On Fri,2/26/2016 6:20 PM, Lionel Booth wrote:
Hi Jim,
Yep, I mounted the Delta inside of the enclosure with the electronics
and the motor. The PWM controller I think is the source of the noise.
I had 30 over noise in 5 -10 kHz wide every 15 to 30 kHz ( this may
be off a bit, it's been a while) from 40 meters through 12 meters.
Since the treadmill was in use during the day I didn't look on 80 or
160 but suppose it was terrible.
Can you look at 160 and 80? I think that's where David's problem is.
At first I tried clamp on Palomar chokes on the half inch power cable.
Those are not "Palomar" chokes, they are Fair-Rite VHF clamp-ons that
Ralomar resells (and at obscene markups).
At six chokes, one pass, 43 mix, I found almost no improvement.
Clearly not enough impedance.
No surprise -- those are NOT common mode chokes below 50 MHz! They are
VHF chokes. I suggest that you study k9yc.com/RFI-Ham.pdf
The Delta took the interference down below my local noise level. The
cost of the big clamp ons or toroids quickly exceeds the cost of the
delta.
Of course -- you didn't understand the technique, so you bought the
wrong parts and used them incorrectly.
I did try winding a choke and putting inside the enclosure on the ac
line.
How many turns? What was the core?
This helped but not enough. I seem to recall the delta is a balanced
pi section filter rated at 20 amps: the circuit is on a 20 amp CB.
Installed the way you did it, the Delta should work pretty well.
73, Jim K9YC
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