For many years my wife's treadmill caused strong interference on 160 meters when it was in use, and yesterday I was able to completely eliminate the RFI using a combination of two different filters (
Treadmill combination filter update. Today I replaced the 10 amp commercial filter with the 20 amp version of the filter, and the results are similar. Below are a few measurements on 160 meters and 8
Don, FWIW, today, W5UJE and I dealt with a treadmill problem similar to yours by installing a commercial line filter between the line and the treadmill electronics. A Corcom/TE Connectivity 20VR1 fil
Hi Brad, Great to hear you had similar results. The 20VR1 and the 20DRGG5 filter appear to be of very similar design (two stage filters, and component values not vastly different). The 20VR1 looks to
Don, You make a good point about the difference between our definition of CM noise and the definition implied in Part 15. If the external torroid made a difference for you, then it's important and wo
are talking about current that is flowing in the same direction on three conductors." In my case the additional Toroid core choke had a very noticeable impact, and I now can't tell when the treadmill
Yes. Remember, the test is conducted with the EUT taped to a grounded copper plate on the table top. The LISN is taped to a grounded plate on the floor of the test chamber. This is not how we set up
On Tue,1/27/2015 4:08 PM, Tom W8JI wrote: The flaw in this system is that differential voltages between current carrying wires are not measured, and anything on the safety ground isn't measured. Nois
Exactly. The commercial filter addresses only differential mode. The ferrite choke is necessary to suppress what we (and Part 15) call common mode. Several years ago, I put some good quality line fil
Jim, No question that a separate filter for the green wire can make a difference when there's RF current on that lead. But I'd wait to add the extra filter until I was sure it was needed. The case ye
On Wed,1/28/2015 8:34 AM, Brad Rehm wrote: I've never looked closely at the problem, but I wonder how the 31-mix cores behave in the presence of high-current, 20 kHz fundamental frequency pulses that
Nice to hear all the comments, recommendations, and indeed some success stories here. I too have a treadmill problem. Although I'm blessed with a radio-friendly spouse who always asks before she star
A deep "4 inch box"? Add extension rings if necessary? Ganged outlet boxes? http://www.mcmaster.com/#standard-outlet-boxes/=vohae8 I know I've seen on the web somewhere, a Grow-Light filter with 3 bi
If you're trying to find a suitable box to mount *in the wall* that will fit two duplex receptacles and some filters, try a 4-11 box (4-11/16" square) that is 2-1/8" deep (this is a standard size). Y
On 1/29/2015 10:23 AM, Carl Clawson wrote: Nice to hear all the comments, recommendations, and indeed some success stories here. I too have a treadmill problem. Although I'm blessed with a radio-frie
Ganged outlet boxes are no longer a good option. In years past, they were fairly beefy. Modern ones are lighter gauge steel and too flimsy to hold together outside of a wall (and too flimsy in the wa
Slide #6 in http://nccc.cc/pdf/CQP-RFI2013-2.pdf shows how I mounted a 20A line filter in deep multi-gang boxes. Each box is sized to hold a single duplex outlet or switch. I've forgotten the correct
Ferrites on the cord don't work on 160 meters if they are of the single turn class: easy to use, but ineffective, clamp on beads. What does have a chance of working is 15 or so turns on a 2.4 inch O.
Bypassing is usually much more effective than simply adding series impedances. Sometimes bypassing alone is more than enough. 90% of the time when I clean up an offshore SMPS for Ham use, it is just
This snide remark ignores the fact that it is generally not practical (nor is it good politics) to go inside your neighbor's equipment to add bypass capacitors. Nor is it practical to open up a wall