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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 $$$$$$$ , even the Nickel based paint is much better. Not sure if the Carbon paint ?would just keep the elephants away… ?
?
From: [email protected] <[email protected]> On Behalf Of John ? Check this out, they are a trusted very well established comapany and the tech sheet makes interesting reading. Not sure about supply in the States, over here MG Chemical is very expensive. |
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Re: Conductive Paint
开云体育Both Conductive Paints look interesting. Two questions, if anyone has the energy to answer ?
? The MG Chemicals tech sheets imply that adhesion to Polypropylene is poor, not sure where PETG or PLA would fit. ? ? Silver paint (842AR) attenuation is so much better $$$$$$$ , even the Nickel based paint is much better. Not sure if the Carbon paint ?would just keep the elephants away… ?
?
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. |
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Display Driver 3.3V ONLY board
开云体育Another Friday share… The new Display Driver board.? This is the 3.3V ONLY board.? It’s the cheaper of the two options.? Use it of you don’t (and won’t) use 5V to power your display (if you will or do, use the other one).? ? Bare Board: ?
? Front side complete: ? Plugs into the “DISPLAY” connector on the right side of the MAIN board shown here:
? It can go on the bottom of the board too… just keep the SAME orientation of the driver board to the Main board but put the connectors on the opposite side of the boards (all three shown on the wrong side of the MAIN and Driver boards for use on the bottom of the MAIN board): ? ? 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 - J68HZ Soufriere, St. Lucia W.I. Rent it: ? email:??bill@... ? |
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Show and Tell Friday #1
开云体育Just some Friday sharing… Here is a finished dual encoder board with 3D Printed knobs (all out on the GITHUB).? Replaced TWO encoders.? One ribbon cable from the encoder board to the Fron Panel Electronics (FPE) board (one of 8 possible FPE boards BTW!).?? I guess I should make a video of the combo AF/RF gain on one encoder…
? 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: Level Shifting
Yes. Use ULN280x parts... I use them for everything where I need to drive
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stuff... 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: jerry <jerry@...> Sent: Friday, February 7, 2025 12:19 PM To: [email protected] Cc: K9HZ <bill@...> Subject: Level Shifting Hello, This has very little to do with the T41... I have this homebrew linear. It interfaces with my T41 quite nicely. Just like the T41, it has a Teensy 4.1 inside. Bands are chosen using Yaesu "BCD" band codes. Four wires, each one can be "high" or "low" gives you a four bit code and 16 possible bands. The standard is that "high" is near 5V, and "low" is near 0V. Just like in the old TTL days. The Teensies, however are 3.3V devices. Any inconveniences are compensated by the fact that they are WAY faster than any 5V Arduino. When I built the linear, I converted the 5V ( from an FTDX10 ) to 3.3V with a resistive voltage divider. When I built the T41, I converted the 3.3V from the Teensy to 5V using an open-collector transistor switch in each line. The problem with this is that the noise immunity is not good. So when the linear starts transmitting, RF gets into the band-chooser lines. The linear changes to a different band, and the protection circuit then says "Oh you have the wrong LPF", and shuts off the power. I *love* that protection circuit. I am still on my first MRF1K50. No amount of bypassing fixed it. I have bypassing and RF chokes at the T41, I have bypassing at the linear. I shielded the cable between them. I mostly fixed it by saying "We never change bands during transmit, so ignore those lines at that time". How to know that we're in transmit? Software on the Teensy monitors the drain current of the MRF1K50. If it's greater than zero, we're transmitting. But for some reason, it still does it on 10M if I run more than 800W or so. Doubtless RF starts coming out before the Teensy notices the drain current.... I guess. ANYWAY - the recent discussion about level shifters intrigued me. Is there an IC solution that's better than open-collector drivers and resistive voltage dividers? One that has decent noise immunity? It does not have to be fast; these lines are essentially DC. - Jerry, KF6VB |
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Re: Conductive Paint
开云体育All interesting stuff… I see Prusa are marketing a PETG Magnetite ?which may have decent electromagnetic shielding. ?Not cheap tho they also have a V0 filament, ?Prusament PETG V0 is the one-in-the-world UL-certified self-extinguishing PETG filament. Similar to the regular Prusament PETG, it is a tough material with good thermal resistance. Its use is universal but it is especially suitable for housings and insulating parts in electronics, due to its self-extinguishing properties ? Other products are available by other manufacturers, probably… ? Expensive, but once I’ve finished everything I’ll but a reel and see how I get on… ? If anyone is buying a 3D printer and consider a Prusa, use this code @Chris_80193, there is a small referral benefit…. ?, their new Core1 looks magic… I’ve upgraded my mk3 to mk3S, to mk4 and added a multicolour MMU2->MMU3 ? My neighbour after much deliberation (support was his clincher, not the cheapest) went for a resin printer, he’s going to try some lost wax bronze casting ?for his 4” traction engines he’s building, a whole new world… ? For your amusement, form over substance maybe….no idea why I printed the numbers….. not as if I had to take off my socks ? ?
? ? ? ? ? ? From: [email protected] <[email protected]>
On Behalf Of K9HZ
Sent: 07 February 2025 14:37 To: [email protected] Subject: Re: [AmateurRadioBuilders] Conductive Paint ? This one I’ve used for building guitars… ? ? 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 ? 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This one I’ve used for building guitars… ? ? 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: Friday, February 7, 2025 4:18 AM 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. |
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Re: Display Adapter
开云体育Exactly. ? ? 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 Terrance Robertson, KN6ZDE via groups.io
Sent: Thursday, February 6, 2025 9:45 PM To: [email protected] Subject: Re: [AmateurRadioBuilders] Display Adapter ? Yeah, since it's a digital isolator, it needs an independent 3.3V source when the display is run at 5V.? At least for it to be plug and play. |
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Re: [SoftwareControlledHamRadio] [AmateurRadioBuilders] Display Adapter
No. data line voltages at 3.3 and VSS to the display requlator of 5V...
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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: Thursday, February 6, 2025 9:25 PM To: [email protected] Cc: [email protected] Subject: Re: [SoftwareControlledHamRadio] [AmateurRadioBuilders] Display Adapter By "operating the display at 5V", you mean 5V logic? - Jerry, KF6VB On 2025-02-06 19:17, K9HZ wrote: This one will work for operating the display at 3.3V and 5V. It's |
K9HZ