Trains causing carriers and heterodynes all over the CB band.

[Shockwave]

It is inverter interference. Very common.
Mike

The interference is similar to the type that switch mode devices like power supplies and inverters make in that it generates many spurs all over the band. It differs because it has a fundamental frequency in the center of its bandwidth that is about 15db stronger that the first adjacent spurs and it's powerful enough to radiate over a mile. It almost looks like the carrier has been modulated by a 40 KHz. audio signal with all of the characteristic side bands.

 

[Staybolt]

R

If you live within a mile or so of any train tracks and you haven't noticed the band filling up with carriers, it's only because Positive Train Control has not be installed in your area yet. The device in question transmits a 27 MHz. signal from an antenna under every train. This signal is only used to power remote receivers on the track that are recording the trains location and other perimeters. This 27 MHz. signal cannot be interfered with since it carries no information and is only a remote power source. The 27 MHz. RF is rectified into DC on the track.

The entire system is in violation of multiple FCC rules that are not only being ignored, but the equipment being used seems to have been carefully designed to CAUSE interference. First, the CB band allows use of remote control devices only on designated RC frequencies. Since this system is using CB to remotely power another device, it is by definition a remote control device and could only be authorized on RC frequencies.

The fundamental frequency this system operates on is channel 13 but it is loaded with spurs that appear every 40 KHz. up and down from channel 13. The first lower spur lands right on channel 9. Unfortunately I've been unable to find any FCC type acceptance information regarding this system. Not even a file number to look up. If you are within a few blocks of any train tracks the spurs are strong enough to extend right into the CW portion of 10 meters!

I wonder how long before every train in the country has a PTC device installed that could never pass any FCC inspection or rules? What's going on here and who ignored every regulation to press these filthy RF generators into service on the air?

Really? I live 500' from a busy NS mainline that IS now 100% PTC and I don't get a whisper out of it.. No issues at all.

 

[Staybolt]

its a local thing in my area.wife and i attended a local hamfest.the president of the local chapter was saying ask him n he would gladly show and explane in detail the test and all.i waited till he wasnt busy.walked up introduced my wife n i ,then said im interested in taking the test.he said im busy dont bother me. He then walked over n started bsing with a few of his friends..
Looked around n a man that WAS a club member said hi to him he snubbed him too. I talked to the snubbed guy n he said his membership expires n its the end of it for that reason.
My wife n i been through some bad stuff,she said no way your gonna be around people like this.kinda got off the ham idea after that. Im ok with my cb radios. I sold my like new kenwood 271 ihad n said its over

That's sad there guy. Sadly a lot of hams are this way and then sit around and whine that nobody wants anything to do with the hobby. Its all because of the shitty attitudes hams have.... I used to be active and one day I had enough and just walked away... Im ok with my CB stuff.

 

[sonoma]

I lived 1/4 mile from a switching station that ran 24 hours a day for 2 years and it drove my radio nuts every time they unhooked cars and then moved them around and rehook them to another engine to leave out. there was always about 200 cars in the lot and the guys were moving them around to hook to another engine for their destination 24 hours a day. I had to forget about a radio for 2 years when I was in Michigan . the noise from their switching system and radios would bleed all over my radio no matter what channel I was on.

 

[Rwb]

I lived 1/4 mile from a switching station that ran 24 hours a day for 2 years and it drove my radio nuts every time they unhooked cars and then moved them around and rehook them to another engine to leave out. there was always about 200 cars in the lot and the guys were moving them around to hook to another engine for their destination 24 hours a day. I had to forget about a radio for 2 years when I was in Michigan . the noise from their switching system and radios would bleed all over my radio no matter what channel I was on.

that kinda voilates fcc rules dont it?

 

[Rwb]

That's sad there guy. Sadly a lot of hams are this way and then sit around and whine that nobody wants anything to do with the hobby. Its all because of the shitty attitudes hams have.... I used to be active and one day I had enough and just walked away... Im ok with my CB stuff.

yep.they act arrogant,not all but enough it ruins the idea for me..what realy boils my water is how so many worked cb n look down on anybody on cb now.complains about us on chicken band.i will stick to my cb radios and enjoy them

 

[Shockwave]

that kinda voilates fcc rules dont it?

Any generated signal that can wipe out an entire band from a mile away is a blatant violation of FCC rules. It's also a violation to place thousands of "high powered HF signals" on the air in the USA without those devices being FCC certified. Either the device has to demonstrate that it is low powered enough to comply with Part 15 and does not radiate harmful interference or it must be certified if it exceeds those power and range limits.

The level of interference and "high powered HF" description, proves beyond any doubt that we are dealing with something far more powerful than part 15 equipment. The requirement for certification beyond that power level suggests that no competent certification ever took place. Any competent engineer could easily spot this problem from a mile away. Literally! So now the FCC is in a catch 22. Do they admit incompetence in that they never tested or that they failed to see the obvious during testing?

Either way, someone would be responsible for allowing millions of dollars of defective safety equipment to be constructed and installed nationwide. Someone could have even been paid to "look the other way". After all, it is only 11 meters. Imagine the outcry if it were another band? I'm unable to see any explanation other than money or blackmail that could get this one through Part 15 inspection much less full certification, but I'm open to ideas? I'm taking bets that this screw up will turn out to be big enough that it never gets owned or fixed.

 

[Shockwave]

R


Really? I live 500' from a busy NS mainline that IS now 100% PTC and I don't get a whisper out of it.. No issues at all.

Unfortunately at 500 feet, it's just a matter of time before your ears get clogged on this band too. Both PTC and ATP are part of the new nationwide safety standards. Positive Train Control was the first mandate and uses 220 MHz. Advanced Train Positioning uses a high power (broadband) 27 MHz. signal and it's headed your way. Just look at the confirmations coming from others across the country in the last few days. Over the next year, the gaps in between will be filling in with complaints.

It started slow here in Connecticut over 5 years ago and took a year before it became enough of a nuisance that I put effort into tracking it down. Today it's so bad that the heterodynes from multiple trains are somehow causing bleedover on top of the 40 KHz. spurs, so it's covering the entire band with noise. Only my best receiver is still able to find a few slivers of spectrum immune from this interference but that's with the IF filter in the narrowest position and crappy fidelity as a result.

 

[Rwb]

Any generated signal that can wipe out an entire band from a mile away is a blatant violation of FCC rules. It's also a violation to place thousands of "high powered HF signals" on the air in the USA without those devices being FCC certified. Either the device has to demonstrate that it is low powered enough to comply with Part 15 and does not radiate harmful interference or it must be certified if it exceeds those power and range limits.

The level of interference and "high powered HF" description, proves beyond any doubt that we are dealing with something far more powerful than part 15 equipment. The requirement for certification beyond that power level suggests that no competent certification ever took place. Any competent engineer could easily spot this problem from a mile away. Literally! So now the FCC is in a catch 22. Do they admit incompetence in that they never tested or that they failed to see the obvious during testing?

Either way, someone would be responsible for allowing millions of dollars of defective safety equipment to be constructed and installed nationwide. Someone could have even been paid to "look the other way". After all, it is only 11 meters. Imagine the outcry if it were another band? I'm unable to see any explanation other than money or blackmail that could get this one through Part 15 inspection much less full certification, but I'm open to ideas? I'm taking bets that this screw up will turn out to be big enough that it never gets owned or fixed.

im betting your correct,but i wonder if it was on ham bands how much the ham operators would pi$$ n moan about it?

 

[Slowmover]

im betting your correct,but i wonder if it was on ham bands how much the ham operators would pi$$ n moan about it?

Dude, that’s gonna be a, “Mr Smith Goes to Washington”, moment. Congressman “HAM-bone” rallies the public over 27-MHz and thwacks the railway Goliath.

And it’s only the start. Wait’ll he gets his teeth into the Pentagon for overloading Guam and causing it to tip over.

 

[338_MtRushmore]

I'm pretty sure that any pissing match about 11m interference would end with nothing but revoking the whole band. With cell and gmrs and others, CB probably isn't very high on the give a darn list. They gave it to us, and they can take it away.

 

[Shockwave]

The more I think about this problem, the more I realize it would be difficult to recreate without having intention to do so. Just about any engineer would be inclined to start a single frequency HF generator from a stable crystal base. These units wobble around plus or minus a few KHz. and create annoying heterodynes as a result. It almost looks like someone was being a wise guy and used an unstable, crystal calibrator as the frequency source for this RF generator. Remember this signal had very few requirements to be functional. It only has to supply enough RF energy to power the remote transponder on the track. So long as the power is sufficient and the frequency is close enough to magnetically couple, it works for them.

 

[Slowmover]

The more I think about this problem, the more I realize it would be difficult to recreate without having intention to do so. Just about any engineer would be inclined to start a single frequency HF generator from a stable crystal base. These units wobble around plus or minus a few KHz. and create annoying heterodynes as a result. It almost looks like someone was being a wise guy and used an unstable, crystal calibrator as the frequency source for this RF generator. Remember this signal had very few requirements to be functional. It only has to supply enough RF energy to power the remote transponder on the track. So long as the power is sufficient and the frequency is close enough to magnetically couple, it works for them.

So this isn’t an outgrowth of the vaunted US electronic warfare community. You’re saying.

Nothing but the best for our boys.

.

 

[Slowmover]

I'm pretty sure that any pissing match about 11m interference would end with nothing but revoking the whole band. With cell and gmrs and others, CB probably isn't very high on the give a darn list. They gave it to us, and they can take it away.

Three million truck drivers might disagree with that. The most common job description for men in this country.

.

 

[Shockwave]

I'm pretty sure that any pissing match about 11m interference would end with nothing but revoking the whole band. With cell and gmrs and others, CB probably isn't very high on the give a darn list. They gave it to us, and they can take it away.

That's one thing that will never happen because the band has no resale value like 220 or analog TV spectrum. They don't do what's right, they do what's profitable.