NA -- RF Experts

[denverpilot]

How about the GHz. clock running dang near everything on the motherboard with little tiny wire antennas running that clock around the board? Last I looked logic levels were in the volt(s) range giving field strength in the volt(s)/meter range.

If you will look, every lappy I've seen has an FCC part 15 type acceptance label. And if you use the LAPpy as it was intended, that field strength is near a particularly sensitive part of your anatomy.

Jim

LOL. No lappies here... not that I use much anyway... #savethegiblets!

 

[slacktide]

I use a wireless mouse all day, every day. Should I be concerned about cancer in my clicking finger? It lasts for two years on a pair of AA batteries, so it cannot possibly be transmitting with much power.

 

[JGoodish]

You don't seem to understand field strength. There has never been any definitive issues show with even 850 mW (traditional analog cellular) at the side of someone's head let alone the milliwatts of spread spectrum we're talking about with BT. You are in bigger fields sitting in front of your computer than you are getting from your earbuds.

I do understand the concept of field strength, but also attenuation. It appears that the data is inconclusive with respect to cellular phones. Certainly, I haven't seen any conclusive data one way or the other regarding the long-term effects of direct exposure, so an elevated risk must be assumed. If you can point me to credible data to the contrary, I'd be happy to review it.


JKG

 

[JGoodish]

But I know. It's not what the cool kids do these days. Apple took the jack off their current phone. Guess which phone I won't be buying.

In the vehicles a hard mounted microphone and audio out of the stereo works perfect for true hands free and nothing need be stuffed in my ears.

There's just so many excellent options (including speakerphones and mobile speakers even, although I don't do those) there's just no real need to walk around looking like the Borg with a dongle in my ear.

Don't get me wrong, I don't like the ear dongles either. You might not like the iPhone 7, but I suspect that other manufacturers are going to follow suit.

I have BT hands free in the car, but it doesn't help me when I'm not in the car, and when I am in the car, there is sufficient background noise to make it undesirable for calls with customers.

Fortunately, I'm not talking on the phone all that much, and don't listen to music via headphones for hours on end. Even with the iPhone 7, I still use wired headphones. Just seems like ports are disappearing and wireless everything is all the rage.


JKG

 

[flyingron]

I do understand the concept of field strength, but also attenuation. It appears that the data is inconclusive with respect to cellular phones

Especially since the data collected that indicates that there might be a connection is obsolete. It was done back with the straight 850mW FM rather than the lower power spread spectrum encodings used in today's digital phones. But you are right, even back in the old days, the data was not conclusive.

 

[Ghery]

The RADAR pioneers during WWII dosed themselves rather thoroughly with microwaves of these wavelengths with no ill effects that I've heard about- microwave heating was discovered by accident when a researcher melted some chocolate in their pocket by mistake. The power employed was much higher than that used by any blue-tooth device we use.

There was the issue with people looking down the open ends of waveguides getting cataracts. The two most sensitive parts of your anatomy to damage due to heating are the cornea of your eye and the family jewels. The cornea turns opaque for much the same reason the white of an eggs turns while when you cook it. As a result we have the limits for field strength to protect people from excessive exposure. No argument about the need, but where you draw the line on the graph is a topic for discussion.

What I find amazing is the amount of power (and the cost of the equipment) you need in a lab to generate these fields when they are generated so simply by inexpensive devices in the field. It could be that the lab needs that field in a uniform area much larger than the low cost device generates in a localized area. BTW, those fields are orders of magnitude greater than the fields generated by a PC. The FCC limits in the US, and the CISPR limits (CISPR 22 or CISPR 32) used in the rest of the world are designed to protect radio communications services, and these are far more easily disrupted, hence the much lower limits. Any questions about these limits, let me know. I've only been dealing with them for over 30 years.

Ghery S. Pettit
Chair, CISPR SC I (the subcommittee that owns CISPR 22 and CISPR 32)

 

[gismo]

Maybe, but prove it for long-term continuous exposure.


JKG

The only possible effects from non-ionizing radiation are heating and induced electrical currents and for both of those it's the power level combined with the ability for your tissue to absorb energy at the transmitted frequency. And given the very low transmitter output level of any BT earpiece I think it's safe to say you're probably getting way more "radiation exposure" from the com radios in your airplane or even just walking around a major city with multiple cell towers every few blocks. Some things are worth worrying about but this isn't one of them. In fact I'll bet just worrying about this is more harmful to your long term heath than using a BT earpiece every day.