Beat me to it. The three laws in order. 1. When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong. 2. The only way of discovering the limits of the possible is to venture a little way past them into the impossible. 3. Any sufficiently advanced technology is indistinguishable from magic.
@Alexej Svirid Modern study guides (anything written within the last eighteen centuries) were written, modified, and controlled by men. THey are inaccurate copies/interpretations. I will stick with the original texts. :) Like I stick with my 1930's antenna book.
As you say Dave, “ might learn something, or remember what you forgot. As an old Army Signal Corps RTTY guy, it’s mostly forgot. Your vids help to bring much of it back. VERY appreciated! Stay safe, 73
Great mini-series on noise... The best thing about FT8 & FT4, turn the speaker down to zero! What noise? Why none at all; well, to your ears! Thanks Dave! 73
a great deal of information however an audio demonstration of different noises and how to eliminate them would be a great help for the beginner hf operators
Thanks Dave for a (as always) good and interesting video! One noise source we've discussed here is roof solar panels! The panels generate DC current that has to be chopped up to your AC frequency (50 Hz here). The chopping electronics can be poorly constructed and dc lines from panels act as transmitting antennas.
Thought I knew most everything about noise - then I watched your video on noise reduction. Will be watching this again and again, taking notes. Thanks David, for the education.
I once had an intermittent blast of noise . Finally tracked it down using a portable AM radio and used it to triangulate on the noise. I quickly located it to a corner of our living room where the TV sits along with my aquarium. The problem was the aquarium heater and a simple filter took care of the problem.
The type of used antenna is of big influence on noise levels fed into a receiver. I (almost) never use transmit antennas when receiving. Most of my reception antennas are low noise models like a Beverage and most Loops. I let my tranceiver switch between them when transmitting and receiving. I also use a separate SDR when I release the PTT. The best thing that ever happened to me is using real diversity receiving with suited antennas. Mostly I turn a loop as you mentioned to receive the minimum level of qrm and steer the diversity, so the wanted signal has the best SNR. I do not care about signal level indications. There are decent SDR's that can manage real time coherent diversity, like an RSPduo or an Afedri AFE822x. There is still a problem when you have QRM that comes from different directions. Thanks for the detailed video's on the subject!
Dave, thank you for another very well presented subject. Noise may well be one of the most common and often misunderstood dynamics within the amateur radio hobby. Learning to understand it, reduce it and even eliminate it where possible can make the difference between a frustrating, seemingly unusable station condition and being able to copy even the weakest of signals resulting the great satisfaction of catching that elusive "rare" one! 73' de Chris W6NOB DM14ei Wrightwood, CA USA
Ok... I Guess I'll Use the ground lug on my boat anchor Receiver! DOh..... I just spent over a year overhauling! watched all the way to the End!LOL.73' jim KB1PFL
Thank you for an excellent video, went and looked at my grounding rod after watching this and found my rod in a very poor state, a tree had grown next to it and had broken my connection to it, I will now replace it and hope that is the answer to my S5/7 noise level on 40 Mtr,s VK3HJW
As always, good stuff. I was forced into an apartment. S9+ hash up to 22 MHz. I am missing my SWL. I know a bit about this. I found the local DSL utility is transmitting a frying signal all across HF. It's origin is a DSLAM box about 50 yards from my place. Of course, all those pairs (POTS) are radiating like antenna. It is likely a PSU in the box is causing this. I have attempted a few times to get their assist. They have no clue what I am talking about. They keep closing the tickets without action. Time to contact Laura.
Very good video. Only issue I have is that with a second floor shack the cable to ground is very long. In my case the shortest run to ground is 36 to 40 feet. I found at that length it caused more problems than it curers. I have reduced my noise floor from 59 to 59+20 to 54 with better coax and grounding at the feed point. Even with this improvement some days the bands are unworkable. Not a lot you can do ion a small plot and surrounded by other homes.
Art Bell knows about static electricity built up on your antenna as he had as much as 600 volts of static build on his antenna array that was coming into his shack . He spotted this by noticing arcing around the feed point coming through the wall .
The Lowfers have a bunch of modes designed to punch through noise. They have extreme restrictions technically that at first glance would make it seem impossible.Noise on that band (165 - 190Khz) is atrocious. Power is restricted to 1 watt and an antenna that is at most 0.008 wavelength. Imagine 10 meters using a 4 inch antenna! There have been several computer based modes designed to still punch through. There have been contacts of over 1000 miles.
I often turn off the AGC on the IC-7300 while working digital modes. If you do it it may be necessary to turn down the RF gain also. This is especially effective when there is a very strong signal near your working frequency. de Rich JS6TRQ / WC8J
yea but my problem the antennas are in fenced yard there is a half a lot to the back. an alley goes threw and some kid would come along and have fun so most of my antennas are closer to the house
What do I do if you can't ground the radio. I ask that because to get the grounding wire from my radio outside to the grounding rod would require about about 70ft of grounding wire. I was told a grounding wire should not be that long as it will then turn into an antenna. So how can I ground the radio with such a long grounding wire? Would it least help if I just grounded all the radio equipment to just a copper pipe inside the house without the copper pipe being grounded to the grounding rod outside?
At 9:00 is a good example of ground current causing problems do to Too Many Grounds Not Bonded To The Utility Ground! That is one of the reasons that the ground rod exists other than, as Judge Dred would say: "It's the Law." NEC 810: pslara.org/docs/2.D.pdf
Dave, on a typical mobile or magmount, the "wind" is high but there's never a ground from the whip element. Should there be one to reduce static and noise?
I've always wondered what the relative effectiveness of the clamp-on split ferrite beads is versus a solid bead, versus looping through a ferrite ring, e.g., how many split beads equal a one loop through a ring? I'm sure it's not a straight forward comparison, but I would still like to get a sense so that I could know if it's worth the extra effort to use rings or can I come close with the easy clamp=ons. 73, Bob, WK2Y
I have often had to give my callsign many times because the listener had their DNR turned up so high they couldn't tell Alpha from Oscar! I Do Not like DNR and will not use it except for the last resort. Distorts the intelligibility of the received signal too much.
Any sufficiently advanced technology is indistinguishable from magic. Arthur C. Clarke's third law.
Beat me to it. The three laws in order.
1. When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong.
2. The only way of discovering the limits of the possible is to venture a little way past them into the impossible.
3. Any sufficiently advanced technology is indistinguishable from magic.
@Alexej Svirid Modern study guides (anything written within the last eighteen centuries) were written, modified, and controlled by men. THey are inaccurate copies/interpretations. I will stick with the original texts. :) Like I stick with my 1930's antenna book.
Every video of yours is an exciting session and learning opportunity. Thank you Dave. At 80, so much to learn and so little time left.
As you say Dave, “ might learn something, or remember what you forgot. As an old Army Signal Corps RTTY guy, it’s mostly forgot. Your vids help to bring much of it back. VERY appreciated! Stay safe, 73
Great mini-series on noise...
The best thing about FT8 & FT4, turn the speaker down to zero! What noise? Why none at all; well, to your ears!
Thanks Dave! 73
Love your videos,… watching from Kentucky “The Bluegrass State “ !
a great deal of information however an audio demonstration of different noises and how to eliminate them would be a great help for the beginner hf operators
Thanks Dave for a (as always) good and interesting video!
One noise source we've discussed here is roof solar panels! The panels generate DC current that has to be chopped up to your AC frequency (50 Hz here). The chopping electronics can be poorly constructed and dc lines from panels act as transmitting antennas.
Thought I knew most everything about noise - then I watched your video on noise reduction. Will be watching this again and again, taking notes. Thanks David, for the education.
I once had an intermittent blast of noise . Finally tracked it down using a portable AM radio and used it to triangulate on the noise. I quickly located it to a corner of our living room where the TV sits along with my aquarium. The problem was the aquarium heater and a simple filter took care of the problem.
Wow Dave you out done yourself. These two videos were full of great tips. Thank you very much. 73's Clark KG7LOI.
The type of used antenna is of big influence on noise levels fed into a receiver. I (almost) never use transmit antennas when receiving. Most of my reception antennas are low noise models like a Beverage and most Loops. I let my tranceiver switch between them when transmitting and receiving. I also use a separate SDR when I release the PTT.
The best thing that ever happened to me is using real diversity receiving with suited antennas. Mostly I turn a loop as you mentioned to receive the minimum level of qrm and steer the diversity, so the wanted signal has the best SNR. I do not care about signal level indications. There are decent SDR's that can manage real time coherent diversity, like an RSPduo or an Afedri AFE822x. There is still a problem when you have QRM that comes from different directions. Thanks for the detailed video's on the subject!
Dave, thank you for another very well presented subject. Noise may well be one of the most common and often misunderstood dynamics within the amateur radio hobby. Learning to understand it, reduce it and even eliminate it where possible can make the difference between a frustrating, seemingly unusable station condition and being able to copy even the weakest of signals resulting the great satisfaction of catching that elusive "rare" one! 73' de Chris W6NOB DM14ei Wrightwood, CA USA
Very good pair of videos. I just watched them back to back. I think I need to study my FTDX-3000 manual. Thanks Dave!
Thank you Dave, that was an outstanding explanation and brings this very old HAM a little closer to being up to date.
Thumbing their noises--love it!
Great 2 videos. It helped me a lot with the noise thank you. I live in heavy commercial area.
Ok... I Guess I'll Use the ground lug on my boat anchor Receiver! DOh..... I just spent over a year overhauling! watched all the way to the End!LOL.73' jim KB1PFL
Thank you for an excellent video, went and looked at my grounding rod after watching this and found my rod in a very poor state, a tree had grown next to it and had broken my connection to it, I will now replace it and hope that is the answer to my S5/7 noise level on 40 Mtr,s VK3HJW
Dave, it is too theoretical. Plase provide 3rd part showing all this working on your radio. Thanks in advance. 73, Marcin SQ5SUM
As always, good stuff. I was forced into an apartment. S9+ hash up to 22 MHz. I am missing my SWL. I know a bit about this. I found the local DSL utility is transmitting a frying signal all across HF. It's origin is a DSLAM box about 50 yards from my place. Of course, all those pairs (POTS) are radiating like antenna. It is likely a PSU in the box is causing this. I have attempted a few times to get their assist. They have no clue what I am talking about. They keep closing the tickets without action. Time to contact Laura.
Thanks very much! Very informative and useful information clearly presented. I'm working on various noise problems in a new shack/radio environment.
Very good video. Only issue I have is that with a second floor shack the cable to ground is very long. In my case the shortest run to ground is 36 to 40 feet. I found at that length it caused more problems than it curers. I have reduced my noise floor from 59 to 59+20 to 54 with better coax and grounding at the feed point. Even with this improvement some days the bands are unworkable. Not a lot you can do ion a small plot and surrounded by other homes.
Art Bell knows about static electricity built up on your antenna as he had as much as 600 volts of static build on his antenna array that was coming into his shack . He spotted this by noticing arcing around the feed point coming through the wall .
Suppose the noise is from a close bye adjescent house? Case of densely populated areas.
The Lowfers have a bunch of modes designed to punch through noise. They have extreme restrictions technically that at first glance would make it seem impossible.Noise on that band (165 - 190Khz) is atrocious. Power is restricted to 1 watt and an antenna that is at most 0.008 wavelength. Imagine 10 meters using a 4 inch antenna! There have been several computer based modes designed to still punch through. There have been contacts of over 1000 miles.
I often turn off the AGC on the IC-7300 while working digital modes. If you do it it may be necessary to turn down the RF gain also. This is especially effective when there is a very strong signal near your working frequency. de Rich JS6TRQ / WC8J
High SNR on this video Dave, thank you and 73 from W0DJB
Super Dave! Thanks & 73, John/N6VTS
yea but my problem the antennas are in fenced yard there is a half a lot to the back. an alley goes threw and some kid would come along and have fun so most of my antennas are closer to the house
so Dave you are telling me that I need to set down with the manual to the 7300 hundred . which you have one.
Great job
Interesting video, the only thing it lacks is a panoramic vista at the conclusion.
As always fantastic video. But what can I do in a high rise 16 floor antenna with shack at 14 floor... suffer from noise from the two elevators ?
Just thinking if you have an ICOM 9700 then you have access to an Adaptive Noise Filter so maybe turning it on might kill a lot of the noise.
What do I do if you can't ground the radio. I ask that because to get the grounding wire from my radio outside to the grounding rod would require about about 70ft of grounding wire. I was told a grounding wire should not be that long as it will then turn into an antenna. So how can I ground the radio with such a long grounding wire? Would it least help if I just grounded all the radio equipment to just a copper pipe inside the house without the copper pipe being grounded to the grounding rod outside?
I had to checkout at read the manual LOL
Very good content.
At 9:00 is a good example of ground current causing problems do to Too Many Grounds Not Bonded To The Utility Ground! That is one of the reasons that the ground rod exists other than, as Judge Dred would say: "It's the Law." NEC 810: pslara.org/docs/2.D.pdf
How about a video on active noise suppression?
Dave, on a typical mobile or magmount, the "wind" is high but there's never a ground from the whip element. Should there be one to reduce static and noise?
The coax shield is connected to a metallic plate near the bottom of the mount, which couples to the car roof. The car roof acts as the radial field.
by the way there is much of the 7300 I don't know aboutr.
I've always wondered what the relative effectiveness of the clamp-on split ferrite beads is versus a solid bead, versus looping through a ferrite ring, e.g., how many split beads equal a one loop through a ring? I'm sure it's not a straight forward comparison, but I would still like to get a sense so that I could know if it's worth the extra effort to use rings or can I come close with the easy clamp=ons. 73, Bob, WK2Y
The split ferrities aren't as effective as the bead-type, but are what you can use for systems already in service.
@@davecasler Thanks. I would love to see some numbers at some point. I'll have to Google around. Stay well, stay healthy.
Arthour C Clark ?
Think that's correct.
It's a real shame . The YEARS of tv offender ( ham operators inter fearing with the Jackie Gleason show. Or the tonight show.) You" hear " get out the touches, bring the pitch fork. Mostly caused by my neighbor. He would "smack" the old "Philco©" so hard to shake up the tubes. That it made a raspberry on the local TVs. But is easy to say the ham did it. Ps he banged too often, too hard it flamed out.
Peter PacTOR picked a peck of proper packets............73
I have often had to give my callsign many times because the listener had their DNR turned up so high they couldn't tell Alpha from Oscar! I Do Not like DNR and will not use it except for the last resort. Distorts the intelligibility of the received signal too much.