Radio interference on lights when TX'ing

Hey guys,

Had an issue last night when transmitting. I've recently installed lights with an STL remote switch fob. Lights work perfectly on the pattern I selected for them (w/ momentary switch in key fob). When I keyed up on my TK7180 the pattern changed on the lights to an odd steady burn / slow flash pattern. My antenna cable is on the opposite side of the car from the wiring of the lights. My TK7180 has a remote head kit and the wiring for that is close to the wiring for the lights. Could that be my issue? The only other thing I can think is that the relay for the lights and the relay for the radio are on the same ground.

I don't really want to go outside and pull things apart until I know what's going on, its a beautiful 12 degrees out today.

Please no unnecessary comments about STL. Saying "Buy whelen used" doesn't help anyone.

Thanks!
 

Sparky_911

Member
Gold Supporter
Try separating the radio and relay grounds first. Could be back feeding to the lights when you TX. Ground the relay at least a foot or more from the radio components.
The antenna wire should be shielded enough that it wouldn't cause interference but the antenna itself could.
 

Jarred J.

Archive Expert
Silver Supporter
You dont want to hear it cause it's the truth. The fob probably isn't shielded for RF and the strongest signal wins...

Now on a more curious natured question what is the fobs.tx freq and what radio service are you using.. insert smiley face here cause the website smileys aren't working...
 

Nolines

Silver Supporter
There's always the tried and true : ) but I can't wait to hear this myself cause I have that wireless fob myself and haven't hooked it up yet.
 
"STL"? "TK7180"?
As a ham radioperator I may be able to help if I knew.
Thank you.
 

Jarred J.

Archive Expert
Silver Supporter
Stl is speed tech lights.
Tk7180 is one of those nasty Kenwood's hams don't use.. lol

73
 

d119

Member
Nice one, Jarred.

Get some various ferrite beads and put the cables for the key fob interface and all lighting related cables through the ferrites. Do some homework on how to install them. This will strip (most) of the RF off of those cables and likely solve your problem.

We've had issues with marker lights on some of our LRVs turning off when the radio is keyed. We know it's not the radio that's at fault. We put ferrites on the lamp power leads and that solved the problem.

NOTE: Not all ferrite beads are created equal, and you may have to buy a "kit" of multiple types and experiment with them until you find what works. I have a feeling you'll have success with it though..
 

Jarred J.

Archive Expert
Silver Supporter
@Nolines Hams have a thing about kenwoods vs icom vs yaesu like everybody else has against ford vs dodge vs chevy... they all have their cults
 

Nolines

Silver Supporter
Like motorola vs harris vs bendix etc etc etc.

Used to be motorola was king but the new setup is so garbage and expensive.
 

d119

Member
Hams don't understand the concept of not having a VFO, let alone having to use a computer to program things.

They also don't understand the ruggedness of a commercial radio vs. an amateur radio, be it Kenwood, Icom, Yaesu or Barfalong.

And yes, I'm a ham. A real ham, not an appliance operator with a callsign.
 

kilodelta97

Newbie
Thread Starter
You dont want to hear it cause it's the truth. The fob probably isn't shielded for RF and the strongest signal wins...

Now on a more curious natured question what is the fobs.tx freq and what radio service are you using.. insert smiley face here cause the website smileys aren't working...

I know it's the truth... I actually went that route with my last car, bought all used Whelen and outfitted it like that. For some reason I wanted to try the STL, if they crapped the bed it wouldn't be a huge monetary loss.

In my area we use VHF in the public safety range, 150mHz to 160mHz approx. My first thought was that the remote was TX'ing somewhere in that range, but after a conversation with someone at STL (very helpful but not very knowledgeable), he couldn't tell me what the RF that the fob used

Nice one, Jarred.

Get some various ferrite beads and put the cables for the key fob interface and all lighting related cables through the ferrites. Do some homework on how to install them. This will strip (most) of the RF off of those cables and likely solve your problem.

We've had issues with marker lights on some of our LRVs turning off when the radio is keyed. We know it's not the radio that's at fault. We put ferrites on the lamp power leads and that solved the problem.

NOTE: Not all ferrite beads are created equal, and you may have to buy a "kit" of multiple types and experiment with them until you find what works. I have a feeling you'll have success with it though..

So throw these ferrites on all the power wires for the lights at the spots where they connect to the fob's receiver? Thanks for the help, I figured it would be some kind of fix like this.
 

d119

Member
So throw these ferrites on all the power wires for the lights at the spots where they connect to the fob's receiver? Thanks for the help, I figured it would be some kind of fix like this.
Correct. And of course, remember that not all ferrites are created equal, so if at first you don't succeed, experiment with not only placement of the ferrites, but also different types of ferrites. Usually you just wrap the affected cable through the ferrite a couple of times and clamp it on. The ferrite should not move around if it's got a couple of cable wraps through it. Then it snaps together.

Example:

1611762155772.png
 

kilodelta97

Newbie
Thread Starter
I know it's the truth... I actually went that route with my last car, bought all used Whelen and outfitted it like that. For some reason I wanted to try the STL, if they crapped the bed it wouldn't be a huge monetary loss.

In my area we use VHF in the public safety range, 150mHz to 160mHz approx. My first thought was that the remote was TX'ing somewhere in that range, but after a conversation with someone at STL (very helpful but not very knowledgeable), he couldn't tell me what the RF that the fob used



So throw these ferrites on all the power wires for the lights at the spots where they connect to the fob's receiver? Thanks for the help, I figured it would be some kind of fix like this.

Also, I separated the grounds for the relays. Worked at first and I was happy because i thought it solved it. Next time I needed to used both at the same time (later that day), wouldn't you believe that it did it again.
 

kilodelta97

Newbie
Thread Starter
Correct. And of course, remember that not all ferrites are created equal, so if at first you don't succeed, experiment with not only placement of the ferrites, but also different types of ferrites. Usually you just wrap the affected cable through the ferrite a couple of times and clamp it on. The ferrite should not move around if it's got a couple of cable wraps through it. Then it snaps together.

Example:

View attachment 227860
That's an easy enough fix. I'm going to try this out and I'll report back. STL, although cheap, is pretty popular around here. I'm sure I'm not the only one that'll have this issue so when I find a fix I'll throw it in this thread for those behind me.
 

Jarred J.

Archive Expert
Silver Supporter
If a device is transmitting in the US it has to have a Lic to do so. Inside the key fob or somewhere should be a fcc lic # google it and you should see it's permitted freq. If not find someone with a multi band freq counter or get a cheap one off Amazon...
 

d119

Member
If a device is transmitting in the US it has to have a Lic to do so. Inside the key fob or somewhere should be a fcc lic # google it and you should see it's permitted freq. If not find someone with a multi band freq counter or get a cheap one off Amazon...
Usually these are "Part 15" devices that are licensed by rule, rather than individually. Looking up the operating frequency (which is probably 315MHz or 433MHz) really isn't going to do anything to mitigate the interference.

I'm sure he will have success with the ferrites, I'm certain the wiring is acting as an antenna.
 

Lt.214

Premium Member
Silver Supporter
I know it's the truth... I actually went that route with my last car, bought all used Whelen and outfitted it like that. For some reason I wanted to try the STL, if they crapped the bed it wouldn't be a huge monetary loss.

In my area we use VHF in the public safety range, 150mHz to 160mHz approx. My first thought was that the remote was TX'ing somewhere in that range, but after a conversation with someone at STL (very helpful but not very knowledgeable), he couldn't tell me what the RF that the fob used



So throw these ferrites on all the power wires for the lights at the spots where they connect to the fob's receiver? Thanks for the help, I figured it would be some kind of fix like this.
Just a quick question, how much power (in watts) are you transmitting with the kenwood, and how close is the antenna to the lights in question. If your running 50watts and the antenna is in close proximity to the lights, it may be the source of the issue. If possible on your radio, drop to a low power setting.

I am also a ham and have had issues with high power VHF cause strange things to happen. It's all energy in the end and can have adverse effects on other electric components.

Chris
 

kilodelta97

Newbie
Thread Starter
Just a quick question, how much power (in watts) are you transmitting with the kenwood, and how close is the antenna to the lights in question. If your running 50watts and the antenna is in close proximity to the lights, it may be the source of the issue. If possible on your radio, drop to a low power setting.

I am also a ham and have had issues with high power VHF cause strange things to happen. It's all energy in the end and can have adverse effects on other electric components.

Chris
I'm transmitting at 50 watts. I might try and switch to low power in the morning and see how that works. I'm really only using it for repeaters which are realitively close so hitting those with low power shouldn't be hard. The antenna is 3ish feet from the closest light head. The actual antenna coax is no where near the lighting or wire for the lights.

Also a Ham here- I hate to admit that I haven't actually used my license since getting it.
 

kilodelta97

Newbie
Thread Starter
Ordered the ferittes off Amazon. Prime is slow in my area so it'll be a couple days. in the meantime, I'll let you all know how changing the power works
 

kilodelta97

Newbie
Thread Starter
Sooooo! Its been about two months. I was ready to pull my hair out. Tore into every bit of wiring and tried different size ferrites all over the wires. It worked for the front lights. The rear, not so much. My guess is that due to the proximity of the antenna, the actual light head was being affected in the back, rather than the wiring. Turns out STL's products are not sheilded well enough, as someone suggested.

I fixed the issue with the rear lights by switching my radio over to low power on Tx, and then adjusting low power to around 15 watts. It's enough to break squelch on all the repeaters but not enough to affect the rear light's operation.

Last time with STLs. Next time, going back to Whelen.
 

Lt.214

Premium Member
Silver Supporter
Glad you found the issue but sucks it's the lack of shielding. There is something to be said for sticking with the main stream brands.

Chris
 

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