The AM Forum

wasn't paying attention and got bit. 800volts melted a pin hole into the tip of my finger.

you are one of the lucky ones .... probably didn't feel so lucky at the time ....hurts like hell !!!

Felt just like getting burned by my soldering iron.  didn't feel the typical shock one would expect. 

RF?

Probably the current went through your finger and out the other side of the same finger or that same hand.

If it had gone from one hand to the other through your chest, you might not be posting about  it.

You are fortunate.

rf and dc combined is my bet. I got that offa the first viking 2 I ever had.

I think you're right.  I feel and see a slight burn mark mark on the surface on the other side of the tip.   Didn't notice it before.

whydjou stick yer finger in there in the first place? Well at least it turned out for the best.

Yep, HV RF (and DC)  usually cauterizes the wound - no blood.

Back in Aug, 1972, it was a hot summer day and I was sweaty. I came across 800VDC, from hand to hand, through the chest. I was paralyzed from the waist up as it passed through. Good thing my legs still worked. I stood up and ran backwards and the cable attached to the rig ripped it out of my hands. It was a long 2-3 seconds and I hit the floor.  I stayed conscious but was buzzed.

It took at least 5 weeks for the large wound in my right hand to close up and partially heal. It was ripped open flesh, but no blood. Third degree burns - real nasty. It kept getting infected and should have been closed up with stitches I guess. It really grossed out my girlfriend... ;D   The other hand had just two tiny snake-bite holes that caused no problems at all.

I guess the bottom line is for this much damage to be done to my hands meant the current thru the chest was pretty big. Doesn't make sense it wasn't lethal.

T

Cause...  I'm an idiot!   

After being put under for an out patient procedure today, they told me not to do anything dangerous afterwards.  What do I go a do??
 

As Tom/JJ knows I was troubleshooting a problem with my FT-102.  I was poking around in the PA area when the xcvr was powered on trying to trace an intermittent on the Ant. relay.  The insulated tool I was using slipped and my finger touched one of the plate leads on a 6146.  I learned one thing about the FT102, even though the heater switch is off the HV is on.  Didn't know that or better yet, forgot.  Getting old and buzzardly I guess.

Cause... I'm an idiot...

Yikes, thank God it wasn't an amp with 3 or more KV.   Wow, a reminder to me to do stuff around B+ like that with one hand in my pocket.   Tom, you are probably still here because your accident happened when you were 30 years younger.

I am always a bit nervous around the big stuff, but I have as much respect for anything with high voltage. Been nailed by a few tube audio amps thoise tube regulated power supplies and 400V is scary enough. I was sort of poking fun but I am glad no one was injured seriously.

I learned about RF when I was a novice. I built the little slat board 6L6 transmitter and was adjusting the coupling of the output coils. Fingertip touched the tank cap and felt like a beesting. Note smell of burning flesh and nice little hole drilled through fingernail; no blood. Hmmm... make note to self that 300VDC and superimposed RF hurts real bad. My rule is "Be real careful when you're being real careful around high potentials".

Glad to hear you're O.K. and still able to tell about it. Be safe!

Phil

Too much current and it starts to bypass the heart. Same reason the electric chair was overkill and didn't kill several people on the first tries.

Wow snake up your ass had an good electric belt. I think you need a day off.

Did it smell like steak cookin' ?

I got it on a Hallicrafters HT32B a few years back. Opened the top and held it with one hand, started taking off the plate clips on the 6146's with the other........Wwwooonnkkkkk! It was on "standby". Im sure that one went through the old ticker.

Its serious stuff. If you let your guard down, it will get you , and might get you good and dead. When ya lose respect, its time to hang it up for a while.

Was troubleshooting a receiver on its side on the bench.  My then 8 year old daughter came in and was watching me and reached up towards some of the exposed connections. I instinctively barked loudly at her and then calmed down explaining that I was not mad, just worried because one could get really hurt by touching those parts.

While still looking and talking to her I reached up to start working on the rig again and my finger got zapped good with the expected results.

"Oh she said innocently, I see what you mean."

Another time when my wife was out of the house and the kids (probably 6 and 5) were around I was working on the GK 400 when I got the full treatment. Knocked me right onto the floor where I felt very light headed and hurt.

Hearing the crash they came running down the hall and seeing me flat on the floor down asked with worry if I was OK.

Not wanting to alarm them I said "I'm fine, just resting from my radio work for awhile"

Carl
/KPD

Watch it closely. RF burn is not goodness.
It will take a while to heal

Fred

they call me RF Burns in the mobile, waving my hand. kinda hurts. ow ow

"I learned one thing about the FT102, even though the heater switch is off the HV is on.  Didn't know that or better yet, forgot."


Bob,

Do you remember maybe 4 years ago when Gary/ INR got a bad belt from his FT-102? It was the same thing - he thought the heater switch in the "off" position killed the HV - but NOT!   I made the same mistake here once, but was just a tickle.

Thinking about it, all the time I've run the FT-102 in receive with the heater off, the HV was in there cooking - what a waste.  That shud be modified.


Dave, interesting about the current bypassing the heart when large. I guess the original DNA designers knew someday we'd be playing with HV eventually and worked that failsafe in... ;D

T

Fred, The whole tip of my finger is now sore. It feels as if I ran it across some rough sand paper. Where yesterday it was just the burn mark that hurt.  Will keep an eye on it.

Frank, You're so eloquent  :D But you're right too!

Tom,
I do remember Gary saying that, now. And if I remember right he took a pretty good jolt, much worse than I.  Like you it was a tickle and a burn rather than a bonafide hands-on-go-through-the-body jolt.  He was very lucky. I didn't get the heart palpitations or sore muscles that typically follow after getting hit even with something less, thankfully.  

I agree on an HV mod or at least an indicator that it is on. It is a waste of power come to think of it. It's to bad the HV meter position doesn't show HV in the receive position.  That would help a tiny bit.  I put a note on the cage stating: Warning: HV On When Heaters Off.  That should be a good reminder for me in the future.

I think the reason the HV is on is because it uses just one transformer that supplies all the SS low voltages too. So kill that primary and the RX dies too.  There would need to be a relay in series with the HV secondary to open it before it got to the rectifier diodes. The relay shud be good for 1200v at least too.  That little heater switch wouldn't cut it.

T

Agree.  probably all the more reason to have a full-time HV indicator on the rig.

Good idea -

Ya know, just a simple BIG, JUMBO RED LED connected to any 12V point on the board (with a 500 ohm resistor) could be mounted (glued) to a conspicuous place. It wud look you in the eyes all the time the cover is off reminding you to "come a little bit closer, you're my kind of man, so big and so strong...."

T

How about a neon bulb and big series resistor right across the HV output.
You can even use a neon panel indicator with an additional series resistor.

In my case a sledge hammer,  hovering over my head, without a dropping resistor would be best.

To paraphrase a line often used to describe another human endeavor -- "When it comes to getting bit on ham gear HV, there's only two kinds of folks -- those that admit it, and those that lie about it".

Back forty-some-odd years ago, when I was a newly minted teen-age Novice/Technician, I bought a partially completed power supply project from a fellow ham who'd lost interest in finishing it. I'd picked up an ARC-5 xmtr from somewhere and figured on mounting it on the half of the chassis that wasn't occupied by PS components.

Got it home and the first order of business was, of course, to measure the voltage. I plugged it in (note the order of procedures here), made sure the power switch was pushed down to "OFF" (it wasn't labeled, but everybody knows down is OFF), turned the chassis over, connected the ground lead of my VOM and went to connect the hot lead.

After I picked myself up off the floor, set my chair back on all four legs and explained to my rather surprised mother, who was in the next room, how I knew words like that, I unplugged the PS (getting smarter by the minute, ain't I?), reconnected the test leads and discovered that the power switch had been installed so that DOWN = ON. Turned out it was about 650 volts that had launched me halfway across the room.

I learned two things from that I've never forgotten: 1> Take nothing for granted, and 2> When you're working with HV, work with one hand behind your back.

Hope your punctured paw heals up soon, Bob.

ldb
K5WLF