Topics

Amateurradiokits Chassis and Grounding

jsternmd
 

Just got the beautiful, high quality UBitx case for 5: Nextion and assembling.  One thing I notice is that for the many panel mounted components (pots, Mic, Key, Power, etc) there is no ground to the metal case to act as a single ground point.   I am tempted to grind away inside the panels to bare metal and then make sure the UBitx is mounted with an adequate ground to the case.  Has anyone NOT bothered to do this and how is your performance?  No looking for shortcuts but grinding to bare metal will take a lot of time and dust!

TIA  Jerry NY2KW 

Ravi Miranda
 

Hi Jerry,

Was just reading this:
https://petetest2017.files.wordpress.com/2018/11/grounding-modification.pdf

Hope this helps?

Ravi/M0RVI

On Tue, 11 Jun 2019 at 16:47, jsternmd <jsternmd@...> wrote:

Just got the beautiful, high quality UBitx case for 5: Nextion and assembling. One thing I notice is that for the many panel mounted components (pots, Mic, Key, Power, etc) there is no ground to the metal case to act as a single ground point. I am tempted to grind away inside the panels to bare metal and then make sure the UBitx is mounted with an adequate ground to the case. Has anyone NOT bothered to do this and how is your performance? No looking for shortcuts but grinding to bare metal will take a lot of time and dust!

TIA Jerry NY2KW
--
I'm here to add more value to the world than I'm using up.

Joe Puma
 

I have done this. Using a dremel I grinded around  the screw holes from inside for all the case parts and grinded the holes where jacks, pots, antenna ports connect. I did notice a before and after while dong it as far as noise from raduino, nextion screen and RF issues. 

Definitely worth doing. I suggested to Sunil to have these contact points tapped off before painting. From what I understand, it’s not so simple. Dremel away. 

Joe
Kd2nfc 



On Jun 11, 2019, at 11:47 AM, jsternmd <jsternmd@...> wrote:

Just got the beautiful, high quality UBitx case for 5: Nextion and assembling.  One thing I notice is that for the many panel mounted components (pots, Mic, Key, Power, etc) there is no ground to the metal case to act as a single ground point.   I am tempted to grind away inside the panels to bare metal and then make sure the UBitx is mounted with an adequate ground to the case.  Has anyone NOT bothered to do this and how is your performance?  No looking for shortcuts but grinding to bare metal will take a lot of time and dust!

TIA  Jerry NY2KW 

Curt
 

Ravi, Joe - good info - I remember doing something to expose some metal on the nice case. 

remember this is a DIY project -- Sunil would be happy to have us expose some metal wherever we deem suitable!  we have the technology (use a drill bit slightly larger than the hole or whatever one might have). 

enjoy the nice hardware, from India and other parts of the globe! 

Curt

jsternmd
 

Thanks to all for confirming.  Now to get out the dremel tool.  

73 Jerry NY2KW

Ian Reeve
 

Hi, I have just completed a build using the case designed for the 3.5 inch nextion.I did carefully with a counter sinking bit take off the minimum of paint surrounding the antenna,and front jacks. I used a single point on the chassis to take the power Jack negative,the antenna Jack return and the earth returns from the Jack panel.This ties together electrically the back panel,the front panel and the main chassis.The lid is earthed via one screw to the back panel.   Ian M0IDR


From: BITX20@groups.io <BITX20@groups.io> on behalf of Curt via Groups.Io <wb8yyy@...>
Sent: Tuesday, June 11, 2019 6:17:14 PM
To: BITX20@groups.io
Subject: Re: [BITX20] Amateurradiokits Chassis and Grounding
 
Ravi, Joe - good info - I remember doing something to expose some metal on the nice case. 

remember this is a DIY project -- Sunil would be happy to have us expose some metal wherever we deem suitable!  we have the technology (use a drill bit slightly larger than the hole or whatever one might have). 

enjoy the nice hardware, from India and other parts of the globe! 

Curt

Dexter N Muir
 

Modern wood-drills (used to be called 'bits' for brace-and-bit use) might help, in an ordinary drill (hand- or low-speed) to 'peel off ' a circular 'land' of paint (or whatever). They have a flat 'cutting' edge with a centralizing peak that ought to be the right size/proportion.

_Dave_ K0MBT
 

It is just a coat of paint. A light sanding with 36-100grit would take about 5 minutes.

The real question is does it make a difference? Inquiring minds want to know.
Dave

Joe Puma
 

It’s really not that easy to scratch off, it’s definitely a task, Especially when your case is half built and you need to get to the holes on the inside. 

Does it work? You’ll have to ask Faraday himself or resort to any of his writings regarding a faraday cage. 

Faraday cage or Faraday shield is an enclosure used to block electromagnetic fields. A Faraday shield may be formed by a continuous covering of conductive material, or in the case of a Faraday cage, by a mesh of such materials.

Joe
Kd2nfc 


On Jun 12, 2019, at 9:17 AM, d balfour <davesters@...> wrote:

It is just a coat of paint. A light sanding with 36-100grit would take about 5 minutes.

The real question is does it make a difference? Inquiring minds want to know.
Dave



Mike Yancey
 

I'd gotten the parts, but hadn't done this (YET!) but: I highly recommend it - I felt some tingly RF on a screw head on my mic and a couple of other points.
I used a two-battery power mechanism: 1 battery for the radio, 1 'stacked' (electrically) for 24-V on the PA. And at about 24-26 Watts, you can get a tingle!

Mike Yancey, KM5Z
Dallas, Texas, USA


On Tue, Jun 11, 2019 at 10:54 AM, Ravi Miranda wrote:

toggle quoted messageShow quoted text

Satish Chandorkar
 

The easyest way is to get a small conical shape grinding stone
and drilling a hole to mount a bolt to hold grounding connection
and grind around the drilled hole lightly to remove the paint


On Wed, Jun 12, 2019 at 7:37 PM Mike Yancey <mikeyancey@...> wrote:

I'd gotten the parts, but hadn't done this (YET!) but: I highly recommend it - I felt some tingly RF on a screw head on my mic and a couple of other points.
I used a two-battery power mechanism: 1 battery for the radio, 1 'stacked' (electrically) for 24-V on the PA. And at about 24-26 Watts, you can get a tingle!

Mike Yancey, KM5Z
Dallas, Texas, USA


On Tue, Jun 11, 2019 at 10:54 AM, Ravi Miranda wrote:

toggle quoted messageShow quoted text

_Dave_ K0MBT
 

Re Faraday cage. I live in a steel sided and roofed house the panels are not bonded together but yet no cell phone service inside. That was not my question.

When I first got a radio going had rf on the mic. The solution for me was to put an rf choke at the antenna hub. You might consider that solution rather than trying to fight it in the radio.

The finish can be removed pretty easy, too easy from my perspective. Around the case holes it has chipped off on it's own. It looks like powder coating.

Joe Puma
 

I’d say use whatever method solves your problem. There is a benefit in making sure grounds from connectors are touching the metal case and why not have all the case pieces bonded, it just helps all around. I have the black case with 5” screen. The paint is thick but scraping real good does get it off. I used a file at times and my dremel. Trying to scratch with a flat screwdriver was tricky. It really a no brainer if your starting the build. But I had everything already assembled before I thought to remove the paint. Not ideal.

Btw I live in a house made of wood and sheetrock. My cell service indoors is horrible as well.

Joe
Kd2nfc

On Jun 12, 2019, at 4:36 PM, d balfour <davesters@...> wrote:

Re Faraday cage. I live in a steel sided and roofed house the panels are not bonded together but yet no cell phone service inside. That was not my question.

When I first got a radio going had rf on the mic. The solution for me was to put an rf choke at the antenna hub. You might consider that solution rather than trying to fight it in the radio.

The finish can be removed pretty easy, too easy from my perspective. Around the case holes it has chipped off on it's own. It looks like powder coating.



pershing123@...
 

What kind of paint do you suppose is on those chassis?

Alan
N6DII

jsternmd
 

Looks like powder-coated.  I used a Dremel, wore a facemask and did it outside the house!

 

Jerry NY2KW

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of pershing123 via Groups.Io
Sent: Friday, June 14, 2019 7:22 PM
To: BITX20@groups.io
Subject: Re: [BITX20] Amateurradiokits Chassis and Grounding

 

What kind of paint do you suppose is on those chassis?

Alan
N6DII

Dexter N Muir
 

Powder-coat is often better chipped away, hence my earlier brace-bit suggestion. Likely much less dusty too :) Untried, and possibly less effective on fresh coating. If tried please report.
de ZL2DEX

Ian Reeve
 

It can be scratched off but looks untidy.I use a counter sinking drill bit,the sort you use to sink cheese head screws flush,and that gives a neat paint free surround to the screw holes and potentiometer holes etc.


From: BITX20@groups.io <BITX20@groups.io> on behalf of Dexter N Muir <dexy@...>
Sent: Saturday, June 15, 2019 7:47:27 AM
To: BITX20@groups.io
Subject: Re: [BITX20] Amateurradiokits Chassis and Grounding
 
Powder-coat is often better chipped away, hence my earlier brace-bit suggestion. Likely much less dusty too :) Untried, and possibly less effective on fresh coating. If tried please report.
de ZL2DEX

jsternmd
 

Yes Dremel makes it look untidy but I only did the inside and addes star washers to make cood contact.  Checked resistances and all less than 0.1 Ohm

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of Ian Reeve
Sent: Saturday, June 15, 2019 4:04 AM
To: BITX20@groups.io
Subject: Re: [BITX20] Amateurradiokits Chassis and Grounding

 

It can be scratched off but looks untidy.I use a counter sinking drill bit,the sort you use to sink cheese head screws flush,and that gives a neat paint free surround to the screw holes and potentiometer holes etc.


From: BITX20@groups.io <BITX20@groups.io> on behalf of Dexter N Muir <dexy@...>
Sent: Saturday, June 15, 2019 7:47:27 AM
To: BITX20@groups.io
Subject: Re: [BITX20] Amateurradiokits Chassis and Grounding

 

Powder-coat is often better chipped away, hence my earlier brace-bit suggestion. Likely much less dusty too :) Untried, and possibly less effective on fresh coating. If tried please report.
de ZL2DEX

tedlong17@...
 

 Hi Jerry,

   Aren't Sunil's cases awesome??! My slacker's solution to the chassis grounding issue was to apply a little methylene chloride based paint remover to the
interior side of the mounting holes with a cotton swab, give it a couple of minutes to work, clean it off with a wet cloth, and give the bare metal a touch of emery cloth.
  Worked like a charm.

73 de,
Ted
K4TML

jsternmd
 

NOW YOU TELL ME J

 

I used a dremel tool and made some dust.  Methylene chloride… I wont forget that!

 

Jerry

 

From: BITX20@groups.io [mailto:BITX20@groups.io] On Behalf Of tedlong17@...
Sent: Wednesday, July 3, 2019 5:20 PM
To: BITX20@groups.io
Subject: Re: [BITX20] Amateurradiokits Chassis and Grounding

 

 Hi Jerry,

   Aren't Sunil's cases awesome??! My slacker's solution to the chassis grounding issue was to apply a little methylene chloride based paint remover to the
interior side of the mounting holes with a cotton swab, give it a couple of minutes to work, clean it off with a wet cloth, and give the bare metal a touch of emery cloth.
  Worked like a charm.

73 de,
Ted
K4TML