View Full Version : carbon monoxide

03-18-2017, 12:35 AM
Everytime I fire up my Heathkit SB 201 my carbon monoxide alarm goes off in my shack. Any idea why and how to cure it!!

03-18-2017, 01:03 AM
Stray RF. Buy a Low Pass Filter, or an isolating balun, and place it between radio and meter/amp/antenna. Whichever you have or buy. RF Limited makes a decent LPF. The DF3000. Cost is about $45. Dr. Dipole makes a nice 1:1 balun. Or am isolating balun. Place the balun at the feedpoint of the antenna.
That or you can try some snap on ferrite chokes at the carbon monoxide unit. Snap on chokes to the wires going to the unit. Either way should work, but the Low Pass Filter is the way to go truly.
That and use good coax as well. Good double shielded coax.
And last but not least, a balun at the feedpoint of the antenna.
All of the above will help eliminate any stray RF, as well as good grounding of your antenna system and also having he antenna up as high as possible and away from the house if possible. It could also be your radio. If it's been hot rodded it may be throwing off some harmonics. Or spurious emissions.
At any rate, I would try making sure all your coax connections are good, and tight as well. Make sure there aren't any bad jumpers or loose connections. Then I would get a Low Pass Filter. There are other companies that make good ones. Drake, Bencher. And some others. Stay away from the MFJ ones. I heard they suck.
Anyways. Hope the text wall explains its and helps to get it eliminated for you. Have a good one!!

03-19-2017, 06:23 PM
...Take the battery out of the carbon monoxide alarm, problem solved...

03-20-2017, 09:05 PM
That works too JJD. Every time!![emoji106][emoji106]

03-22-2017, 11:51 PM
I forgot to mention that the RF is also getting into my phone line and computer speakers!!

03-23-2017, 01:11 AM
Then you have some definitely have some RFI/TVI issues. Try a 1:1 isolating balun, a Low Pass Filter and/ or some ferrite snap on chokes at each of the affected pieces of equipment. I would do all three to be safe. Get a good 1:1 isolating balun. Dr Dipole makes some good ones. And there are many one ebay for not much. Next, a good Low Pass Filter. RF Limited makes one, the DF3000, it works well. Also Bencher, Drake, and a few others make a good Low Pass Filter. Stay away from the MFJ stuff though. It's junk so I've heard. Also adding some snap on ferrite chokes to the lines of the affected equipment may help. Getting as many wraps through the ferrite choke as possible. Hope some of this helps. Also read up on how to combat RFI/TVI issues. Good luck and let us know how you make out!!

03-23-2017, 05:04 PM
Farrite snap on chokes work good on speakers...My base radio with the Amp on was getting into my daughters headphones, so I stuck a farrite choke on the cord of her headphones at the plug where it plugs into her computer, and case-closed... Just need a choke big enough where you can make at least one loop of the cord threw it at the plug end...would probably work on phone cords too...

Never had much luck with the low-pass filters.

04-09-2017, 09:07 AM
if your radio sending a over modulated signal to the amp the the amp will splatter even if the amp itself is not being over driven beyond it's clean output ability .... dirty in dirty out . what radio are you driving it with and how much power are you putting into the amp and how much are you getting out ?