TENMARS TM-196 3-Axis RF Field Meter

Kingrex

Well-Known Member
Feb 3, 2019
2,800
2,307
350
I get so much concern over RF I decided to try a meter. I figured $300 or so is not too much to chance. What I am really wondering is what I can do with the information. What if I do find RF in a room. Well, we all know I will. Its everywhere. Cell towers, phones, wifi. Its pervasive.

My hope is on a new builds where people are starting from a stripped room, we can locate a quiet location to set the rack. Or maybe mesh wire can be installed behind the drywall to block a transmitter.
I have been in rooms that are RF sealed. It looked like a fine mesh ones lays in a concrete poor. On another project for a Microsoft data center we welded a steel 3 sided box over the primary power wires running underground. Noise can be blocked before it enters your system. My hope is that If we can block it before it gets into the equipment and power lines, then less filters are needed to try and remove it.

I'm a little afraid this will take me down a rabbit hole. I can see my wife asking why a large metal mesh is on the wall in the living room.
Rex
 
  • Like
Reactions: zerostargeneral

microstrip

VIP/Donor
May 30, 2010
20,806
4,698
2,790
Portugal
Radio frequency officially ranges from range from above 20 kHz to around 300 GHz. What is the bandwidth you are considering?
 

Kingrex

Well-Known Member
Feb 3, 2019
2,800
2,307
350
Radio frequency officially ranges from range from above 20 kHz to around 300 GHz. What is the bandwidth you are considering?
I did not see any meters higher than 8GHz. Even the ones at supply houses. What is 5G running at. That is the one I hear may be a real killer. I gather it is extremely powerful. I want to see if I can detect the to be expected radio noise from AM/FM, cellular and WiFi. And hopefully find some directionality as to where it is coming from. If there is the chance I can find it, know the direction and block it, I would spend up the $3K for a meter. Maybe more. It really depends on, can anything be done about it. If I can't see where its coming from and I cant block it, then its not a very useful tool.
 
  • Like
Reactions: wil and microstrip

wil

Well-Known Member
Jul 22, 2015
1,482
1,506
428
I've read that there are paints and wallpaper which are claimed to block RF.
 

Kingrex

Well-Known Member
Feb 3, 2019
2,800
2,307
350
If paint or wallpaper had metal in it, it could block certain frequencies.

It appears this meter will see most RF. AT&T 5G is way up there at 16 to 22GHZ. Tmobile is 4GHz. 4G is around 5GHz. There is a learning curve here. Especially on what will block what frequency.
 

Kingrex

Well-Known Member
Feb 3, 2019
2,800
2,307
350
There appear to be a lot of paints and fabrics to block RF. Graphite infused paint that requires a ground clip is about $250 a gallon.
What you have to remember with any shielding, an 1/8" per say is a mile to an RF wave. Your shield has to be perfect. Maybe. Understanding directionality helps. But my house for example, I have radio towers as well as cell towers everywhere. Literally in every direction. I could only block RF with a full shield. Glass wrap, curtains, in wall fabrick, paint inside and out. Then maybe.

Or, you treat RF like lighting. You arrest it to ground. All of it, no. I don't think that is possible. But you can get some to shunt to earth. The attached is an example of why most peoples grounding is only marginally effective. Do you see the mistake?
 

Attachments

  • imagejpeg_0(2).jpg
    imagejpeg_0(2).jpg
    154.7 KB · Views: 5

DasguteOhr

Well-Known Member
Sep 26, 2013
2,354
2,511
645
Germany
then connect a cruiser with a length of 1m to the connection flag. then wrap the connection point with a waterproof tar bandage. then you have 30 years of rest and always a low-resistance connection.
this is standard in germany i am a trained electrician.
61KS6Iu6ydL._AC_SS450_.jpg IMG_0598_800x600.jpg
 

Attachments

  • IMG_0598_800x600.jpg
    IMG_0598_800x600.jpg
    238 KB · Views: 1

Kingrex

Well-Known Member
Feb 3, 2019
2,800
2,307
350
There appear to be a lot of paints and fabrics to block RF. Graphite infused paint that requires a ground clip is about $250 a gallon.
What you have to remember with any shielding, an 1/8" per say is a mile to an RF wave. Your shield has to be perfect. Maybe. Understanding directionality helps. But my house for example, I have radio towers as well as cell towers everywhere. Literally in every direction. I could only block RF with a full shield. Glass wrap, curtains, in wall fabrick, paint inside and out. Then maybe.

Or, you treat RF like lighting. You arrest it to ground. All of it, no. I don't think that is possible. But you can get some to shunt to earth. The attached is an example of why most peoples grounding is only marginally effective. Do you see the mistake?
The clamp itself may be a code violation. It may be to large for the rebar.

You must treat RF like Lightning. If this were inspected by a competent inspector familiar with the process he would probably ask to have a simple change made that could make all the difference in the world for this to work properly.

FWIW, you never arrest lightning into a concrete encased electrode. The bolt will instantaneously heat the concrete and shatter it. It only goes to rods. Rods are better than plates. This install is not for lightning, but I'm saying you treat it the same to shunt high frequency noise to earth. The grounding electrode conductor is not connected to the rebar correctly. Why.
 

DasguteOhr

Well-Known Member
Sep 26, 2013
2,354
2,511
645
Germany
the connection from must be made corrosion-proof otherwise you will quickly lose the low-resistance connection. therefore tar bandage. Tinplate is used as a shield to keep high frequencies away. These cables are great as they have an extra layer of ferrite powder around each core. eupen-emc-com-ferrit-filterkabel-3x1qmm-meterware.jpg
 

Kingrex

Well-Known Member
Feb 3, 2019
2,800
2,307
350
the connection from must be made corrosion-proof otherwise you will quickly lose the low-resistance connection. therefore tar bandage. Tinplate is used as a shield to keep high frequencies away. These cables are great as they have an extra layer of ferrite powder around each core. View attachment 84539
How I wish we could use cable as such in the USA. I am trying to get a 10,000 foot spool of solid THWN, twisted, with the hot, neutral and ground all jacketed. We have never really had a shielded cable like you have, or Oyaide makes, unless it is MC Cable.

The problem I see with MC is it has to land in a metal box. That means you have to have isolated ground receptacles. It is the way we do recording studio when it is critical noise is rejected. A home system is different. IMO. I will specify whichever you want.

We do have JPS Labs which is also a tinned stranded wire. It is industrial and resists corrosion better than plain copper. Especially in harsh environments such as marine and manufacturing. I have listened to both and I personally find the tinned to have a color that is not as neutral as bare copper. And once it is behind the wall its not coming out. You can use a tinned copper power cord and get the same affect if you need to alter the sound in a way that suites your taste. I try and set the foundation as dynamic, quiet and neutral as I can get it. Power cords and interconnects are more predictable when bare copper is used as that is the foundation of most every home in the USA.

And I 100% agree the ground connection needs to be covered. Oxidization is always present in high quantity at every earth ground connection I uncover. Even after a year the cable is starting to blacken. It is very apparent when you use a green pad to polish it before reconnection and sealing.
Rex
 
  • Like
Reactions: DasguteOhr

DasguteOhr

Well-Known Member
Sep 26, 2013
2,354
2,511
645
Germany
Too bad the cable is really good, have you ever test this Belden cable. it's very stiff, almost like solidcore, but offers very good EMI shielding and sounds good.
s-l400 (1).jpg

earlier, when it was still known how to build tube amplifiers.
Sensitive input tubes, phono amplifiers and FM tuners with shielding tube bases were built. the tube sockets were connected to the amplifier ground and thus protected from high radiation frequencies.
It works really good
2020-12-1515.57.04_1600x.jpg
 
Last edited:

About us

  • What’s Best Forum is THE forum for high end audio, product reviews, advice and sharing experiences on the best of everything else. This is THE place where audiophiles and audio companies discuss vintage, contemporary and new audio products, music servers, music streamers, computer audio, digital-to-analog converters, turntables, phono stages, cartridges, reel-to-reel tape machines, speakers, headphones and tube and solid-state amplification. Founded in 2010 What’s Best Forum invites intelligent and courteous people of all interests and backgrounds to describe and discuss the best of everything. From beginners to life-long hobbyists to industry professionals, we enjoy learning about new things and meeting new people, and participating in spirited debates.

Quick Navigation

User Menu

Steve Williams
Site Founder | Site Owner | Administrator
Ron Resnick
Site Co-Owner | Administrator
Julian (The Fixer)
Website Build | Marketing Managersing