Topband: 1940 kHz intermod

Thu Apr 20 23:02:51 EDT 2023

   Let me know if this 1940 spur still exists. If yes, I’ll make some inquiries by other routes…

— Eric

> On Apr 20, 2023, at 14:57, A J <iamfromcanadaalso at gmail.com> wrote:
> 
> I contacted them last year, after all the help from people on here that confirmed where it was coming from.
> 
> Called a few times and tried to get to the station engineer; never happened.  I did explain to them what was happening etc. I do not recall who I had talked too.
> 
> Left it at that a period of time and it was gone, then it came back. I gave up.
> 
> Have not been on that frequency since it came back. Did not want to get the Government involved.
> 
> Hope you have better progress than I did.
> 
> Eric has some great info that I did not have.
> 
> 
> 
> Cheers AJ___ VE3HJ
> 
> 
> On 4/20/23 14:14, James V Redding PE via Topband wrote:
>> Call the owner/operator at
>> 
>> https://mrbi.net/
>> 
>> or more directly with a free cell phone call to:
>> 
>> *MRBI Headquarters*
>> 
>> 40 Exchange Place, Suite 1010
>> 
>> New York, NY 10005
>> Tel: 212-966-1059
>> Fax: 212-625-2894
>> and let them know of your concerns. It is not a small business. . . They
>> own 39 stations.
>> 
>> Curious! You did not mention that the program content was in Mandarin or
>> Spanish.
>> 
>> CUL,
>> 
>> Jim/VEZ
>> 
>> On Wed, Apr 19, 2023 at 10:35 PM Eric Scace K3NA <eric at k3na.org> <mailto:eric at k3na.org> wrote:
>> 
>>> Hi Frank, everyone —
>>> 
>>>    One does not need another person to be harmed by the intermod on 1940
>>> kHz
>>> 
>>>    AM broadcast regulations include a very strict bandwidth mask for any
>>> form of radiated spurious signal more than ±75 kHz from the carrier
>>> frequency. At these power levels, such spurs must be less than -80 dB below
>>> the carrier (measured at a point about 10 wavelengths from the center of a
>>> directional array, usually in the main beam).
>>> 
>>>    There are very specific measurement procedures to be followed for
>>> compliance. Every AM station is required to measure — and retain a report
>>> of compliance in their station transmitter logs — annually (no more than 14
>>> months between measurements). The measurement procedures require some care,
>>> a very good spectrum analyzer, and a calibrated antenna.
>>> 
>>>    If the station is out of compliance, it has 10 days to return to
>>> compliance before notifying the FCC. If the problem cannot be repaired
>>> within 28 days, the station must obtain an STA to continue operations.
>>> 
>>>    ===
>>> 
>>>    Now, as to the identity of the stations. The FCC’s AM Query <
>>> https://www.fcc.gov/media/radio/am-query> <https://www.fcc.gov/media/radio/am-query> webpage is invaluable for
>>> researching issues like this.
>>> 
>>>    Rick identified one audible program as from WWRU. WWRU operates 10 kW
>>> daytime with a 2-tower directional array at 40° 49' 13.36" N  74° 04'
>>> 02.51” W. The tower registration numbers are 1040103 and 1242403. At night
>>> it runs 10 kW into a 4-tower array
>>> 
>>>    A search of AM stations within 3 km reveals, as reported by others,
>>> WKDM on 1380 kHz. [Note: Be careful using AM Query’s “radius around a
>>> lat-long” search tool, as the input must be in NAD-27, not NAD-83
>>> coördinates.]
>>> 
>>>    WKDM uses a 3-tower directional array (daytime) at the same
>>> coördinates, and a 4-tower directional pattern at night. Tower #1040103 is
>>> shared by both stations. That means a diplexer is employed to combine the
>>> signals into this tower — and would be the first place to look for
>>> generation of a mixing product.
>>> 
>>>    ===
>>> 
>>>    What to do?
>>> 
>>>    Both stations run 10 kW or more. On that basis alone, the chief
>>> engineer of each station is required to be an employee of the station — not
>>> a contract engineer. (The same requirement applies to any AM station
>>> running a directional pattern.) That means the chief engineers will be easy
>>> to contact — just call the station’s main phone number. WKDM’s website is
>>> here <https://www.am1660.com/> <https://www.am1660.com/>, and info at am1680.com <mailto:info at am1680.com> <mailto:
>>> info at am1680.com> <mailto:info at am1680.com> is the general email address. +1-718-352-1660 is the
>>> phone number at their headquarters location.
>>> 
>>>    If this is unsuccessful, one can escalate to the points of contact
>>> registered with the station license. In this case, a search of the FCC LMS
>>> database reveals both stations are owned by the same company and have the
>>> same points of contact:
>>> seank at mrbi.net <mailto:seank at mrbi.net> <mailto:seank at mrbi.net> <mailto:seank at mrbi.net> … and the legal representative is
>>> Mark Lipp at lipp at fhhlaw.com <mailto:lipp at fhhlaw.com> <mailto:lipp at fhhlaw.com> <mailto:lipp at fhhlaw.com>
>>> 
>>>    If no satisfaction has been obtained, anyone can file a complaint with
>>> the FCC Enforcement Bureau explaining that these two stations are operating
>>> out of apparent compliance, with the support data and information about how
>>> the station management has been unresponsive. The Enforcement staff
>>> maintain contact numbers for each station to use in cases of emergency, and
>>> will follow up (as I have personally witnessed).
>>> 
>>>    I hope this helps.
>>> 
>>> — Eric K3NA
>>> 
>>> 
>>> 
>>> 
>>>> On Jan 6, 2023, at 18:03, Frank W3LPL <donovanf at starpower.net> <mailto:donovanf at starpower.net> wrote:
>>>> 
>>>> Hi Fred,
>>>> 
>>>> We've figured out the mystery, now we need to determine if anyone is
>>>> being harmed by the weak, intermittent intermod on 1940 kHz
>>>> 
>>>> 73
>>>> Frank
>>>> W3LPL
>>> _________________
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>>> Reflector
>>> 
>> _________________
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> -- 
> Knowledge is Power and Power is Knowledge.___AJ___1967  Tell me and I will forget. Teach me and I may learn. Involve me and I shall understand. ___AJ___