John, you're lucky indeed! I'm right in town here and, although the higher
bands aren't bad with a resting noise level of s5 or so, I consistantly get
s7 to s8 on 80. I imagine its at least that high on 160, although I don't
have an antenna on that band. And that's another reason to operate CW, you
can null most of that noise out, especially with today's receivers. Lou
WA3MIX
Lou Kolb
Voice-over Artist:
Radio/TV Ads, Video narrations
Messages On-hold:
www.loukolb.com
----- Original Message -----
From: "John Miller" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Saturday, February 01, 2014 8:51 PM
Subject: Re: Low Pass Filter
> We have everything but the bug zappers here if not more so around me with
> no
> problem. I must just be lucky. The one time I did have noise the power
> company came out and fixed it, I told them what it was. They didn't
> believe
> me and fixed a lot of other potential and unknown problems in the area as
> well, then finally found the problem right where I told them it was and
> fixed that but that's the only problem I ever had here. I don't have much
> height for my antennas either though, you'd think I'd be unable to hear
> anything, I'm surprised daily and just waiting for that one electronic
> device to come in the area that takes me off the air.
> ----- Original Message -----
> From: "eric oyen" <[log in to unmask]>
> To: <[log in to unmask]>
> Sent: Saturday, February 01, 2014 8:05 PM
> Subject: Re: Low Pass Filter
>
>
>> well,
>> the situation here is a bit close. I have 12.6 Kv lines directly behind =
>> the hose. THe neighbors have outdoor florescent lights (and there are =
>> even 2 bug zappers). I have checked and there are at least 14 wi-Fi =
>> access points within 400 feet of me. THe house itself has 2 AP devices, =
>> about 300 feet of LAN cable, 2 switches and 6 computer systems (the room
>> =
>> mates have 3 desktop systems). I have 3 laptop machines, 2 of which are =
>> turned off. Half the lights in here are of the tube variety (those =
>> stupid cheap made "green lamps"). all of these make some noise. As a =
>> result, I also have to have an MFJ 2500 series antenna noise =
>> cancellation unit in operation here just to remove all the electrical =
>> noise. THe power lines are the worst of it.
>>
>> Basically, I am using every trick I can find to reduce or eliminate =
>> noise before it hits my radio.
>>
>> -eric
>>
>> On Feb 1, 2014, at 5:49 PM, John Miller wrote:
>>
>>> I actually never have lived in a place with a lot of noise. It's =
>> funny,=20
>>> when I first was a ham, I was living with my parents, in the woods =
>> pretty=20
>>> much with over a hundred feet between houses, well over 100 feet and =
>> all=20
>>> woods behind me. Next place, in a neighboring town I was in an =
>> apartment in=20
>>> the center of town, surrounded in a factory, houses, other businesses, =
>> a=20
>>> place that converts vans to wheel chair vans and works on them, still =
>> never=20
>>> had any noise for what ever reason and there you could about reach out =
>> and=20
>>> touch the neighbors. Now I'm in a trailer park and we're not much =
>> further=20
>>> away form each other I have a light off and on buzz here that my
>>> noise=20=
>>
>>> blanker takes out and other than that, again very quiet. 2 meters I =
>> have=20
>>> noise but I couldn't care less about that and even that is rare. I =
>> don't=20
>>> know why I'm that lucky. I spent 2 months with my in-laws at one =
>> point,=20
>>> there, I had a +40 noise level from 160 through 70 CM, I could get on =
>> GMRS,=20
>>> and 900 MHz from there, that was about it and no filtering remotely =
>> helped=20
>>> that but that was an area with all businesses and apartments above =
>> them once=20
>>> in a while.
>>> ----- Original Message -----=20
>>> From: "eric oyen" <[log in to unmask]>
>>> To: <[log in to unmask]>
>>> Sent: Saturday, February 01, 2014 7:00 PM
>>> Subject: Re: Low Pass Filter
>>>=20
>>>=20
>>>> the funny thing is that low pass filters operate bi-directionally. If =
>> =3D
>>>> your radio produces harmonics that interfere above its normal =
>> operating =3D
>>>> range, then mix down products from sources above HF would also cause =
>> =3D
>>>> interference on HF. THese mix down products are often caused by =3D
>>>> interactions within the first stage of the IF in your radio. SO, =
>> using a =3D
>>>> filter eliminates a lot of that from getting to your radio (thus =3D
>>>> reducing or eliminating the problem).
>>>>=20
>>>> I have an FM radio station transmitter site less than 3 miles from me =
>> =3D
>>>> producing several thousand watts. without the filter, I hear what =
>> sounds =3D
>>>> like FM modulated signals in a couple of bands. I put the filter in
>>>> =3D=
>>
>>>> place, and those signals disappeared. THere are other sources (such =
>> as a =3D
>>>> wireless Access point, LAN switches and cable modems'DSL modems that =
>> =3D
>>>> produce signals that can show up in HF directly. Filtering these is a =
>> =3D
>>>> bit harder. I am having to use ferrite beads on the power leads and =
>> also =3D
>>>> on the LAN cables to try and minimize some of these issues. I have =
>> only =3D
>>>> been partially successful. I still get a lot of birdies in the 10 =
>> meter =3D
>>>> band (around 28.5). I am going to acquire a portable shortwave =
>> receiver =3D
>>>> and try to track these signals to their source and see what I can do =
>> to =3D
>>>> remove them.
>>>>=20
>>>> -eric
>>>>=20
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