Fortunately allocations at the top end of the MW band tend to
be "local" or regional ... typically 5 KW or so ... not the
50 KW monsters found lower in the band. Unless one lives
right next door to an extended band station, this filter is
going to do the job (it will effectively reduce a 5 KW station
100 W), particularly if the receiver also has a reasonable
front end filter and decent IMD specs.
73,
... Joe, W4TV
On 11/25/2010 7:53 PM, Richard (Rick) Karlquist wrote:
> Sorry to be a wet blanket, but now that the AM broadcast
> band extends to 1.7 MHz, you really have to use an
> elliptic function (AKA Cauer) filter, not a Chebyshev.
> There are several of those on the market (don't have
> the info handy).
>
> Rick N6RK
>
> On 11/25/2010 8:10 AM, Joe Subich, W4TV wrote:
>>
>> Hijacking an old e-mail for new information ...
>>
>> For those looking for solutions to eliminate/reduce overload from
>> nearby AM broadcast transmitters, Jack Smith, W8OZA at Clifton
>> Laboratories now has two interesting products.
>>
>> Model Z10022A is 9th order 1 dB Chebyshev highpass filter that
>> claims 1.6 dB insertion loss at 1.8 MHz, ~ 30 dB at 1.6 MHz,> 40
>> dB at 1.5 MHz and ultimate rejection around 100 dB below 1 MHz.
>> See:<http://cliftonlaboratories.com/z10022a_high_pass_filter.htm>
>>
>> The other filter is a band stop (band rejection) filter for the
>> AM band. The Z10020 allows reception below 540 MHz for those who
>> are also experimenting at VLF or DX the NDB band. See:
>> <http://cliftonlaboratories.com/z10020_am_medium_wave_band_reject_filter.htm>
>>
>>
>>
>> I have no connection to Clifton Laboratories but since the "how
>> to deal with AM interference/overload" issue pops up periodically,
>> I wanted to get this information into the archives in case anyone
>> else needs it.
>>
>> 73,
>>
>> ... Joe, W4TV
>>
>>
>> On 1/22/2007 6:27 PM, Tod-MN wrote:
>>> Has anyone more information regarding the schematic and values for this
>>> filter? Is it commercially available or is it 'one of a kind' and
>>> made of
>>> unobtanium?
>>>
>>> Tod, K0TO
>>>
>>>>
>>>> http://www.dallas.net/~jvpoll/Filter/TheAMBrickWall.html
>>>>
>>>
>>> _______________________________________________
>>> Topband mailing list
>>> Topband@contesting.com
>>> http://lists.contesting.com/mailman/listinfo/topband
>>>
>>>
>> _______________________________________________
>> UR RST IS ... ... ..9 QSB QSB - hw? BK
>>
>>
>
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