Valiant Tripping GFI

[W1KSZ]

Just to add another arrow to the suffering ...

My benches in the garage all feed off GFI outlets. Just plugging in the Valiant
causes it to trip.

My thinking is those ceramic by-pass caps on the AC line. Does anyone see a
problem with removing them ? Or maybe has a suggestion for a less heavy-
handed method ?

Tnx, Dick, W1KSZ

[KA2DZT]

Try removing the caps on the AC line.  They were use back then to reduce TVI from the AC line.  I never use them, you don't need them.  I also never run anything off GFIs which are another PITA.

Fred

[w4bfs]

the gfci unit will trip at 6 to 7 ma current imbalance between line and neutral …. a .01 uFd disc ceramic has

Xc = 26.5 kOhms (provided the decimal point is correct) which will yield a peak current of 6.4 mA … so you can see that a single bypass cap of this value could cause nuisance tripping it is placed between line and ground

[W1KSZ]

I am stuck with the GFI's unless I want to rip them out, which I really
don't. They are there for safety purposes.

So, time to rip out all those by-pass caps.

I remember an R-390 I had did the same thing until I removed that
line filter monstrosity. I wasn't concerned about eavesdropping !!

Thanks for the reply,

73, Dick, W1KSZ

[N2DTS]

I used to trip the GFI outlets in the kitchen till I installed filters on the microwave.
You may have a lot of problems with them tripping from RF.

 

[W1KSZ]

Valiant was not even turned on. The GFI popped when I plugged it in (actually
above 1/2 sec after). That led me to believe the by-pass caps were at fault,
which they were.

73, Dick, W1KSZ

[N2DTS]

I know, but RF can trip them also.

[wa3dsp]

A GFI is a balanced device so equal and good caps from either side of the line to ground will not trip a good GFI.  Many older rigs do not use proper caps for line filtering. Chances are that one of the caps is more leaky than the other. You can purchase caps specifically made for line filtering.

Everything and more you want to know about it....

http://www.justradios.com/safetytips.html

[KA2DZT]

A GFI is a balanced device so equal and good caps from either side of the line to ground will not trip a good GFI.  Many older rigs do not use proper caps for line filtering. Chances are that one of the caps is more leaky than the other. You can purchase caps specifically made for line filtering.

Everything and more you want to know about it....

http://www.justradios.com/safetytips.html

I read through most of that paper,  better to just leave the line caps out.  They're not needed.  They probably do little to reduce noise.  I think they were used to keep RF from getting out on the AC line from the equipment.

Best thing to do with any old piece of equipment is to install a 3 wire grounded line cord.  If the equipment has a power xfmr no static is going past that anyway.  Any static on the AC line will most likely get pick up by the antenna,  line caps are not going to help that.

The chance of those caps shorting are more of a problem to worry about.

Old AC DC radios without xfmrs can be a problem,  these should have a proper line cord connected so the chassis is always connected to the neutral.

One of the schematics shown was a line filter.  Again, it's there to keep noise and RF from getting out onto the line from the equipment itself.  Most modern equipment without power xfmrs (like TVs) have these filters.

Fred

[N2DTS]

A few years ago, my wife had the kitchen enlarged, and they put in GFI outlets.
They are not old.

I was tripping them until I put a ferrite on the power cord for the microwave, which is the only thing plugged in all the time.

[KL7OF]

Just what are these GFI outlets protecting us from? Is home electrocution a big problem?  Are housewives getting shocked from the electric eggbeater?? 

[KB2WIG]

Just what are these GFI outlets protecting us from? Is home electrocution a big problem?  Are housewives getting shocked from the electric eggbeater?? 

As much as I love the nanny state, and the faith that the government always knows watt is the best for me, the following site may be of interest. 

http://bss.fnal.gov/fire/Electrial_Safety.pdf

klc

[N2DTS]

Well, we need crappy GFI outlets made in China to protect us from getting electrocuted from crappy appliances from China.

Water, metal, and 120vac is not a great combo.
And people can be stupid, like the guy who needed to replace the light in his pool.
He lowered the water to below the light, then jumped into the pool with his electric drill to drill out the rusty screws.
It did not end well.

And its amazing how little it takes under some situations.
I was once working at a new building, they had a wet concrete floor, lots of dirt and dust, and temp lighting which was strings of insulated 14 gage wire with bulb holders (plastic) with regular bulbs in them.
I just brushed against the wires and flew 10 feet across the room.

Insulated wire, clothes on, sneakers, yet I got enough current to toss me.

[WQ9E]

The way the Valiant is set up you have 4 caps on one side of the line and two on the other, the discrepancy is from also using a filter on one side of the switched 110V for the antenna relay.

I had one GFI outlet in the house that picked up RF when on 75 meters.  I had noticed it sometimes tripped after operation on 3885 and then one morning my sister-in-law was visiting and heard my voice coming from an outlet in the bathroom  Some ferrite took care of the problem.

GFI has been a code requirement for many areas of the home for some time now.  They aren't nearly as touchy as arc fault breakers which could be a real pain if they come into common use.  A friend went through this when he was doing some temporary consulting work and the condo he rented was built with them.  I don't recall him mentioning the brand but they didn't like RF anywhere from HF to UHF and he wasn't running much power.

[wa3dsp]

The ARRL has setup a test lab for GFI's and AFI's and they are working with the industry to improve RF interference problems. There is a story in (I think) the January or February  issue of QST.

Home electrocutions were much more common before grounded devices and GFI's came about. They do save lives. They are code for many circuits in a home but if you want to change them out go right ahead understanding the risks. If you have insurance issues you might have a problem. Also if you sell you house there will probably be an inspection to see if you comply with code.

GFI's break the circuit in under 10ms and will reduce or eliminate the arc created when you accidentally put that screwdriver from line (or neutral) to ground.

Electrical problems account for a large percentage of house fires.

The use of a AC line filter on a transmitter is strictly to eliminate RF getting out on the line. The Johnson equipment had Pi filters on all lines going in and out. That is the big air wound enameled wire coils you see all over. I removed them all in my Ranger rebuild and replaced the line filter with a ferrite and a cap that is designed for line voltage.  This was written up in ER a number of years ago. The author compared the attenuation of the Johnson arrangement to a modern ferrite replacement. I guess not surprisingly the Johnson filters were not that effective.