|10-20-2010 10:57 PM|
An old Hammurland - haven't seen one in years. I had one, don't remember which one, 2 tuning dials and a BFO, loved it till the smoke fell out!
I used a Drake 2b - and a home brew CW transmitter. You had to be technical in those days, as opposed to just paying a fee now.
I was going to get my EE degree - specializing in antennas - til I realized that wasn't for me. I ended up buying and selling businesses (17,) houses, apartments, and shopping malls. Much more fun and far more profitable.
|10-20-2010 09:34 PM|
Thanks guys and melissas6570 also. I'll start my own post and would like to continue this EMI discussion. I didn't mean to take over on Dewry's post.
Sparky; I fly out of northeast PHL, I know the building.
RRich; I just bought an old Hammurland HQ-110 tonite. 73, N3JQD.
|10-20-2010 11:47 AM|
|rrich||Well I guess that proves it - another "I know someone."|
|10-20-2010 10:23 AM|
How is your coax routed. Is it in the tub or underneath.
Come visit us next week. Holmesburg Amateur Radio Club.
|10-20-2010 10:05 AM|
|Gate53||I have no ed in the matter but I have found that using plastic coated 1/4 dog cable to do my grounding for my CB and radio works well.|
|10-20-2010 09:58 AM|
|10-20-2010 09:05 AM|
|10-19-2010 11:00 PM|
|10-19-2010 10:48 PM|
Unfortunately this is a Google-ing match. The point of this was to answer his question whether it was safe or not. The answer simply yes he is safe. The history lesson is nice and yes bsck in the day that would affect his electronics, but since we have ADVANCED technology past 1963 by over 40 years with current safeguards and grounding he will be fine. As with anything, unplugging the battery and removing current flow is good with ANY scenario. Also, recommending what you as a welder do is good advise.
So his question is answered, you will be fine, but as a precaution and to save Google having to search more articles to win the argument, a good suggestion is removing the battery.
|10-19-2010 10:07 PM|
For those that are interested - and for the non-believers that electrical energy is transmitted when there's a spark.
The very early transmitters used what they called a spark gap. That spark-generated electrical noise radiates, not just between the electrodes but all over. The spark was turned on and off to generate a “modulated” noise - Morse Code was used to communicate information.
When electric welding a strong current in the form of a spark is generated, melting the work piece. It's not unlike the early spark transmitters. (Who remembers Morse Code? I had to be able to use it at 25 words per minute to get my Ham license (General) years ago in 1963.) WA6EMZ
Energy was transmitted through the air or any other conductive medium. That energy can be detrimental to modern day electronics - like your PCM.
If interested, do a little searching about Marconi, Nicola Tesla, and others. Simply search “spark transmitters” or the names mentioned. The early history of radio communication is very interesting. There is an interesting article even about how the Titanic, using spark transmitters had trouble communicating with the rescue ship.
Spark-gap transmitter - Wikipedia, the free encyclopedia
High Frequency Noise
Unfortunately reading about it is far more complicated than simply disconnecting the battery.
Is this the Pirate Board? It seems like it by the way playing it safe is resisted so much.
|10-19-2010 09:39 PM|
not gonna be able to quote the extensive background that everyone else gets to here....i only get to go off of the 2.5 years of schooling/training and $450,000 (yeah i think that's crazy too) navy education for computer and elctronics....but being as those big things in the water are no longer made of wood there is a very extensive training with regards to EMI and RF and all the other fun electronics acronyms you get to cover when going over affects of welding and such. in your scenario, it will be fine without having to disconnect as long as you are closely grounded. unfortunately, after training and brainwashing the principles and training into me....i'm still forced to disconnect all power and unplug the right cables so i don't get in trouble.
moral of the story.....you'll be fine, and yes i have welded too so there aren't arguments. good luck on your project
|10-19-2010 09:18 PM|
|Dewry636||Well, WOW... This thread got a ton of reaction! I didn't expect all of the replies and everyone on here is really informative! I will side with caution and just go ahead and unplug it.... Thanks for all of the replies! ---- It seems I will have to wait until the end of the month before I even get to weld on my jeep...... Busy, Busy at work! Which is a good thing after finally getting a new job after collecting partial unemployment for over a year....... I am happy to work!|
|10-19-2010 09:14 PM|
Jerry B. is right, just weld the thing. The PCM will be fine.
Mellissas6570, interesting background. I believe that if any AC currents are flowing due to EMF or low freq. RF, it would be better for the PCM to be grounded/connected in order to return such current to ground. As opposed to the PCM floating without a ground. I'm a radio amateur, N3JQD, and Xmit high power RF from my Wrangler, typically anywhere from 3.8Mhz to 7.29 Mhz at up to 500W. My only problem is the darn fuel pump noise be received by the Xcvr. My entire frame and body are grounded everywhere using braided flat cable. The hood, the frame, the exhaust is even grounded thus all metal is bonded to ground and creating a suitable groundplane for Xmit. So, anyway to attenuate the fuel pump noise or eliminate it? Sorry, to hijack your post Dewry.
|10-19-2010 08:51 PM|
I do not want to argue this point because there are some very well educated people who say it should be OK to leave the PCM, etc. connected. But there is one reason rrich gave that is hard to argue with. Disconnecting the PCM is so simple and easy to do why not do it.
There are also those here who say they have welded for a long time and never had an issue, I used to be one of those lucky people too. But as recently as two years ago I fried two computers welding on vehicles with the computer connected so now I disconnect them. Maybe I had some weird oddity happen, I don't know. The ground was close (within 3 feet) but obviously could have been closer.
Just adding my thoughts and personal experience is all.
|10-19-2010 08:00 PM|
|baja||Alright man its suppertime and momma made pasgetti!!!!!Nums nums nums!Later good people later!|
|10-19-2010 07:40 PM|
|10-19-2010 07:40 PM|
|baja||Ha nobody knows what I said to s3nt3nc3dabcdefg!|
|10-19-2010 07:39 PM|
|10-19-2010 07:28 PM|
I have no welding knowledge so I have nothing to add to this thread...I know my buddy is a mechanic and I've never seen him unplug the battery or computer before welding in a vehicle, but as mentioned, he always puts his ground clamp near where he's welding.
|10-19-2010 07:26 PM|
|baja||AH the good old days.|
|10-19-2010 07:21 PM|
|10-19-2010 07:11 PM|
|10-19-2010 07:09 PM|
|baja||Yes but maybe I was a specialist at one time!|
|10-19-2010 07:07 PM|
|10-19-2010 07:06 PM|
|10-19-2010 06:35 PM|
Someones getting his feelings hurt. What everyone here is basically telling you is that you do not have to. In fact, I just called a diesel mechanic who just finished schooling at Penn State and said that he's actually been instructed to leave the battery connected to act at worst, as a buffer.
And putting quotations around words doesn't make it a quote. Not a single person here used the phrase "expert" or "in the know."
See The “Blog” of “Unnecessary” Quotation Marks
I think what people have provided are significant backgrounds either through certifications or experience that do make them experts on the topic and can answer in an expert fashion what the proper precautions are. What constitutes an expert to you?
Do you remove the engine when you wash under the hood because you run the risk of getting water in the spark plug well?
Not to mention, your credibility lends to the fact that despite worrying about your PCM, you still weld while your doctors are saying not to.
|10-19-2010 05:50 PM|
Settle down beavis
I for one can back up my education and 20+ years of professional electronics experience in the field day in and day out.
I can also back up that I have personally welded everything from a jeep to a volvo 18 wheeler, to a kubota tractor all having ECMs and never had a problem. I do not have a pacemaker, but that wasn't the question the original poster asked.
|10-19-2010 05:00 PM|
THEN GO AHEAD AND DO IT!
Do you think anyone really cares that you do it? Who cares if YOU damage YOURS? Try the new bullets - nobody will care about it either. After the first few tries, let us know how it felt.
My main objection is when so called "experts" that "claim" to be EE'S or welders or "in the know" because they "know someone that --," advise people to do things that are detrimental, risky, or just downright unsafe.
Especially when the preventative step is so simple. Or maybe it's not so simple for some to disconnect and ground the battery cable. Less than 2 minutes is clearly a waste of time for them - or do they have to hire it done?
Comment about the pacemaker - it does not have wires running all over me to run headlights, brakelights, turnsignals, a heater, AC, instruments, stereos, or accessories to act as long antennas. The longest wires are 2 wires about 3" long connecting into the heart muscle - and those are dual conductors with a shield. But still it gets affected.
|10-19-2010 03:21 PM|
|10-19-2010 03:17 PM|
Go figure. Its not made to be in a nasty environment. Look where the PCM is located. It is in a very bad place. Take a speca and a antenna and look around with the Jeep running. Its nasty. I am very shocked that you have not had a issue around the motor while its running.
Yes I know. I am a NARTE certified electromagnetic interference engineer. I have worked for UL conducting Medical testing and electronic compleance testing, and the Gov. doing MIL-STD-461, DO-160, HEMP, and HIRF testing.
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