Astatic D-104 Shock Hazard
If you have an Astatic D-104 (Lolly Pop) microphone it could be a shock hazard.
It probably won't have high voltage on it, but it might be grounded.
Most all electric tools today are in plastic cases to prevent electric shock.
When I was a youngster, I almost ended my life while holding my grounded D-104 and contacting some high voltage.
There are many other kinds of metal microphones that may have the same issue.
If you use a grounded microphone and want to be safe it should be rewired to remove the hard ground from the case.
Paul W0RW
| RADIOPHONE | 2021-01-15 | |
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| Re: Astatic D-104 Shock Hazard | ||
| AOC must have one them D-104S. She was on TV the other night crying about how she thought she was going to die. Reply to a comment by : N2RRA on 2020-12-20 LOL, this is a joke right? Almost ended your life? LOL | ||
| N3PM | 2021-01-04 | |
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| Astatic D-104 Shock Hazard | ||
| From N8NK-2) Opto isolation of both, the mic 'hot' line and the mic 'ground' line. Great idea. Maybe a fiber optics from the mic to the rig. One for the audio and one as a light source. Mike N3PM | ||
| DL9BDM | 2021-01-02 | |
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| Astatic D-104 Shock Hazard | ||
| But OM Paul is very wrong here: The problem is not the grounded microphone, but his other fingers on an unsafe and energized thing! If one were to think through the advice from W0RW to the end, one would have to isolate all devices with metal housings etc. A protective earth or an RCD would be called into question. It is important that the electrical equipotential bonding between all the equipment and the building installation is faultless. | ||
| AA4PB | 2020-12-28 | |
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| Astatic D-104 Shock Hazard | ||
| "If you use a grounded microphone and want to be safe it should be rewired to remove the hard ground from the case." Then be prepared for AC hum and RFI noise on your transmitted audio. | ||
| K2WH | 2020-12-27 | |
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| Astatic D-104 Shock Hazard | ||
| Let me get this straight. You are playing around with what I assume would be a HV tube rig and holding onto the metal mic at the same time which is grounded. And, you are blaming the mic because it is correctly grounded and you want to "Float" the mic above ground. You ever heard of the 100 year old saying where you keep one hand in the your pocket while working inside a HV compartment or anything containing more that 50 volts ? I guess not, the mic isn't the problem, I believe you are. | ||
| VE3WGO | 2020-12-24 | |
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| Astatic D-104 Shock Hazard | ||
| The title should be changed to "High Voltage Shock Hazard". The mic was not the hazard, the exposed HV was. There are many grounded points in a radio station, as well there should be! I agree with N6PRX... chassis ground is safety ground. The national electric code section 810 says so too. 73, Ed | ||
| N6PRX | 2020-12-24 | |
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| Astatic D-104 Shock Hazard | ||
| Sorry Sir, but as a licensed amateur radio operator of your years with at least basic electrical knowledge to achieve your license, you should know better. Chassis ground is a safety ground. Anything else is potentially above that ground (hot). Using a voltmeter would be a much safer choice than your (other) hand to check things that might be electrically hot. | ||
| K6BRN | 2020-12-23 | |
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| Re: Astatic D-104 Shock Hazard | ||
| The problem is, even IF you make the D104 electrically safe by potting it in plastic, so it can't ground anyone to death, it's still a heavy, handy club like weapon that COULD be misused by rowdy teenagers. Th only real solution is to send all of them to ME for safe disposal. Wait... I have my address around here.... somewhere.... Or - it COULD be reclassified as a tube amp "safing" device. Pop the tube amp top, toss the mike inside and wait for results. Won't take long! Reply to a comment by : N2RRA on 2020-12-20 LOL, this is a joke right? Almost ended your life? LOL | ||
| W4KVW | 2020-12-22 | |
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| Astatic D-104 Shock Hazard | ||
| I have been using the Astatic D-104 desk microphones since the late 60's & I have only ever been jolted when holding one just once & it was when we had a nearby lightning strike while I had the microphone keyed.I quickly let go of it & turned Off the radio & disconnected the Base CB Antenna.Nothing was damaged but it got my attention. I currently own 40 of the microphones in many different versions & heads.Did I mention they are by far my favorite microphones ever? | ||
| W0RW | 2020-12-21 | |
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| Re: Astatic D-104 Shock Hazard | ||
| That's right it is not the fault of the grounded mic but the added safety of an ungrounded mic (or hand tool, etc), is another layer of protection. The failure is forgetting you are holding a grounded mic/tool when near a high voltage hazards. You may find out that some older 2 wire AC rigs can knock you off your chair just by touching their chassis if you are grounded. Paul w0rw Reply to a comment by : N8WCR on 2020-12-21 The bigger question I have is, it's not the fault of the mic being grounded, it's the fault of touching a high voltage line in the first place. You could had easily been touching the chassis at the same time instead of the mic. If you are going to be around high voltage, the old thing about keeping one hand in your pocket goes. | ||
| N8WCR | 2020-12-21 | |
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| Astatic D-104 Shock Hazard | ||
| The bigger question I have is, it's not the fault of the mic being grounded, it's the fault of touching a high voltage line in the first place. You could had easily been touching the chassis at the same time instead of the mic. If you are going to be around high voltage, the old thing about keeping one hand in your pocket goes. | ||
| W0RW | 2020-12-21 | |
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| Astatic D-104 Shock Hazard | ||
| Yes, i could have been killed by an electric shock, it does happen. The same discipline is used with Electrostatic Sensitive Device part handling. It is better to set an ESD Sensitive part down on a high resistance dissipative surface than on a hard grounded surface. That way any static charge will discharge slowly and with out a destructive high current. See "Sherlock Investigates: ESD is Real”, https://www.eham.net/article/43893 Paul w0rw | ||
| KC6RWI | 2020-12-21 | |
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| Re: Astatic D-104 Shock Hazard | ||
| I didn't want to post this, but I just want to throw this out there. You need to create a path for current to flow, and yes I understand that we don't have that thought in our minds at every moment. But aren't we pretty safe standing on carpet touching plastic controls and painted surfaces? Its another thing if we are barefoot on a damp surface with metal boxes and current paths all around. I also did learn the one hand on the pocket safety measure. Reply to a comment by : KB5ZSM on 2020-12-21 They used to say as little as 50ma. could stop your heart. NOW they say it takes less then that..... Worst shock I've had was from 220v household power when I was 8. I was wiring a new dryer, sitting on a concrete floor in shorts when I learned a vary painfull lesson about testing for voltage before you dive in. Stay safe, Win kb5zsm | ||
| KB5ZSM | 2020-12-21 | |
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| Astatic D-104 Shock Hazard | ||
| They used to say as little as 50ma. could stop your heart. NOW they say it takes less then that..... Worst shock I've had was from 220v household power when I was 8. I was wiring a new dryer, sitting on a concrete floor in shorts when I learned a vary painfull lesson about testing for voltage before you dive in. Stay safe, Win kb5zsm | ||
| KD0JPE | 2020-12-21 | |
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| Re: Astatic D-104 Shock Hazard | ||
| The point is that the current ran through both arms when he contacted a high voltage, with one hand, while the other hand was holding a grounded metal microphone. It doesn't take much current to kill you when it runs between both arms. When I was a Ground Nav-Aids technician, I was taught to always keep one hand in a pocket when it was necessary to work on energized equipment. Reply to a comment by : N2RRA on 2020-12-20 LOL, this is a joke right? Almost ended your life? LOL | ||
| VE3CUI | 2020-12-20 | |
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| Astatic D-104 Shock Hazard | ||
| And here, for the entirety of my 50 year "career" as a Ham,. I thought that GROUNDED items-circuits were SAFE items-circuits... Silly me...! Guess that it REALLY woulda been OK to touch the plate caps of my 2x813 rig all along if I had the notion to, huh...?! (just WHAT am I MISSING here, anyway...?!). | ||
| N8NK | 2020-12-20 | |
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| Astatic D-104 Shock Hazard | ||
| I'd think a D-104 could be made completely safe but it would be a bit of a hassle. I'm a retired biomedical engineer who made a living off of leakage current testing and diagnosis. Yet this is vintage ham radio. Not a modern operating room. I'd think it could be made utterly safe by: 1) Re-working the keying lines so as to no longer be referenced to ground. And no longer sharing a 'common' lead with the mic element. Would probably require small decoupling caps at both ends.. unless you keep the Z of the new keying lines nice and low. But even then I'd do it. 2) Opto isolation of both, the mic 'hot' line and the mic 'ground' line. Then to stop the mic from becoming a nice high Z 'antenna'- again, decoupling to RF but not audio- and the placement of a high value resistor- something on the order of maybe 100K, etc., whatever.. to re- reference the mic 'ground' line to the transceiver/transmitter chassis. Yes, should you grab the lollypop and come into contact with 120vac, you'll get a nice surpise tingle- but no electrocution. Use too high a value of R though, and you'd lose the ground reference. It's a matter of the ratio of mic element Z to this referencing R. Keep it at least 10:1 and it should be fine. You raise a WONDERFUL and potentially life-saving point. Thanks :) | ||
| K1JRF | 2020-12-20 | |
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| Astatic D-104 Shock Hazard | ||
| Glad you are still with us as part of the above ground population paul! I got blasted twice - some of us learn once , some not. Got across a cap while scrapping a dump find when I was 7 or 8. Big ouch. In college working on an am transmitter I got across something that sent me flying across the room and on my butt. My arms tingled for a week. Learned the value of putting one hand behind your back if you must get near high voltage. I question, though, ungrounding something and just letting it float. Grounds accomplish different things and one of them can be to keep a floating item from becoming hot in the event of component fails or wiring errors. The lead singer of the Yardbirds, keith felt died from some screwed up grounds between his guitar, Mike and amps. In my rock and roll days I always checked for "juice" between equipment mostly caused by building wiring with hot neutral inversed. Still ,never thought of removing a ground to leave something floating was a good idea. Others thoughts on this? (I run several d104s also and have checked them for potential between the mic and rigs and ground and thankfully found none. Regards John K1JRF | ||
| N2RRA | 2020-12-20 | |
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| Astatic D-104 Shock Hazard | ||
| LOL, this is a joke right? Almost ended your life? LOL | ||