Static Conditions

[nickcarr]

Anyone else getting really bad static conditions for HF last few days?

[ka3jjz]

Lots of possibilities here - bad solder joint, water in the coax, local noise production (faulty insulators on an electrical pole can do this) - time for a little detective work. It may not just be 'conditions'.

73 Mike

[brandon]

Is this by any chance on 5 and 6 MHz?
There is something transmitting (presumably from the Asian continent) that can wipe out a large portion of the 5 and 6 MHz aero bands. At first I thought it was local noise, but I was using a receiver on GlobalTuners located in Brisbane and it had the exact same interference! Only hear it around local sunrise. I will try to record it next time since it's hard to explain in words.

[nickcarr]

Nah it's nothing technical Mike - at least I'm 99% certain that it isn't. We've had really nice weather for several days with no moisture. It just seems like off-peak range - so at night from 6-30mhz - has an unusual 'static' attached to it. It sounds like increased white noise in SSB but in AM you can definitely hear it. I think it started like Thursday-ish.

It does sound somewhat artificial... I just hope my neighbors haven't put up something recently. I checked my local vicinity for the noise and it's nothing in my room.

One example: I was trying to cruise CB frequencies and usually I get a very low noise floor. Last night the noise floor was so high that I couldn't distinguish anything...

I should point out that the static disappears with a strong AM signal (like a BCB station.)

If it still hear it tonight, I'll take out the Sony 7600gr and do a walk around outside near the antenna and see if I hear it there.

~

Brandon, I don't hear anything in that range, but in the range of 4.4-4.8 is very tough due to some kind of radar. I'm not sure if it's OTHR or something else but you can hear a pulsating noise (in USB) - it's very strong here 24/7 and especially at night.

[KT4HX]

I would say the radar you're referring to is CODAR. When I've been in the Caribbean it was horrendous in the 60 meter band. I also hear it here in Va.

Originally Posted by nickcarr

Brandon, I don't hear anything in that range, but in the range of 4.4-4.8 is very tough due to some kind of radar. I'm not sure if it's OTHR or something else but you can hear a pulsating noise (in USB) - it's very strong here 24/7 and especially at night.

[nickcarr]

Ah thanks Alan. Yes, I went to their web site. Interesting technology but they screw up my SWL hobby!

[k9rzz]

The term "static" by itself doesn't really describe anything, you've got to be more specific.

Here's my two cents:

Thunderstorms produce "static crashes".
Powerlines create "powerline buzz"
Electronics create "birdies" or I guess electric motors cause "whine".
If you've got some BIG antennas, rain can give you an elevated noise floor.
Sidebands from loud stations on nearby frequencies can cause "splatter".
Digital transmissions create "hash".

They all have a different sound so you should be able to tell the source in general.
Finding the specific place might be hard though!

[nickcarr]

As of tonight, the "static" is gone. And yes, that's the best term for it. It's not a buzzing noise and it doesn't sound like interference. It literally sounded like 'static' on AM.

I haven't changed a thing and it disppeared, so I'm not sure what to make of it. In fact, the upper AM bands (after dark) were very quiet. I was hearing nothing but clean white noise.

Hopefully it will stay that way.

[brandon]

Originally Posted by KT4HX

I would say the radar you're referring to is CODAR. When I've been in the Caribbean it was horrendous in the 60 meter band. I also hear it here in Va.

Here is an audio sample of the noise that sometimes wipes out parts of the aero bands.
Audio Sample: SSB Mode | AM Mode
These were recorded this morning on 5320. Some days it moves higher in the 5500-5700 range.

Originally Posted by nickcarr

Brandon, I don't hear anything in that range, but in the range of 4.4-4.8 is very tough due to some kind of radar. I'm not sure if it's OTHR or something else but you can hear a pulsating noise (in USB) - it's very strong here 24/7 and especially at night.

Is this what you are hearing? This was recorded as heard on 4666 kHz.
4666 kHz Sweeping Noise

[markclark]

I've had really lousy atmospheric conditions for about the last four nights. Lots of static and generally weak signals form the mid-east, Europe and South Pacific.

[nickcarr]

Originally Posted by brandon

Here is an audio sample of the noise that sometimes wipes out parts of the aero bands.
Audio Sample: SSB Mode | AM Mode
These were recorded this morning on 5320. Some days it moves higher in the 5500-5700 range.

Wow that's really bad. No, I don't think I've heard that up my way. I generally listen to 5547 and 5574 and haven't heard that. I'll try tuning down a bit though. See if I can hear it.

Is this what you are hearing? This was recorded as heard on 4666 kHz.
4666 kHz Sweeping Noise

Yep! That's it precisely. It sounds a bit louder on my end. It wipes out the mid 4khz range.

[nickcarr]

Well, after today's mess I definitely am seeing some strange local EMI. The question is from where. I believe the "static" I was hearing was a symptom of a much bigger problem.

Off and on the last few days, I've had the entire DC to 30mhz+ band infected with this "static" but it's no longer "static" - it's now a pulsing interference kind of static. It's definitely not from my local house vicinity.

I took out the Sony 7600GR and walked my perimeter and the signal is strong. I'm looking into constructing an EMI loop probe - which should give me some directivity. I've found several designs online and it seems fairly straight forward. I've been scouring the ARRL web site as well for information on "common" inteference types. It's interesting to learn what kind of devices can give off so much EMI - but it seems like AC transformers/AC power poles are the worst culprits.

I started to take some notes down tonight and suddenly at 1:15am local time the noise almost vanished. I'm listening at 20mhz and the noise dropped from S9 to S1-S3. I'm getting a random spark every few secs at S3-S4 but not a "steady" noise like before. (Preamp is OFF by the way.)

When the noise stops briefly you can hear how quiet 20mhz can be... it's quite drastic.

I'm going to be reading up on the current literature on EMI sources and how to track them down.

Thankfully, the noise is such that it doesn't "wipe out" the band - like some of the reports I've read. (Some people couldn't even pick up local AM broadcasts! Now that is bad!)

[LarrySC]

Seems everyone has static problems at one time or another. I have a 66' Windom cut 24'x42' feed with RG-59 and a Vertical 17' mounted on a 20' mast 1' in the ground. Yaesu 8800 with aux tuner. I must switch from wire to Vert to get away from my static which is High Tension Power Lines 1/4 mile either side of my location coming from a Duke Nuclear station. During the summer the static spikes all up and down the band caused by the load on their system and if you look at it on a scope and close down the bandwidth it looks like a picket fence. Been round and round with the power co. The 3 MHz to 7 MHz band changes alot this time of the year hear on the East Coast of US. Last weeks band opening was GREAT. Good DX to all.

[bluefox2163]

10.051 khz seems to be pretty messed up wiyh static ,and to me it seems conditions have been lousy,does anyone know if it might get better as far as propagation goes in the next couplo years

[LarrySC]

Pray for sunspots..............!!

[kb2vxa]

Maybe you can buy air time on WWCR and hold a prayer service? Too bad I lost the recording I made back in the 60s when a bunch of hippies surrounded the Pentagon chanting OUT DEMONS OUT!

I wonder if any of you remember that. (;->)