[HiDARG-MEMBERS] Ferrite chokes

[Randy Tomer]

Found the info I was looking for:  Mouser part # 623-2631626402.  1-3/8"
hole, 2-3/8" outside diameter.

Mouser Electronics,  Mouser.com

73, Randy

On Thu, Apr 16, 2020 at 12:02 PM Bob <bweed at prodigy.net> wrote:

> Thanks for the education, Dave, W7KFO! I too have noise that wipes out 20
> meters when the furnace starts. Didn’t think about the washing machine but
> the dishwasher  gives me lots of electrical noise virtually all time it’s
> running.
>
>
>
> Bob, W7SCY
>
>
>
> *From:* HiDARG-Members [mailto:hidarg-members-bounces at hidarg.org] *On
> Behalf Of *Dave
> *Sent:* Thursday, April 16, 2020 11:48 AM
> *To:* hidarg-members at hidarg.org
> *Subject:* Re: [HiDARG-MEMBERS] Ferrite chokes
>
>
>
> One noise source in my home is a front load washing machine.  The motor
> control uses pulse width modulation to spin the drum at various speeds.
> Very distinctive noise signature as the drum speeds up in one direction,
> stops, then spins in the opposite direction.
>
> The furnace blower speed is also controlled by switching circuitry.  To
> make a long story short, use mix 31 ferrites on every offending appliance
> power cord.  Snap-ons do work, but much greater attenuation is available by
> using toroid rings and passing the cord (with plug still attached) thru the
> ring several times.  Attenuation (choking) increases as the square of the
> turns.  I buy my toroids by the ten pack, smaller ones for all the wall
> warts.  Palomar Engineers part #F240-31-10 work very well.  (Ten pack.)
> The 1.4 inch ID passes power plugs easily.
>
> 73, Dave
> W7KFO
>
> On 4/15/2020 9:31 PM, Mike Williams wrote:
>
> Sounds like a fox hunt 👍...
>
>
>
> On Wed, Apr 15, 2020, 8:57 PM Randy Tomer <w6ra.randy at gmail.com> wrote:
>
> Dave,
>
>
>
> If the noise is coming in through your  antenna you will need to find
> the noise source to fix the problem.  If it's coming in
>
> through your power cord and 12v supply then a toroid might help.  Toroids
> are also used to keep RF from your transmitter
>
> out of usb and audio cables, etc.
>
>
>
> Do you still have the noise if you unplug your antenna?  Likely it is
> being picked up by the antenna.  Local power poles are
>
> a common source, but so are plasma televisions and LED lights and many
> other things.  The location a noise source in your house can be
>
> found by turning off your circuit breakers one switch at a time and
> listening for a drop in your receive noise level.  Something like a
>
> modern refrigerator with a microprocessor in it could be a noise producer.
> In that case you can choke out the noise with snap on ferrites
>
> or by winding the power cord through a large toroid.
>
>
>
> You can find noisy power poles by walking around with a portable AM radio
> tuned to an empty frequency and listening for the static to
>
> get louder.  Also you can rotate the radio around to find a null in the
> noise; if the radio is a large portable the noise will be coming from
>
> a right angle from the radio.
>
>
>
> Hope this gives you a few ideas.
>
>
>
> Randy
>
>
>
>
>
> On Wed, Apr 15, 2020 at 8:03 PM Randy Tomer <w6ra.randy at gmail.com> wrote:
>
> I'm still looking, not found yet.  I need to order some myself.
>
>
>
> On Wed, Apr 15, 2020 at 10:32 AM Randy Tomer <w6ra.randy at gmail.com> wrote:
>
> Dave, I've got the specification and where to order some written down
> somewhere.
>
> I'll get the info to you later today.
>
>
>
> Randy
>
>
>
> On Wed, Apr 15, 2020 at 9:20 AM Dave Green <dgreen357 at gmail.com> wrote:
>
> Does anyone know if there's somewhere locally that I can pick up some
> ferrite chokes?  I have a constant  S7 noise floor across 40 & 80 that I
> need to try and lower or eliminate.
>
>
>
> 73
>
> Dave  "Doc" Green
>
> KT7DOC
>
> 541-771-1616
>
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> --
> Please *remove my email address* from messages you choose to forward.
> Thank you, Dave
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