Re: Topband: BCB Filter Recommendation?
I built the AM BC filter that W1VLF made for one of my SDR servers as a test. Works well, but users now can only hear/see the strongest of AM BC stations. This is a RX only filter, not able to TX through it! I used axial-lead inductors in mine and mounted it in a home-made box made from Copper flashing material. There is some slight loss in the 160M CW portion due to not a steep skirt on the filter, but it reduced the QRM on higher frequencies on the SDRPlay that’s connected to that server. Schematic is in the video: https://www.youtube.com/watch?v=vI6N_uVErKA 73 Kriss KA1GJU Sent from Mail for Windows 10 _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: BCB Filter Recommendation?
On 4/17/2020 6:22 AM, Joe wrote: Is radio manufacturers that include steep filters and even attenuators in their radios to block AM Broadcast band signals. Then advertise that their radio covers from 50 KC to 60 Mhz! Sorry NO IT DOES NOT!!! It is extremely sad when a ten buck radio with it's internal ferrite bar antenna performs better than my $4000.00 dollar radio using a 600 foot loop up 60 feet antenna! Joe WB9SBD Sig The AM BCB is unique, compared to 160/630/2200 meters, in that every channel is occupied by multiple strong signals 24/7 that are strong enough to overcome receiver noise with a tuned ferrite bar antenna. A 600 foot loop is omni directional and horizontally polarized and thus IMHO is a non-starter for BCB DX. If you want to go beyond the ferrite bar antenna, you could put up short beverages. I used to have six beverages spaced at 60 degrees azimuth that were only 400 feet long. Although "too short" for BCB, in fact they were VERY directional. On a typical channel, at least 3 different stations could be received, each on its own beverage. In some cases 4 or 5 different stations could be heard. My pocket size Sangean radio ($60 not $10) has amazing nulling capability for power line noise due to its small antenna (better nulling than a big loop). I remember an amazing incident with this radio when I was listening to a station in San Diego on 770 kHz IIRC and I accidentally turned the radio so as to null out this station. Up popped WJR in Detroit. Not bad AM DX for a pocket radio on the left coast. And now back to HAM radio. 73 Rick N6RK _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: BCB Filter Recommendation?
What makes me most angry? Is radio manufacturers that include steep filters and even attenuators in their radios to block AM Broadcast band signals. Then advertise that their radio covers from 50 KC to 60 Mhz! Sorry NO IT DOES NOT!!! Yes make the filters and or attenuators but make them so WE can choose when to have them on or not! Make them switchable! There is no reason why this can not be done! Some people do not live near a station they have to worry about. And like to do AM Band DXing! It is extremely sad when a ten buck radio with it's internal ferrite bar antenna performs better than my $4000.00 dollar radio using a 600 foot loop up 60 feet antenna! LET US decide if we need the filtering or not! Joe WB9SBD Sig The Original Rolling Ball Clock Idle Tyme Idle-Tyme.com http://www.idle-tyme.com On 4/17/2020 6:16 AM, Rob Atkinson wrote: Most AM plants have been where they are for decades. I remember being at the local 670 site several years ago. That tx site has been there since the 1930s. This is a ~800 foot tower, now with two signals on it, 670 and 780, each 50 KW which means the total peak power on positive modulation is roughly 400 KW. I recall seeing a little 60 foot ham tower about a block away with a 3 el. beam on it, and wondering how any ham could be dumb enough to buy a house in the shadow of a major market ND class A-1 station.I would not even consider buying a house near a 1 KW daytimer. I'm about 10 miles from the 670 site and that's bad enough. Being a quarter mile from it would be a nightmare. 73 Rob K5UJ _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: BCB Filter Recommendation?
Most AM plants have been where they are for decades. I remember being at the local 670 site several years ago. That tx site has been there since the 1930s. This is a ~800 foot tower, now with two signals on it, 670 and 780, each 50 KW which means the total peak power on positive modulation is roughly 400 KW. I recall seeing a little 60 foot ham tower about a block away with a 3 el. beam on it, and wondering how any ham could be dumb enough to buy a house in the shadow of a major market ND class A-1 station.I would not even consider buying a house near a 1 KW daytimer. I'm about 10 miles from the 670 site and that's bad enough. Being a quarter mile from it would be a nightmare. 73 Rob K5UJ _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: BCB Filter Recommendation?
Hi Rick, Thanks for that - good point about Inverse chebyshev. and the toroids were dust iron… We’re fortunate in not having mega strong signals near the top of the MW band here. Jeremy > On 17 Apr 2020, at 05:24, Richard (Rick) Karlquist > wrote: > > > > On 4/16/2020 2:45 PM, Jeremy Maris wrote: >> Make your own! >> Use this site to design your filter. >> http://www.iowahills.com/9RFFiltersPage.html >> Attached are the values I used back in 2016 when the G4AQG FT-1000MP had >> intermod problems with a new Beverage. >> I built a 9 pole Chebyshev high pass filter, designed with the excellent RF >> filter design package from Iowa Software, and used an LC meter to get the >> capacitor and inductor values correct. Caps were made from polystyrene and >> inductors wound on small ferrite torroids.. >> Difficult to see from the (ancient!) spectrum analyzer picture but the >> filter response was almost exactly as the design showed. >> No labels for stop-band but it was 10dB down at 1579kHz, 50dB down at >> 1000kHz and at 693kHz was in the noise, at least 70dB down, almost >> undetectable compared to 60dB over S9 or more without the filter, and the >> intermod was gone. > > The good filters use INVERSE Chebyshev designs, > made with mica or C0G capacitors, and powdered iron cores. > 10 dB down at 1579 kHz is not good enough for many QTH's. > I have a very strong local station at 1700 kHz, > for example, and another at 1530 kHz. > > Rick N6RK Jeremy Maris 140 Edward Street, Brighton BN2 0JL jer...@maris.plus.com _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: BCB Filter Recommendation?
On 4/16/2020 9:24 PM, Richard (Rick) Karlquist wrote: 10 dB down at 1579 kHz is not good enough for many QTH's. I have a very strong local station at 1700 kHz, for example, and another at 1530 kHz. As Rick and Frank have observed, the operating frequency(ies) of the BC stations you need to suppress matters a lot. The better 160M bandpass filters are probably all you need for a BC station low in the band, but you'll need to go in loaded for bear to kill a strong station high in the band. 73, Jim K9YC _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: BCB Filter Recommendation?
On 4/16/2020 2:45 PM, Jeremy Maris wrote: Make your own! Use this site to design your filter. http://www.iowahills.com/9RFFiltersPage.html Attached are the values I used back in 2016 when the G4AQG FT-1000MP had intermod problems with a new Beverage. I built a 9 pole Chebyshev high pass filter, designed with the excellent RF filter design package from Iowa Software, and used an LC meter to get the capacitor and inductor values correct. Caps were made from polystyrene and inductors wound on small ferrite torroids.. Difficult to see from the (ancient!) spectrum analyzer picture but the filter response was almost exactly as the design showed. No labels for stop-band but it was 10dB down at 1579kHz, 50dB down at 1000kHz and at 693kHz was in the noise, at least 70dB down, almost undetectable compared to 60dB over S9 or more without the filter, and the intermod was gone. The good filters use INVERSE Chebyshev designs, made with mica or C0G capacitors, and powdered iron cores. 10 dB down at 1579 kHz is not good enough for many QTH's. I have a very strong local station at 1700 kHz, for example, and another at 1530 kHz. Rick N6RK _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: BCB Filter Recommendation?
What RX loop to do have? 73! Mark KA6WKE Website: https://www.ka6wke.net On Thu, Apr 16, 2020, 11:34 Edward via Topband wrote: > Greetings, > > I am getting clobbered by a local BCB transmitter, making 160M unusable, > even with a dedicated RX antenna. > > As for filters, I have narrowed it down to the ICE and the Kiwa. Kiwa > seems to be the more serious filter, as they publish their specs in great > detail. ICE does not. > > Any other filter I should consider besides these two? > > > Thanks, > Ed 7Z1ES > _ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: BCB Filter Recommendation?
Yeah a few of my earlier videos are used to cure insomnia. I'm still trying to figure out my niche. 73! Mark KA6WKE Website: https://www.ka6wke.net On Thu, Apr 16, 2020, 14:49 Mike Waters wrote: > Oh sure! I was just trying to say that some of your videos appear to be > worth my time to watch. :-) > > 73 Mike > W0BTU > > On Thu, Apr 16, 2020, 4:46 PM Mark Schoonover wrote: > >> I understand but text only would make it impossible to view the >> improvements. >> >> 73! Mark KA6WKE >> >> Latest Video: https://ka6wke.net/gmail >> Website: https://www.ka6wke.net >> >> >> >> On Thu, Apr 16, 2020 at 12:26 PM Mike Waters wrote: >> >>> This looks interesting, even though I would rather read text than watch >>> a video. I just bookmarked it, and will watch some later. Thanks! >>> >>> 73, Mike >>> W0BTU >>> >>> On Thu, Apr 16, 2020, 2:08 PM Mark Schoonover wrote: >>> Website: https://www.ka6wke.net >>> _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: BCB Filter Recommendation?
Here’s a link to the values I used, seeing as it doesn’t get through the reflector. http://www.g4aqg.sussex.ac.uk/9-pole-chebyshev-1500-exactvalues.tiff Built in an evening in a diecast box with BNC sockets, dead bug construction on single sided PCB and copper foil screening between sections. Jeremy > On 16 Apr 2020, at 22:45, Jeremy Maris wrote: > > Make your own! Jeremy Maris G3XDK / G4AQG _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: BCB Filter Recommendation?
Ed, If your receive loop has a preamp at its feed point, its very likely that the preamp is being overloaded by the nearby BCB station. If that's the case, a filter after the preamp will not help. 73 Frank W3LPL - Original Message - From: "Edward" To: donov...@starpower.net Sent: Thursday, April 16, 2020 9:51:51 PM Subject: Re: Topband: BCB Filter Recommendation? Yes. I have a receive only loop. Thanks for the link. Will check it out. > On 17 Apr 2020, at 00:49, donov...@starpower.net wrote: > > Hi Ed, > > Do you currently route your 160 meter antenna through the receive only input? > If not, you must have the capability to do so to use this filter. > > This is by far the least expensive 160 meter receive filter and its rejection > at 1400 kHz is approximately 60 dB. But you have to build it yourself > from inexpensive components. Its a band pass filter so you'll need to > bypass it to operate on other bands. Countless hundreds of these > 160 meter filters have have been built. > > www.k1ttt.net/technote/w3lplfil.html > > 73 > Frank > W3LPL > > - Original Message - > > From: "Edward" > To: donov...@starpower.net > Sent: Thursday, April 16, 2020 9:35:34 PM > Subject: Re: Topband: BCB Filter Recommendation? > > I have receive-only inputs on my rigs. > > On 17 Apr 2020, at 00:07, donov...@starpower.net wrote: > > Hi Ed, > > Does your station layout allow you to use a receive only filter? > > 73 > Frank > W3LPL > > ----- Original Message ----- > > From: "Edward" > To: donov...@starpower.net > Sent: Thursday, April 16, 2020 8:36:59 PM > Subject: Re: Topband: BCB Filter Recommendation? > > > Thank you, Frank! > > > On 16 Apr 2020, at 22:06, donov...@starpower.net wrote: > > Hi Ed, > > What is the frequency of your local BCB transmitter? > > This is the best brickwall filter -- capable of handling 200 watts -- > that money can buy. Its provides at least 40 dB of attenuation below > 1700 kHz. Several PVRC members located within a few thousand > feet of a 50 KW 1500 kHz BCB transmitter use them with excellent > success. > > www.dxengineering.com/parts/dlw-fl1718 > > Less expensive filters work fine if your local BCB transmitter is below > 1500 kHz. You can save even more money if you can place the filter > before the receiver input to your radio, so the components don't have > to be rated for 200 watts. > > > 73 > Frank > W3LPL > > - Original Message - > > From: "Edward via Topband" > To: topband@contesting.com > Sent: Thursday, April 16, 2020 6:34:21 PM > Subject: Topband: BCB Filter Recommendation? > > Greetings, > > I am getting clobbered by a local BCB transmitter, making 160M unusable, even > with a dedicated RX antenna. > > As for filters, I have narrowed it down to the ICE and the Kiwa. Kiwa seems > to be the more serious filter, as they publish their specs in great detail. > ICE does not. > > Any other filter I should consider besides these two? > > Thanks, > Ed > 7Z1ES _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: BCB Filter Recommendation?
Make your own! Use this site to design your filter. http://www.iowahills.com/9RFFiltersPage.html Attached are the values I used back in 2016 when the G4AQG FT-1000MP had intermod problems with a new Beverage. I built a 9 pole Chebyshev high pass filter, designed with the excellent RF filter design package from Iowa Software, and used an LC meter to get the capacitor and inductor values correct. Caps were made from polystyrene and inductors wound on small ferrite torroids.. Difficult to see from the (ancient!) spectrum analyzer picture but the filter response was almost exactly as the design showed. No labels for stop-band but it was 10dB down at 1579kHz, 50dB down at 1000kHz and at 693kHz was in the noise, at least 70dB down, almost undetectable compared to 60dB over S9 or more without the filter, and the intermod was gone. > On 16 Apr 2020, at 19:34, Edward via Topband wrote: > > Greetings, > > I am getting clobbered by a local BCB transmitter, making 160M unusable, even > with a dedicated RX antenna. > > As for filters, I have narrowed it down to the ICE and the Kiwa. Kiwa seems > to be the more serious filter, as they publish their specs in great detail. > ICE does not. > > Any other filter I should consider besides these two? > > > Thanks, > Ed 7Z1ES > _ > Searchable Archives: http://www.contesting.com/_topband - Topband Reflector 73, Jeremy Maris G3XDK / G4AQG _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: BCB Filter Recommendation?
Nicely done, Mark. Plan to get ferrites. > On 17 Apr 2020, at 00:46, Mark Schoonover wrote: > > I understand but text only would make it impossible to view the > improvements. > > 73! Mark KA6WKE > > Latest Video: https://ka6wke.net/gmail > Website: https://www.ka6wke.net > > > >> On Thu, Apr 16, 2020 at 12:26 PM Mike Waters wrote: >> >> This looks interesting, even though I would rather read text than watch a >> video. I just bookmarked it, and will watch some later. Thanks! >> >> 73, Mike >> W0BTU >> >>> On Thu, Apr 16, 2020, 2:08 PM Mark Schoonover wrote: >>> >>> >>> Website: https://www.ka6wke.net >>> >> > _ > Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: BCB Filter Recommendation?
Oh sure! I was just trying to say that some of your videos appear to be worth my time to watch. :-) 73 Mike W0BTU On Thu, Apr 16, 2020, 4:46 PM Mark Schoonover wrote: > I understand but text only would make it impossible to view the > improvements. > > 73! Mark KA6WKE > > Latest Video: https://ka6wke.net/gmail > Website: https://www.ka6wke.net > > > > On Thu, Apr 16, 2020 at 12:26 PM Mike Waters wrote: > >> This looks interesting, even though I would rather read text than watch a >> video. I just bookmarked it, and will watch some later. Thanks! >> >> 73, Mike >> W0BTU >> >> On Thu, Apr 16, 2020, 2:08 PM Mark Schoonover wrote: >> >>> >>> Website: https://www.ka6wke.net >>> >> _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: BCB Filter Recommendation?
I understand but text only would make it impossible to view the improvements. 73! Mark KA6WKE Latest Video: https://ka6wke.net/gmail Website: https://www.ka6wke.net On Thu, Apr 16, 2020 at 12:26 PM Mike Waters wrote: > This looks interesting, even though I would rather read text than watch a > video. I just bookmarked it, and will watch some later. Thanks! > > 73, Mike > W0BTU > > On Thu, Apr 16, 2020, 2:08 PM Mark Schoonover wrote: > >> >> Website: https://www.ka6wke.net >> > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: BCB Filter Recommendation?
This looks interesting, even though I would rather read text than watch a video. I just bookmarked it, and will watch some later. Thanks! 73, Mike W0BTU On Thu, Apr 16, 2020, 2:08 PM Mark Schoonover wrote: > > Website: https://www.ka6wke.net > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: BCB Filter Recommendation?
I had the same problem - 0.8 miles away from 50KW station on 760KHz. I don't use a high pass filter on my main antenna but what I did do was wrap as many turns as possible through a mix 76 toroid and that really knocked down my problems. My problem was common mode on the outside of the coax. 73! Mark KA6WKE Latest Video: https://ka6wke.net/gmail Website: https://www.ka6wke.net On Thu, Apr 16, 2020 at 11:34 AM Edward via Topband wrote: > Greetings, > > I am getting clobbered by a local BCB transmitter, making 160M unusable, > even with a dedicated RX antenna. > > As for filters, I have narrowed it down to the ICE and the Kiwa. Kiwa > seems to be the more serious filter, as they publish their specs in great > detail. ICE does not. > > Any other filter I should consider besides these two? > > > Thanks, > Ed 7Z1ES > _ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
Re: Topband: BCB Filter Recommendation?
Hi Ed, What is the frequency of your local BCB transmitter? This is the best brickwall filter -- capable of handling 200 watts -- that money can buy. Its provides at least 40 dB of attenuation below 1700 kHz. Several PVRC members located within a few thousand feet of a 50 KW 1500 kHz BCB transmitter use them with excellent success. www.dxengineering.com/parts/dlw-fl1718 Less expensive filters work fine if your local BCB transmitter is below 1500 kHz. You can save even more money if you can place the filter before the receiver input to your radio, so the components don't have to be rated for 200 watts. 73 Frank W3LPL - Original Message - From: "Edward via Topband" To: topband@contesting.com Sent: Thursday, April 16, 2020 6:34:21 PM Subject: Topband: BCB Filter Recommendation? Greetings, I am getting clobbered by a local BCB transmitter, making 160M unusable, even with a dedicated RX antenna. As for filters, I have narrowed it down to the ICE and the Kiwa. Kiwa seems to be the more serious filter, as they publish their specs in great detail. ICE does not. Any other filter I should consider besides these two? Thanks, Ed 7Z1ES _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector _ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector
