I've been reading the mail on this. Some time ago at Home Depot, I purchased a
little device that tests electrical outlets for proper connections and the
safety ground. Very inexpensive and easy to use. Sometimes checking house
wiring for proper connections can reveal some interesting results. I found two
outlets that I thought had proper safety grounds when they really didn't. It
also checks the proper neutral and hot wiring to the outlets.
I have two Astron 35 M supplies, one is at least 20 years old and the other
about a year old. Have not experienced the hum trouble here, but the old
Astron has failed a couple times.
Just my .02
GL & 73
Dale, K9VUJ
On 11, Apr 2014, at 0:49, Gary Smith <Gary@ka1j.com> wrote:
> A couple of things...
>
> I took Jim's advice and stocked up on #31 ferrites, bought a bunch of
> them, more than I'll probably ever use but I'm going to put them on
> every power outlet possible, I've already started making up extension
> cords to be clamped with the ferrites and from that, to a power
> strip. Where that's not practical, every wall wart will have turns of
> the wire ferrited. You get the idea. The noise I hear and see on the
> P3 is now remarkably reduced.
>
> I've had more noise in my HI-Z Rx antenna than I think I should have
> so I put these ferrite clamp-ons at each end of the coax (in loops)
> to each antenna and at the end at the control box. Same for all the
> other coax involved in the HI-Z and it has made a difference but I'm
> really not sure why.
>
> As to the Keurig & the Astron... I do love the Keurig, I use the
> refillable coffee holders and it does make a fine cup but I digress.
> As was mentioned earlier, the Astron was terribly made as regards
> grounding. The wire grounding from the negative DC out was bolted to
> the chassis but it was on paint on both sides and the round plug was
> attached to the chassis exactly the same way. I connected both of
> these ring terminals to one bolt and removed the paint on both sides
> to make a true ground.
>
> I tried figuring out what was making the hum in the Astron when the
> Keurig was on and it seems to be coming from the transformer (which
> is really warmer than I expected). I removed the DC connection and
> just had the Astron plugged into the AC and I still was hearing that
> intermittent humming when the Keurig was on. Nothing I could press on
> in the PS made the noise stop. I finally put three large ferrite
> clamp-ons with three loops each on the power cord to the Astron and
> now I can still hear the hum but now it's greatly reduced and hard to
> hear over the fan in the amp, so that is a real bit of progress.
>
> 73,
>
> Gary
> KA1J
>
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