The fact that neither of the other antennas seem to hear the noise makes me wonder if the hardline on the tower along with the coax jumpers may be part of the problem. Namely, if there happens to be a bad connection (probably the shield) causing noise to leak in. The SWR can read OK but there still could be a questionable connection. This part of "8-Land" is currently in the midst of an ice storm, but when weather improves, the OP may want to take a look at the various connections. Perhaps jumper around the entry panel (from the hardline to the radio} with a known good length of coax.
New tower, unbearable hiss on 2m
- Thread starter N8SHA
- Start date
Indeed, we are thawing out right now and it will be a little while before I can reasonably start checking things again. On this plus side, I didn't get it nearly as bad as the lower part of the peninsula. Very thick hard crust here, compared to the solid ice others got.
Again, all the suggestions are much appreciated. I've lucked out with everything in the past. This is the first time I've run into anything major.
While I'm thawing out, I discovered that Google maps got a shot of the build in progress last summer. So, I marked it up to give some sense of what my setup is.
Red triangles are the antennas, the tower in the upper right. Red lines are grounding & bonding lines.
Yellow is the coax runs and the entry panel
Green is utility power, with a ground mounted transformer across the street. Our power comes from the homes to the south. The wight building to the north belongs to a neighbor to the east and recently got power for the first time.
Orange is cable / internet, the circles are the posts.
Again, all the suggestions are much appreciated. I've lucked out with everything in the past. This is the first time I've run into anything major.
While I'm thawing out, I discovered that Google maps got a shot of the build in progress last summer. So, I marked it up to give some sense of what my setup is.
Red triangles are the antennas, the tower in the upper right. Red lines are grounding & bonding lines.
Yellow is the coax runs and the entry panel
Green is utility power, with a ground mounted transformer across the street. Our power comes from the homes to the south. The wight building to the north belongs to a neighbor to the east and recently got power for the first time.
Orange is cable / internet, the circles are the posts.
mmckenna
I ♥ Ø
I'd probably start looking carefully at your neighbors house to see if they have any devices that are causing the noise.
That is a tricky bit of thin ice you have to walk on, and will depend on how friendly they are.
Asking the to shut off power to see if the noise stops would be an option.
Other option would be to take a 2 meter handheld, remove the antenna, and go (legally) sniffing around the outside of the home and see what you find.
Other would be to start using the 2 meter hand held to sniff around the cable TV/phone lines. Cable TV leakage can cause issues like this. Optical network terminals used by the phone company can spew out noise on 2 meters (I can usually find them while driving around in my truck with the mobile on a 2 meter simplex frequency. I can usually hear them about 50 yards away…)
That is a tricky bit of thin ice you have to walk on, and will depend on how friendly they are.
Asking the to shut off power to see if the noise stops would be an option.
Other option would be to take a 2 meter handheld, remove the antenna, and go (legally) sniffing around the outside of the home and see what you find.
Other would be to start using the 2 meter hand held to sniff around the cable TV/phone lines. Cable TV leakage can cause issues like this. Optical network terminals used by the phone company can spew out noise on 2 meters (I can usually find them while driving around in my truck with the mobile on a 2 meter simplex frequency. I can usually hear them about 50 yards away…)
This is a bit baffeling. No unmute in spite of strong signal.
What does the noise sound like when you unmute the radio, any worse than other ambient noise.
That might indicate internally gennerated noise. self generating feedback in the front end. (self oscilating)
I have an Icom so bad with that, I put the Icom away. A Kenwood and a commercial Harris doesnt do that.
Cable, even digital, has a service carrier used to find bad connections. That is usually just above FM broadcast.
I worked with that 5/8 heliax too and that takes the right tools to install connectors, or your connectors can be faulty. something like a Nano Vna can test that and the antenna system.
Obvious there is a difference between your two Diamond antenna's.
What does the noise sound like when you unmute the radio, any worse than other ambient noise.
That might indicate internally gennerated noise. self generating feedback in the front end. (self oscilating)
I have an Icom so bad with that, I put the Icom away. A Kenwood and a commercial Harris doesnt do that.
Cable, even digital, has a service carrier used to find bad connections. That is usually just above FM broadcast.
I worked with that 5/8 heliax too and that takes the right tools to install connectors, or your connectors can be faulty. something like a Nano Vna can test that and the antenna system.
Obvious there is a difference between your two Diamond antenna's.
Any luck looking with a spectrum display? (Either spectrum analyzer, or from an SDR?)
dickie757
Wired
I would swap the x50s for each other. And, how does the yagi get into the house? Does it go into a switch in the shack?
FKimble
Member
Whats on the roof of the barn? Almost looks like solar panels?
Is the interference 24/7>
Frank
Is the interference 24/7>
Frank
So, it's been ... a while... still trying to work through the problem. I ran things through a RigExpert AA-600 and the RX plot looks odd. I just don't know how to interpret it though. Soomed out as far as possible, still clips. SWR is fine (1.5:1 or less) across the band, nothing supicious in the TDR plot.
G7RUX
Member
- Joined
- Jul 14, 2021
- Messages
- 387
If I'm understanding this correctly, you are having this noise issue on the vertical on the tower but *not* the yagi on the tower? Is the yagi horizontally polarised? I'm assuming it is... Are they separate feeders or switched antennas with the one feeder?
So the noise is *not* present on the other vertical nearby on the house...unlikely to be a strong interfering or intermod-ing transmitter nearby otherwise you might expect to seee the same issue on the both antennas.
If the noise is on one antenna and the feeders are shared then I would suggest it is an ioncoming signal of some sort. If the feeders are not shared then there *may* be an issue with the feeder but that would require a lot of digging into.
To be honest, my best guess without more information would be that something is close-coupling into that vertical antenna...
Edit: apologies, I hadn't seen the replies talking about power already.
Further point, can you find the noise on a 2m handheld or a scanner?
Eureka....!
For those that have been following.... I decided to perform the power down the entire house test again. Thinking back, I realized I had left a battery backup on during the last attempt. Success! Powering things on one by one and going back through I was able to narrow it down to a POE / IP Camera. I'm not sure if it is the camera or power injector right now, but removing those from the system has fixed the issue on 2m. It's clear as a bell now.
Thanks for all of the help and suggestions. It has certainly been a learning experience.
Matt
For those that have been following.... I decided to perform the power down the entire house test again. Thinking back, I realized I had left a battery backup on during the last attempt. Success! Powering things on one by one and going back through I was able to narrow it down to a POE / IP Camera. I'm not sure if it is the camera or power injector right now, but removing those from the system has fixed the issue on 2m. It's clear as a bell now.
Thanks for all of the help and suggestions. It has certainly been a learning experience.
Matt
Good news! I had an issue with a power injector for my DirecTV satellite dish. It wiped out HF from about 2 MHz to 15 MHz. Had to shut down the power to the house and disable my UPS's to find it.
