateur Radio Builders Group at Groups.IO. ? email:? bill@... ? ? From: [email protected] <[email protected]> On Behalf Of John
Sent: Sunday, February 9, 2025 1:55 AM To: [email protected] Subject: Re: [AmateurRadioBuilders] Conductive Paint ? 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. |
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Re: Conductive Paint
开云体育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 tonight. ? ? Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ ? Owner - Operator Big Signal Ranch – K9ZC Staunton, Illinois ? Owner – Operator Villa Grand Piton – J68HZ Soufriere, St. Lucia W.I. Rent it: ? Moderator: North American QRO Group at Groups.IO. Moderator: Amateur Radio Builders Group at Groups.IO. ? email:? bill@... ? ? From: [email protected] <[email protected]> On Behalf Of K9HZ
Sent: Saturday, February 8, 2025 6:29 AM To: [email protected] Subject: Re: [AmateurRadioBuilders] Conductive Paint ? 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 ? Owner - Operator Big Signal Ranch – K9ZC Staunton, Illinois ? Owner – Operator Villa Grand Piton – J68HZ Soufriere, St. Lucia W.I. Rent it: ? Moderator: North American QRO Group at Groups.IO. Moderator: Amateur Radio Builders Group at Groups.IO. ? email:? bill@... ? ? From: [email protected] <[email protected]> On Behalf Of chris corcoran via groups.io ? Both Conductive Paints look interesting. Two questions, if anyone has the energy to answer ?
? The MG Chemicals tech sheets imply that adhesion to Polypropylene is poor, not sure where PETG or PLA would fit. ? ? Silver paint (842AR) attenuation is so much better $$$$$$$ , even the Nickel based paint is much better. Not sure if the Carbon paint ?would just keep the elephants away… ?
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From: [email protected] <[email protected]> On Behalf Of John ? Check this out, they are a trusted very well established comapany and the tech sheet makes interesting reading. Not sure about supply in the States, over here MG Chemical is very expensive. |
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Re: Conductive Paint
开云体育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. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ VP2EHZ ? Owner - Operator Big Signal Ranch – K9ZC Staunton, Illinois ? Owner – Operator Villa Grand Piton – J68HZ Soufriere, St. Lucia W.I. Rent it: ? Moderator: North American QRO Group at Groups.IO. Moderator: Amateur Radio Builders Group at Groups.IO. ? email:? bill@... ? ? From: [email protected] <[email protected]> On Behalf Of chris corcoran via groups.io
Sent: Saturday, February 8, 2025 8:18 AM To: [email protected] Subject: Re: [AmateurRadioBuilders] Conductive Paint ? 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 display? ? ? Should we care about EMR from the device out? ? ? Chris M0YGH ? From: [email protected] <[email protected]> On Behalf Of K9HZ ? 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 ? Owner - Operator Big Signal Ranch – K9ZC Staunton, Illinois ? Owner – Operator Villa Grand Piton – J68HZ Soufriere, St. Lucia W.I. Rent it: ? Moderator: North American QRO Group at Groups.IO. Moderator: Amateur Radio Builders Group at Groups.IO. ? email:? bill@... ? |
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Re: Conductive Paint
开云体育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 ? Owner - Operator Big Signal Ranch – K9ZC Staunton, Illinois ? Owner – Operator Villa Grand Piton – J68HZ Soufriere, St. Lucia W.I. Rent it: ? Moderator: North American QRO Group at Groups.IO. Moderator: Amateur Radio Builders Group at Groups.IO. ? email:? bill@... ? ? From: [email protected] <[email protected]> On Behalf Of chris corcoran via groups.io
Sent: Saturday, February 8, 2025 4:57 AM To: [email protected] Subject: Re: [AmateurRadioBuilders] Conductive Paint ? Both Conductive Paints look interesting. Two questions, if anyone has the energy to answer ?
? The MG Chemicals tech sheets imply that adhesion to Polypropylene is poor, not sure where PETG or PLA would fit. ? ? Silver paint (842AR) attenuation is so much better $$$$$$$ , even the Nickel based paint is much better. Not sure if the Carbon paint ?would just keep the elephants away… ?
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From: [email protected] <[email protected]> On Behalf Of John ? Check this out, they are a trusted very well established comapany and the tech sheet makes interesting reading. Not sure about supply in the States, over here MG Chemical is very expensive. |
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Re: Conductive Paint
开云体育Both Conductive Paints look interesting. Two questions, if anyone has the energy to answer ?
? The MG Chemicals tech sheets imply that adhesion to Polypropylene is poor, not sure where PETG or PLA would fit. ? ? Silver paint (842AR) attenuation is so much better $$$$$$$ , even the Nickel based paint is much better. Not sure if the Carbon paint ?would just keep the elephants away… ?
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From: [email protected] <[email protected]>
On Behalf Of John
Sent: 07 February 2025 10:18 To: [email protected] Subject: Re: [AmateurRadioBuilders] Conductive Paint ? Check this out, they are a trusted very well established comapany and the tech sheet makes interesting reading. Not sure about supply in the States, over here MG Chemical is very expensive. |
K9HZ