Using RF coax cable as DC Solar PV cable - Page 2

Xringer · 02-15-13, 05:05 PM

Hey Steve, I would never try to feed AC neutral anywhere on a coax shield.
That's just too dangerous.
In 1968, I purchased 6 meter rec converter from an old Ham.
It came with a DIY power supply. It was a plain metal box with a transformer on top.
It worked fine, so I never opened the box.. It had a non-polarized AC plug.

After a near disaster, I opened the box and found the transformer was only
6.3vac for the tube's filaments! The 170VDC B+ for the tube plates
was directly rectified right off the grid!!

The neutral side of the plug was the box ground.
The hot line connected to a big diode and a cap.

The day I plugged it in the wrong way, it was snowing and raining.
The hot side was on the outside coax shield. I never noticed anything.

Later I heard on the scanner, 'A power line has fallen on the fences'..
My neighbor told me that there was sparks when he closed the gate.
I then realized, The 6M antenna was on the fence!
I disconnected the converter and opened the box.. Dang!
I ran out and told the power company guys what happened.
They were glad to get out of the weather.
My wife heard on the scanner, "Some ham radio nut had power connected to his fence".
All the fences on the block were connected together. And, all the steel poles
were sitting in wet concrete blocks in the wet ground.

All that ground should have shorted and blown the 15A fuse in the basement.
I went down and checked it the next day. It was blown!
It had been blown before we moved in..
But, some other tenant had placed a penny behind it..

I looked over both basement fuse boxes and found 4 more pennies!

ecomodded · 02-15-13, 05:17 PM

Quote:

Originally Posted by Xringer

Is that labeled as a 220v~ 3,000 amps??
That's not really going to work with a 0.66 megawatt load is it?

What uses that much power??

~~~

An AC~ breaker that had large self-wiping contacts and
a good air-gap when open might to the job on DC.
You could try it.

On any kind of switch for DC power switching,
one thing you want is speed. It's going to arc anyways,
but if you minimize the time it's arcing, the contacts will last longer.

I had thought the 3,000 amps would suffice , Lord knows what circuit that is for, industrial I suspect or another Chinese marketing exaggeration..

Xringer · 02-15-13, 05:26 PM

Yeah, at that size, it's likely 30A..

stevehull · 02-15-13, 05:59 PM

Quote:

Originally Posted by Xringer

Hey Steve, I would never try to feed AC neutral anywhere on a coax shield.
That's just too dangerous.
In 1968, I purchased 6 meter rec converter from an old Ham.
It came with a DIY power supply. It was a plain metal box with a transformer on top.
It worked fine, so I never opened the box.. It had a non-polarized AC plug.

After a near disaster, I opened the box and found the transformer was only
6.3vac for the tube's filaments! The 170VDC B+ for the tube plates
was directly rectified right off the grid!!

The neutral side of the plug was the box ground.
The hot line connected to a big diode and a cap.

The day I plugged it in the wrong way, it was snowing and raining.
The hot side was on the outside coax shield. I never noticed anything.

Later I heard on the scanner, 'A power line has fallen on the fences'..
My neighbor told me that there was sparks when he closed the gate.
I then realized, The 6M antenna was on the fence!
I disconnected the converter and opened the box.. Dang!
I ran out and told the power company guys what happened.
They were glad to get out of the weather.
My wife heard on the scanner, "Some ham radio nut had power connected to his fence".
All the fences on the block were connected together. And, all the steel poles
were sitting in wet concrete blocks in the wet ground.

All that ground should have shorted and blown the 15A fuse in the basement.
I went down and checked it the next day. It was blown!
It had been blown before we moved in..
But, some other tenant had placed a penny behind it..

I looked over both basement fuse boxes and found 4 more pennies!

God saves idiots and kids . . . I now know how dangerous it was, but at that time, most everything was non-polarized.

Funny too in developing couintries, they throw a clamp over an overhead line, connect it to a 120 v incandescent bulb and literally ground the other end. If it blows up it is 220. Then then put in a 220 bulb, if it blows then it is 440 . . .

When the "village expert" knows the voltage, he rigs a transformer to step it down to 120 and strings wires to the village. Primitive, but it works

.

Another person (same village) put up an electric fence around his pasture. I knew he was in trouble when he asked me which of the two wires he should plug the "electric fence" wire into . . .

So what is wrong with pennies . . . . .!!

Xringer · 02-15-13, 06:45 PM

Pennies are 3,000 amp fuses!

When we moved in to that apartment in August of 1968, we had a nice GE toaster.
It was a wedding gift. It sat on our big metal sink for 5 years and worked perfectly.

It had a non-polarized AC plug.

In 1973 we moved into our current home. Within a few years,
I talked my wife into one of those newfangled microwave ovens. (300watts)!

After plugging in it's three pronged plug, I put my left hand on the left side
of the GE toaster and pushed it up next to the new Sears microwave.

There was a bright flash as a steel screw head on the oven's cover,
welded itself to side the chrome toaster. The fuse blew within milliseconds..

I broke the toaster off the screw head and took it apart.
One of the AC cable lugs was installed, twisted 90deg to one side..
The terminal screw was nice and tight from the factory.
I re-tightened that screw after correctly positioning the terminal lug
(removing the short to chassis) and we had many more years of toast..

That thing could have killed one us at any time.
Just one hand on a ground, and the other on the toaster.
Didn't even have to be burning the toast.

That new micro wave not only warmed up leftovers, it might have saved a life..

Christ · 02-15-13, 08:22 PM

This is pretty interesting. I never thought of using Coax connections, but I have thought of using RCA's before. Considering the power that twisted pair cabling can handle through RCA connections, including the 60KW I've put through them [audio installations], I imagine they'd work out pretty well.

Keeping an eye on this.

Xringer · 02-15-13, 09:43 PM

Check out RG8 with PL-259 males and SO-239 female chassis-mount connectors.

'N' on top, and PL259 on bottom.. These are crimp. Solder type is better.

Christ · 02-15-13, 09:57 PM

The PL259 looks a bit more 'robust' in the mid pin... am I seeing that right? Seems that would be the better choice if one were to attempt this?

Xringer · 02-15-13, 10:11 PM

Quote:

Originally Posted by Christ

The PL259 looks a bit more 'robust' in the mid pin... am I seeing that right? Seems that would be the better choice if one were to attempt this?

It's not a fragile pin like the 'N' connector uses. Once you learn how to install them,
it's easy to make pretty good connections.
PL-259 Installation Made Easy for RG213 - YouTube

Note: Always remember to slip the screw-on outer shell onto the cable before soldering..
Otherwise you will have to start over..

Christ · 02-15-13, 10:15 PM

For testing purposes, would it be sufficient to use, maybe, some prepared RG-6? I think that's what it is.

I understand that the wire is thin and the shielding is more like aluminum foil, but how well do you think it would fare for short term beta testing type stuff?

02-15-13, 05:05 PM	#11
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	Hey Steve, I would never try to feed AC neutral anywhere on a coax shield. That's just too dangerous. In 1968, I purchased 6 meter rec converter from an old Ham. It came with a DIY power supply. It was a plain metal box with a transformer on top. It worked fine, so I never opened the box.. It had a non-polarized AC plug. After a near disaster, I opened the box and found the transformer was only 6.3vac for the tube's filaments! The 170VDC B+ for the tube plates was directly rectified right off the grid!! The neutral side of the plug was the box ground. The hot line connected to a big diode and a cap. The day I plugged it in the wrong way, it was snowing and raining. The hot side was on the outside coax shield. I never noticed anything. Later I heard on the scanner, 'A power line has fallen on the fences'.. My neighbor told me that there was sparks when he closed the gate. I then realized, The 6M antenna was on the fence! I disconnected the converter and opened the box.. Dang! I ran out and told the power company guys what happened. They were glad to get out of the weather. My wife heard on the scanner, "Some ham radio nut had power connected to his fence". All the fences on the block were connected together. And, all the steel poles were sitting in wet concrete blocks in the wet ground. All that ground should have shorted and blown the 15A fuse in the basement. I went down and checked it the next day. It was blown! It had been blown before we moved in.. But, some other tenant had placed a penny behind it.. I looked over both basement fuse boxes and found 4 more pennies! __________________ My hobby is installing & trying to repair mini-splits EPA 608 Type 1 Technician Certification ~ 5 lbs or less..

02-15-13, 05:26 PM	#13
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	Yeah, at that size, it's likely 30A.. __________________ My hobby is installing & trying to repair mini-splits EPA 608 Type 1 Technician Certification ~ 5 lbs or less..

02-15-13, 06:45 PM	#15
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	Pennies are 3,000 amp fuses! When we moved in to that apartment in August of 1968, we had a nice GE toaster. It was a wedding gift. It sat on our big metal sink for 5 years and worked perfectly. It had a non-polarized AC plug. In 1973 we moved into our current home. Within a few years, I talked my wife into one of those newfangled microwave ovens. (300watts)! After plugging in it's three pronged plug, I put my left hand on the left side of the GE toaster and pushed it up next to the new Sears microwave. There was a bright flash as a steel screw head on the oven's cover, welded itself to side the chrome toaster. The fuse blew within milliseconds.. I broke the toaster off the screw head and took it apart. One of the AC cable lugs was installed, twisted 90deg to one side.. The terminal screw was nice and tight from the factory. I re-tightened that screw after correctly positioning the terminal lug (removing the short to chassis) and we had many more years of toast.. That thing could have killed one us at any time. Just one hand on a ground, and the other on the toaster. Didn't even have to be burning the toast. That new micro wave not only warmed up leftovers, it might have saved a life.. __________________ My hobby is installing & trying to repair mini-splits EPA 608 Type 1 Technician Certification ~ 5 lbs or less..

02-15-13, 09:43 PM	#17
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	Check out RG8 with PL-259 males and SO-239 female chassis-mount connectors. 'N' on top, and PL259 on bottom.. These are crimp. Solder type is better. __________________ My hobby is installing & trying to repair mini-splits EPA 608 Type 1 Technician Certification ~ 5 lbs or less..

02-15-13, 08:22 PM	#16
Christ Apprentice EcoRenovator Join Date: Aug 2009 Posts: 123 Thanks: 14 Thanked 1 Time in 1 Post	This is pretty interesting. I never thought of using Coax connections, but I have thought of using RCA's before. Considering the power that twisted pair cabling can handle through RCA connections, including the 60KW I've put through them [audio installations], I imagine they'd work out pretty well. Keeping an eye on this.

02-15-13, 09:57 PM	#18
Christ Apprentice EcoRenovator Join Date: Aug 2009 Posts: 123 Thanks: 14 Thanked 1 Time in 1 Post	The PL259 looks a bit more 'robust' in the mid pin... am I seeing that right? Seems that would be the better choice if one were to attempt this?

02-15-13, 10:15 PM	#20
Christ Apprentice EcoRenovator Join Date: Aug 2009 Posts: 123 Thanks: 14 Thanked 1 Time in 1 Post	For testing purposes, would it be sufficient to use, maybe, some prepared RG-6? I think that's what it is. I understand that the wire is thin and the shielding is more like aluminum foil, but how well do you think it would fare for short term beta testing type stuff?