Spurious RF emissions?

[WRTC928]

I don't want to ask this question in an amateur radio forum because I'm afraid I couldn't get a straight answer, so I'll try it here. If I understand correctly, any "spurious emissions" will not be retransmitted by a repeater. It will pick up the strongest part of the signal and retransmit that on a different frequency. So, my question is, how much harm can spurious emissions from a 5 watt HT actually do? Yes, I understand about the possibility of creating interference in a frequency allocated to public safety or commercial radio, but realistically, how likely is that? Hams tend to think of these things from the standpoint of tall antennas and high wattage, and you likely could muck up stuff with a 50' antenna and 1,000 watts, but a 5 or even 10 watt HT doesn't seem to have much potential to cause trouble.

Do commercial LMR and public safety radios have filters to eliminate the "fuzz" created by a low-power harmonic? I assume the technology exists, and if I were building a $1,200 radio for a police department, I'd certainly include it. I'm not arguing that a "cleaner" signal isn't better and more desirable, but I suspect the "dirty" signal from a cheap HT isn't going to actually matter to anyone.

I already know @OffRoaderX's opinion  but I'm curious what the rest of you think.

[tcp2525]

3 hours ago, Jaay said:

IF you learn how to use a RF Analyzer, then you'd understand how to interpret the figures. Also Nobody's Sad, just Smarter .

While it's a good question and one that can be fun to ponder upon, I let the people that get paid to worry about these things earn their salary. Of course you'll always have your traditional forum creatures with way too much time on their hands worry about splitting hairs that nobody cares about.

[OffRoaderX]

23 minutes ago, WRTC928 said:

I already know @OffRoaderX's opinion

I'm going to squirt some opinion anyway, even though you already know it.

23 minutes ago, WRTC928 said:

how much harm can spurious emissions from a 5 watt HT actually do? ....  how likely is that? 

The likelyhood is a fraction higher than zero - it's not absolute zero, but very close to zero..   Its funny how "some people" will proclaim that my cheap little CCR can't talk more than a few hundred yards, yet, one minute later they will proclaim that the same radio's spurious RF emissions will bring down a 747 at 38,000 feet or jam an entire police department's communications system from 5 miles away.
 

23 minutes ago, WRTC928 said:

Do commercial LMR and public safety radios have filters to eliminate the "fuzz" created by a low-power harmonic?

YES!  at least, some do.   I have seen this myself many times when comparing my XTL5000 radios in both my Jeeps to cheap radios in Jeeps just a couple of feet away - it actually happened yesterday.  Our friend's radio was completely unusable when we were about 1/4 mile from a big antenna tower site, and the XTLs in my and my wife's Jeeps were silent.  and this has happened many times.  It is doubtful that any decent LMR radio would ever be affected by the spurious emissions from a 5w HT miles away.

[WRUE951]

Spurou's emissions from baby room monitors have known to drive some radio enthusiasts nuts so i can imagine that spurious emmissions from a 5 Watt HT can do the same.  However it's unlikely an HT will be in continuous XTMT mode so i dont think the damage would be that severed.    

[LeoG]

Usually that not SE but on the same frequency in a constant transmit mode.

[Socalgmrs]

2 hours ago, OffRoaderX said:

2 hours ago, WRTC928 said:

 

The likelyhood is a fraction higher than zero - it's not absolute zero, but very close to zero..   Its funny how "some people" will proclaim that my cheap little CCR can't talk more than a few hundred yards, yet, one minute later they will proclaim that the same radio's spurious RF emissions will bring down a 747 at 38,000 feet or jam an entire police department's communications system from 5 miles away.

OMG. The stars have aligned.  I TOTALLY AGREE. spurious emissions is not something any one really needs to worry about.  Atleast not from a ccr 2-5w ht 

[Jaay]

47 minutes ago, Socalgmrs said:

OMG. The stars have aligned.  I TOTALLY AGREE. spurious emissions is not something any one really needs to worry about.  Atleast not from a ccr 2-5w ht 

BEHAVE YOURSELF, or YOUR stars will Never align !!  !!  DO some research !!  IF you have secondary harmomics above the the 40 db max then that's LESS power being transmitted on your Primary frequency !!

[WRTC928]

2 hours ago, OffRoaderX said:

Its funny how "some people" will proclaim that my cheap little CCR can't talk more than a few hundred yards, yet, one minute later they will proclaim that the same radio's spurious RF emissions will bring down a 747 at 38,000 feet or jam an entire police department's communications system from 5 miles away.

Yeah, it can't really be both, can it? 

[WRTC928]

1 hour ago, WRUE951 said:

Spurou's emissions from baby room monitors have known to drive some radio enthusiasts nuts so i can imagine that spurious emmissions from a 5 Watt HT can do the same.  However it's unlikely an HT will be in continuous XTMT mode so i dont think the damage would be that severed.    

Even at that, it's just an annoyance, no actual harm done. And as you say, you'd have to pretty much be talking non-stop to matter much to anyone. It would be so weak that likely you could adjust the squelch to get rid of it. As far as interfering with transmitting, I'll wager if that if I were receiving interference due to a harmonic from a 5-10 watt radio, I could just punch my power up to 50 watts and step on them. 

[WRYZ926]

I have seen spurious emissions cause cheap appliances and lights turn on and off. That can be fun if it happens to be your neighbor's stuff that is affected.

Baby monitors can be annoying at times from the interference they can cause.

And it's always fun to mess with neighbors that have scanners that they leave on all of the time that are set to scan all frequencies. Running digital modes on the HF bands makes some obnoxious noses on scanners.

[tcp2525]

Simple answer is if the transmitting radio is FCC type accept you can be assured that the radio tested and its design has passed basic tests for such emissions. As for low powered transmissions, they can be just as harmful as the high powered ones if it is in close proximity of the receiving device. Some implanted medical device can be effected.

On a side note: If your neighbor has her Lush inserted and turned on, spurious emissions can be loads of fun. 

[OffRoaderX]

4 minutes ago, tcp2525 said:

As for low powered transmissions, they can be just as harmful as the high powered ones if it is in close proximity of the receiving device. Some implanted medical device can be effected

Can you point us to an example of that ever being an issue.. for anyone.. ever?  Even just once?

[tcp2525]

16 minutes ago, OffRoaderX said:

Can you point us to an example of that ever being an issue.. for anyone.. ever?  Even just once?

Hey, you're a smart chap and you know Google is your friend. While I hate doing research for others I'll do it for you since I watched one of your YouTube videos and thought you were funny. Just cut and paste "are pacemakers affected by spurious rf emissions" and you'll find what you seek. The short answer is "most" aren't affected, but you don't want to be that one person that it does. There are also some other good reads on the topic.

[OffRoaderX]

42 minutes ago, tcp2525 said:

Hey, you're a smart chap and you know Google is your friend

Fair enough - but the question was "has anyone ever been affected" - not 'is it, or was it ever possible' - BUT,  I did as you suggested, and as you can see below, the answer to my question is "it has never happened" - OR it has happened so few times there is no record found of it today.

[tcp2525]

6 minutes ago, OffRoaderX said:

Fair enough - but the question was "has anyone ever been affected" - not 'is it, or was it ever possible' - BUT,  I did as you suggested, and as you can see below, the answer to my question is "it has never happened" - OR it has happened so few times there is no record found of it today.

The point is it is uncommon, but it is a possibility that they are concerned about. Do they even know how to diagnose an issue of a pacemaker that was affected by RF? Bottom line, it's possible, but you might have a better chance of winning the Powerball jackpot. Here's on I cherry picked.

Yes, pacemakers can be affected by spurious radio frequency (RF) emissions, but modern pacemakers are generally well-shielded, and interference is uncommon. 

 

Here's a more detailed explanation:

• Pacemakers and Electromagnetic Interference (EMI):

  Pacemakers are susceptible to electromagnetic interference (EMI) from various sources, including radio frequencies. 

   
• Potential Effects of EMI:

  In the unlikely event of EMI, a pacemaker could experience:

  • Stopping or irregular pacing: The pacemaker might stop delivering the stimulating pulses that regulate the heart's rhythm or deliver them erratically. 
     
  • Ignoring the heart's rhythm: The pacemaker might ignore the heart's natural rhythm and deliver pulses at a fixed rate. 
     
  • Asynchronous pacing: Some pacemakers incorporate protective algorithms that cause a temporary reversion to asynchronous pacing in response to prolonged inhibition from spurious signals. 
     
• Modern Pacemakers and Shielding:

  Modern pacemakers have improved shielding and protective algorithms to minimize the risk of EMI. 

   
• Sources of EMI:

  • Radiofrequency sources: Cell phones, radio transmitters, and other devices that emit radio waves can potentially cause EMI. 
     
  • Magnetic fields: Strong magnetic fields from certain devices or medical procedures (like MRI) can also interfere with pacemakers. 
     
• Interrogation Telemetry:

  Interference with interrogation telemetry (the process of reading data from the pacemaker) may still occur, especially with older pacemakers. 

   
• 5G Networks:

  The risk of EMI between modern smartphones connected with 5G networks and pacemakers is considered low. 

   
• Ionizing Radiation:

  Repeated exposure to ionizing radiation can alter electromagnetic components of cardiac pacemakers, leading to transient or permanent damage. 

   
• Risk Assessment:

  An individual risk assessment is often necessary after pacemaker implantation, a change of its generator, or major modification of its programming settings. 

   
• Avoiding Interference:

  • Maintain a safe distance from strong electromagnetic sources. 
     
  • Be aware of potential interference from devices like cell phones, metal detectors, and certain medical equipment.

[TDM827]

Oh Boy. I think I know where this thread is headed.........

 

[LeoG]

Well you get the sad hams complaining about radios that do -58dB when the upper limit is -60dB.  Good chance that -40dB isn't going to affect much.

[WRUE951]

Oh Boy, this is turning into............

 

[WRUU653]

7 hours ago, WRUE951 said:

Spurou's emissions from baby room monitors have known to drive some radio enthusiasts nuts so i can imagine that spurious emmissions from a 5 Watt HT can do the same.  However it's unlikely an HT will be in continuous XTMT mode so i dont think the damage would be that severed.    

I have seen where baby monitors on the same frequency have caused issues with GMRS repeaters but I have yet to see anything related to spurious emissions causing such problems. I’m not saying it couldn’t. I just haven’t seen evidence of it though. 

[Hoppyjr]

In reading threads here I’m left with the opinion that some of you guys have never seen a woman naked.

[LeoG]

Didn't know Spurtious Emissions caused woman to be naked.  Good to know.

[TerriKennedy]

1 hour ago, tcp2525 said:

 

• Ionizing Radiation:

  Repeated exposure to ionizing radiation can alter electromagnetic components of cardiac pacemakers, leading to transient or permanent damage. 

In the 1980's I was exposed to an unshielded Cobalt-60 source. I got the heck out of there quickly and called the appropriate people who came ASAP, put it in a cask, and took it away. I'm still kicking at age 66, though some people might say that explains a number of things about me. I never planned on having kids, anyway.

I describe it as "You know it's going to be a bad day when you can sense the ozone forming in your mouth". Sue and  I were watching HBO's Chernobyl mini-series, and in the first episode one of the firefighters says "Why does it taste like metal?" which is probably the same thing.

[TDM827]

35 minutes ago, LeoG said:

Didn't know Spurtious Emissions caused woman to be naked.  Good to know.

Just the opposite. Naked women cause Spurious Emissions.  

[TerriKennedy]

9 hours ago, WRTC928 said:

I don't want to ask this question in an amateur radio forum because I'm afraid I couldn't get a straight answer, so I'll try it here. If I understand correctly, any "spurious emissions" will not be retransmitted by a repeater. It will pick up the strongest part of the signal and retransmit that on a different frequency. So, my question is, how much harm can spurious emissions from a 5 watt HT actually do? Yes, I understand about the possibility of creating interference in a frequency allocated to public safety or commercial radio, but realistically, how likely is that? Hams tend to think of these things from the standpoint of tall antennas and high wattage, and you likely could muck up stuff with a 50' antenna and 1,000 watts, but a 5 or even 10 watt HT doesn't seem to have much potential to cause trouble.

The single-chip RF chips in radios like the ones from Baofeng are going to produce harmonics that are 2x the main frequency (and other multiples). Those are so far out-of-band that no GMRS repeater is even going to "hear" them, let alone act on them.

Early Baofeng (and other models) used to have terrible harmonics. Their designs have gotten much better. There are people with TinySA's (an amazing piece of design - I'm not knocking it) but who cable them up through an attenuator directly to the radio's antenna connector. That is not the FCC's prescribed test methodology, so it's comparing apples and turtles (not even oranges).

I can explain why some tri-band radios appear "dirty" on 136-174 direct-connect test, but since this is a GMRS group that isn't relevant here.

[LeoG]

Sounds like it works both ways.

[TerriKennedy]

3 hours ago, tcp2525 said:

On a side note: If your neighbor has her Lush inserted and turned on, spurious emissions can be loads of fun. 

I'll let you in on a secret - if a Lovense toy is turned on but a) isn't connected to a controlling Bluetooth phone / etc. and b) doesn't have a password set (no password is the default and they don't explain why setting one is a good idea), they're discoverable via BLE (they will all be  named "LVS", the firmware version, and the short product code for the device). Get a BLE scanner app for your phone and you'd be surprised how many of these are around and broadcasting.

Since they're broadcasting, it's OK to monitor them with a BLE app. Installing the Lovense app and actually connecting to one of them would most definitely NOT be OK.