Dave KB7JS The Latest Musings from Dave, KB7JS


Harmful Effects from Cell Phone RF
by Dave, KB7JS

This WEB site is a focal point for the more audacious warnings about the effects of too much exposure to random RF, but still, there is some truth to it.


In all my years fooling around with Radio and other various ways to waste electrons, I have never encountered anyone who “knowingly” had a serious health issue due to RF radiation.  Then again, if RF scrambles or destroys brain dells, who would know?  In the 70’s, I knew a gentleman who operated his own CB Radio retail and repair business.  In the back room, he was constructing linear amplifiers (Illegal as hell) so his customers could chat with Australia as they trucked down the highway.  His name was Bill Merchant, and you would find him at his store every day, usually on the phone, , 8 to 10 hours a day using one of the original 27 Mhz walkabout portable phones.   He died at 49 from a brain tumor.   Hmmmmmm, must have been the cigarettes his customers exposed him to.

History, common wisdom, and statistics seem to support that moderate power at lower frequencies, such as those used for HAM radio,  has never been very dangerous, except to the idiots that insist on grabbing hold of the antenna feed.  Even at very high power levels, as long as the system is relatively resonant, the levels of EMR are not significant. My father and his brother both operated HAM radio in the late 40’s and early 50’s, using home brew open chassis transmitters or repurposed surplus military gear, operating AM Phone and CW at 400-500 Watts.  RF output was through an open wire feeder running from the transmitter, up the wall, out the basement window, and the side of the house to the antenna. Transmitter power was “estimated” from the DC Input in those days using Ohms Law P=IE, and they tuned their radios by watching a front panel current meter, dipping the grid and peaking the plate.  They had no way of measuring SWR on the transmission line, after all, as long as it didn’t shoot sparks you were good to go.  Nor did they have any means to estimate Field strength at their antenna.  And yet, they didn’t kill or even annoy any of their neighbors chickens.  Both of them lived well into their 90’s, and it wasn’t RF exposure that finally caught up to them, it was more likely Jack Daniels.

Today, Government Regulation expects us all to accurately estimate Effective Isotropic Radiated Power to prevent dangerous radiation that might harm our neighbors.

I learned in the USAF that high the frequency stuff, RF radiation above 400 Mhz, is far more dangerous at even medium power levels.  The F-4 Phantom had an X-Band illumination radar transmitter used with the Sparrow Missile.  The missile used two receivers, one in the nose, one in the tail.  Before launch, the antennas were fed with the transmit signal and the reflected signal from the target.  Once launched, the Sparrow homed on the reflected signal while monitoring the transmitted signal from the F-4, performing signal processing to calculate the range based on Doppler shift.  When the frequencies swapped, it had arrived at the target and the warhead was detonated. That Radar had sufficient power, and 12 dB gain concentrated by a parabolic dish antenna, to kill you in very short order, or at least ruin your day with some very deep nasty burns. We used to demonstrate that it could ignite a standard 25B flashbulb at distances out to 500 feet from the antenna. Shipboard weapons tracking radars used by the Navy are far worse.

There is considerable discussion ongoing about this subject, most of it driven by the unknowns about the widespread deployment of new cellular nodes for 5G, which will introduce high power RF emitters in abundance in high density populated areas, even in residential neighborhoods. Even though the problem of RF exposure has been studied for some time, just the differences in frequency, bandwidth, power, and modulation type makes a huge difference, and there are as yet almost no published studies regarding 5G since all of the technology is new.  Of course, Cellular providers want to make tons more money as quickly as possible, and the government is involved in the confusion, the FCC inundated by licensing requests, and the hurry up let’s get this done. Yes, but people’s lives, or at least their livelihood, are at risk.  But not to worry, your Government is investigating. Yeah, sure.

But, I’m not going to panic, I’ve been electronically connected one way or another most of my life, and having spent most of my life around RF radiators of some kind, you could say I’m a living example of how safe it can be.

Seriously, I treat RF exposure with a healthy dose of respect and avoid getting too close, especially to high power radiators.  Still, the majority of the population is daily holding a Microwatt to Milliwatt transmitter next to their head for several hours each day, and the effects are still under continuous debate.
When half of the population develops incurable brain cramps, then the Government will say, “gee, those people participated in reckless behavior”.  Duh.

We have to know more, and proceed with understanding and caution.



Has Civility Died on 75?
by Dave, KB7JS

The vile behavior of so many operators on 75 Meters these days is disgusting, but not necessarily a new phenomenon, just a nasty evolution of bad manners by what I have to classify as low-life's with a radio.

As I remember, in the 60's and early 70's,almost everyone on the bands, with very few exceptions, operated with excellent manners and practiced deliberate courtesy.  All of the many people I had contacts with were class act people, the long Rag Chew was the typical contact, and not once over a continuous operating stretch of  many years did I encounter bad manners, harassment, jamming, or other obnoxious behavior.  Amateur Radio was a gentlemen's sport and hobby then, where civility, courteous behavior, and a universal willingness to be helpful were the common traits shared by all. 

In the 1960's, I had the opportunity to occasionally operate at the MARS station at Da Nang AB, South Vietnam.  We tried to operate round the clock to provide phone patch and message passing communications by military personnel with their families and loved ones back home.  Although we had excellent equipment, we were often challenged by band conditions, but we would always be accommodated by countless state-side Hams who would stay up to all hours simply to facilitate our communications.  That kind of comradery and selfless service has become a rarity.  Today, many operators will openly object to lengthy phone-patch operations as it conflicts with their search for contacts to verify WAS, WAC, WAZ, or whatever awards they might pursue.  Others will openly interfere with arrogant disdain for a frequency in use.

(for more, click here)

More Dave

Regarding Amplifiers: Personally, I really don't understand the Amp craze.  What ever happened to the tenet of using the minimum power necessary?  While they are very popular and useful in poor conditions, poor propagation is what it is.  A better antenna will always get better results than can be obtained by pumping more power into a marginal one.  I sincerely believe it's the contest mentality that has caused them to be abused and used all the time to simply kick up the receiving stations S-meter.  Yeah, they will give you a stronger signal, but is that really necessary?   My experience on the bands is that they are too often used all the time, even in good conditions, which makes your signal so powerful that it becomes simply interference for the poor guys on the other side of the planet that you can't hear.   I'd rather have an honest QSO within the limits of the conditions and call it a day.   I have recently encountered some amplifier elitist's on 40 and 80 that won't acknowledge your call if you aren't running an Amp like they are.   I have witnessed them telling individuals to get an Amp or go away.

- Up to a Mile Away? Are you Kidding? : POT GROWERS CAUSE BIG STATIC FOR HAM RADIO

- Check out this site for band conditions: CONUS HF BAND CONDX

- Good read, very interesting, but it will give you a brain cramp: FM BACKSCATTER

- On the Lighter Side: BRITSH CARJACKING

- My Lips are stuck to my Keyer!!: WINTER FIELD DAY ASSOCIATION

-This little $149 tool can help you understand why things don't work: BIT SCOPE: MICRO ANALYSER & SCOPE

- Grasping the difference between regular batteries and deep cycle batteries: A LAYMAN'S GUIDE TO BATTERIES

- And some tasty Battery FAQs: BATTERY FAQ

- Video Tour of the Johnson Viking Valiant: TOUR FROM THE BENCH OF K7PP -- <> -- AND, TUNING IT UP


. . . and from Ken -- LEARN ALL ABOUT AMATEUR RADIO de F6DQM -- See his site! http://f6dqm.free.fr/amateurradio.htm

Learning CW

-- The Art and Skill of Radio-Telegraphy - Click Here for PDF file (clean file)

-- CW Ops Homework - Click

New Sites to Explore

-- NEW! Electro ReSales - Novel Electronic Gadgets that will make your day!

SPUTNIK: Yesterday was the 60th anniversary of the launch of Sputnik 1, the first earth satellite.  Dave says, I clearly remember standing in the back yard looking for it to fly over ( we saw it often, there was nothing like “Light Pollution” then.  And Dad and I sat in front of the old Hammarlund SP-600 listening on 20.005 Mhz for its pulse CW signal as it passed by. Later, in 1962, my first “real” car was a ’57 Bel Air hardtop, manufactured the same week that Sputnik launched.  More impressive, however, is the pace of everything we experienced in a very short span of our lifetime. Just 12 years after Sputnik 1 beeped it’s way around the earth, Neil Armstrong walked on the moon."

Sputnik 1 was a cathartic moment that shaped a tremendous shift in our daily lives, and launched focused investment and growth in science and technology.  It may seem strange that I chose the word “cathartic” to describe the event that launched a sudden change in our society.  By definition, it represents a purging or relief of emotional tensions.  And yet, I believe that is what happened to our society as a whole, the casting off of beliefs and prejudices that formed the day to day expectations of Americans and were keeping us from looking outside our comfort zone, achieving goals that had been beyond our dreams and expectations.  Personally, it became the driving force that awakened my curiosity and lead me to pursue a lifetime career in science and technology.

Great words, Dave. This underlines how regular people become hams. Passion drives 90% of it and a chance encounter is the trigger that plants the seed. We all got here in different ways and it is our life experiences that made it happen. Or, think of it this way: Somehow, the Big Guy gave us a nudge and we in a mass of sweat and consternation did the rest of it. Grin, in your case you can say, "The Russians made me do it!"


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