Hi Not to mention latest rise of solar arrays and MPPTs, chargers, inverters.
My neighbor installed one such an array and doesnt care so I had to resort to informing local authorities whi will be performing measurements (I measured 62dBuV at 10m distance, while limit is 50dBuV on the output of the inverter!! And since 110kHz is main frequency, I also often see birdies on harmonics, which are exactly the whole numbers... I moved all my beverages to nearby forest, 300m away, but still the QRM is few dB above noise when listening to NW. If this will go as it is we might lose the low bands from sub urban areas totally. Jiri OK2IT ________________________________ Od: Topband <[email protected]> za uživatele [email protected] <[email protected]> Odesláno: středa 27. května 2026 18:00 Komu: [email protected] <[email protected]> Předmět: Topband Digest, Vol 281, Issue 6 Send Topband mailing list submissions to [email protected] To subscribe or unsubscribe via the World Wide Web, visit http://lists.contesting.com/mailman/listinfo/topband or, via email, send a message with subject or body 'help' to [email protected] You can reach the person managing the list at [email protected] When replying, please edit your Subject line so it is more specific than "Re: Contents of Topband digest..." Today's Topics: 1. Industrial Birdies on Round Frequencies ([email protected]) 2. Re: Industrial Birdies on Round Frequencies (Robert Urban) ---------------------------------------------------------------------- Message: 1 Date: Wed, 27 May 2026 04:01:16 +0200 From: <[email protected]> To: <[email protected]> Subject: Topband: Industrial Birdies on Round Frequencies Message-ID: <[email protected]> Content-Type: text/plain; charset=UTF-8; format=flowed ?For many years on Top Band I have noticed one recurring problem which is becoming more and more significant, especially for stations using traditional receiving systems. A large amount of industrial QRN, heterodynes, birdies and various spurious carriers appear exactly on round kHz frequencies such as 1825.0, 1826.0, 1827.0 etc. Unfortunately, many DX stations also choose these exact frequencies when calling CQ. During my years on 160m I have lost several rare and potentially new DX QSOs only because the DX station happened to operate exactly on one of these whole-kHz frequencies where local industrial heterodynes made reception extremely difficult or even impossible. I would therefore like to kindly ask DX stations to consider using slightly offset frequencies when calling CQ on Top Band, for example 1825.3, 1826.7, 1829.4 etc., instead of exact integer frequencies. This is especially important for those of us who still use the traditional way of receiving ? our own antennas, local receiving arrays and real on-site receivers ? rather than remote SDR receivers located hundreds or thousands of kilometers away in electrically quiet locations. Today, a large number of DXers use remote SDR systems for reception, and naturally they often do not hear the same local industrial noise and heterodynes that many traditional stations still have to fight every night on 160m. A small frequency offset may seem insignificant, but in practice it can make the difference between a readable signal and a completely lost QSO. Thank you very much to everyone who takes this into consideration and helps keep Top Band enjoyable and accessible also for stations using classic receiving methods and local antennas. 73 Karel? OK1CF ------------------------------ Message: 2 Date: Tue, 26 May 2026 21:51:03 -0500 From: Robert Urban <[email protected]> To: [email protected] Cc: [email protected] Subject: Re: Topband: Industrial Birdies on Round Frequencies Message-ID: <ca+tmvk3ka9d6ujhzpik69l3uadkudjfytodlh29msr_ngnu...@mail.gmail.com> Content-Type: text/plain; charset="UTF-8" Thank you Karel. Similar problem here in NA involving Broadcast station harmonics. *Bob W9EWZ* On Tue, May 26, 2026 at 9:15?PM Karel via Topband <[email protected]> wrote: > For many years on Top Band I have noticed one recurring problem which is > becoming more and more significant, especially for stations using > traditional receiving systems. > A large amount of industrial QRN, heterodynes, birdies and various > spurious carriers appear exactly on round kHz frequencies such as 1825.0, > 1826.0, 1827.0 etc. Unfortunately, many DX stations also choose these exact > frequencies when calling CQ. > During my years on 160m I have lost several rare and potentially new DX > QSOs only because the DX station happened to operate exactly on one of > these whole-kHz frequencies where local industrial heterodynes made > reception extremely difficult or even impossible. > I would therefore like to kindly ask DX stations to consider using > slightly offset frequencies when calling CQ on Top Band, for example > 1825.3, 1826.7, 1829.4 etc., instead of exact integer frequencies. > This is especially important for those of us who still use the traditional > way of receiving ? our own antennas, local receiving arrays and real > on-site receivers ? rather than remote SDR receivers located hundreds or > thousands of kilometers away in electrically quiet locations. > Today, a large number of DXers use remote SDR systems for reception, and > naturally they often do not hear the same local industrial noise and > heterodynes that many traditional stations still have to fight every night > on 160m. > A small frequency offset may seem insignificant, but in practice it can > make the difference between a readable signal and a completely lost QSO. > Thank you very much to everyone who takes this into consideration and > helps keep Top Band enjoyable and accessible also for stations using > classic receiving methods and local antennas. > 73 > Karel OK1CF > > _________________ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > ------------------------------ Subject: Digest Footer _______________________________________________ Topband mailing list [email protected] http://lists.contesting.com/mailman/listinfo/topband ------------------------------ End of Topband Digest, Vol 281, Issue 6 *************************************** _________________ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
