[digitalradio] Re: Noise
A couple of things from experience... First, cable internet service does use HF frequencies. I forget which direction is down there, but one is. Second, your power company is a rare find these days. Ten years back it seems most truimmed the fixit guys to cut expenses. I've gone thru it with two power companies now. Time was when all power companies did just that, look for problems. If it is an insulator breaking down, for example, that's current being spent that isn't being billed to anyone. Add up enough of it and its real money to them. but wideband noise like that may not be power company related. Here at my place I've had that now for a few years, making HF pretty useless. But don't discount wall warts. Most of them now are switchers, and make lots of noise. Just not wideband constant level noise so much. And since the energy bill last year, more to come, the feds now mandate efficiency of those things. My two cents. GeorgeC W2DB
Re: [digitalradio] Re: Noise
It is usually so, but there are also return channels to the headend below 54 MHz in some places. A loose conector or a broken shield might allow it to leak out. 73, Jose, CO2JA -- John Taylor escribió: Ron, as a semi direct answer to your question, as a general rule cable tv frequencies typically are well above hf radio. It is not impossible for there to be interference, but generally it will be some other source. One thing to remember with most cable systems is that the line and trunk amps need to be powered and are usualy done through the cable itself with pole mounted power supplies every so often in the system. If there is a connection breakdown somewhere near you, itcould cause your symptoms. You did provide a clue to your own situation. You mentioned a bucket truck in the area when the noise suddenly stopped and then started again. If he was working at a particular pole, you might try physically walking to that pole and see if you hear any arcing, especially if this is also a power pole carrying primary voltages. It is not uncommon for the insulators to start breaking down due to dirt and grime in the air getting on the insulators and forming a path for the current to travel. This manifests itself frequently as strong intermittant static. Your noise blanker typically only works on impulse noise such as ignition, etc. Have you also eliminated all noise sources in your own home, such as televisions, computers and monitors, etc.? A great way to chase the source is to take a small portable shortwave receiver with a small antenna and follow the noise to it's source. You can usually get very close very quickly with a little leg work. Just some thoughts Best of Luck --- In digitalradio@yahoogroups.com, w4lde [EMAIL PROTECTED] wrote: If this question is inappropriate for the reflector I apologize but as of last Friday I started to experience significant noise (S-9) on all bands from 160 through 15M with the lower frequencies much stronger. I thought that it was due to power line noise but it appears to be intermittent in that it completely disappeared last Friday evening but once again showed up last Saturday and stayed this way. On the Ft1000mp the noise blankers are completely ineffective. At the same time I started having internet problems and the cable company indicated they should have the speed issue fixed by Tuesday. The cables are run on poles until they enter a subdivision which then run underground. My question is can cable lines be the possible problem to HF frequencies? The power and cable companies have been installing new poles and running new lines in the area which initially led me to believe it was a power issue however, while I was writing this email the noise completely disappeared for a few seconds and then reappeared. As I was looking out my window I noticed a cable company buck truck through the woods towards the main road, I am off now to talk to them and see what I can discover. Any suggestions? Thanks for the bandwidth if this question is inappropriate for this reflector. 73 de Ron W4LDE Announce your digital presence via our Interactive Sked Page at http://www.obriensweb.com/sked Yahoo! Groups Links -- MSc. Ing. José Angel Amador Fundora Profesor Auxiliar Departamento de Telecomunicaciones Facultad de Ing. Eléctrica, CUJAE Calle 114 # 11901 e/119 y 127 Marianao 19390 Ciudad de la Habana, Cuba Tel: (53 7) 266-3445 Mail: amador at electrica.cujae.edu.cu
[digitalradio] Re: Noise
Hi Ron, Use a portable HF receiver with a whip antenna and walk around, track it down by signal strength. This will find the source 90% of the time. Take 2 ferrites and call me in the morning... Bonnie VR2/KQ6XA --- In digitalradio@yahoogroups.com, w4lde [EMAIL PROTECTED] wrote: I started to experience significant noise (S-9) on all bands from 160 through 15M with the lower frequencies much stronger. Any suggestions? Ron W4LDE
[digitalradio] Re: Noise
Ron, One handy trick, the local 'radio inspcetor' for want of a better name, passed on to me was ... That the closer you get to the noise source .. the higher in frequency you can pick it up .. I had a wide band signal taking all of 145 Mhz out ... finally tracked it down, using a uhf 'tv' ae and my frg9600 tuned round 800 Mhz with the yagi I managed to pin point the problem .. a chattering rely in a large tumble dryer .. the mains cable was raditing ... I spent ages with a hf and mw set but never managed a good fix, signals came from all over G .. --- In digitalradio@yahoogroups.com, expeditionradio [EMAIL PROTECTED] wrote: Hi Ron, Use a portable HF receiver with a whip antenna and walk around, track it down by signal strength. This will find the source 90% of the time. Take 2 ferrites and call me in the morning... Bonnie VR2/KQ6XA --- In digitalradio@yahoogroups.com, w4lde w4lde@ wrote: I started to experience significant noise (S-9) on all bands from 160 through 15M with the lower frequencies much stronger. Any suggestions? Ron W4LDE
[digitalradio] Re: Noise
Ron, as a semi direct answer to your question, as a general rule cable tv frequencies typically are well above hf radio. It is not impossible for there to be interference, but generally it will be some other source. One thing to remember with most cable systems is that the line and trunk amps need to be powered and are usualy done through the cable itself with pole mounted power supplies every so often in the system. If there is a connection breakdown somewhere near you, itcould cause your symptoms. You did provide a clue to your own situation. You mentioned a bucket truck in the area when the noise suddenly stopped and then started again. If he was working at a particular pole, you might try physically walking to that pole and see if you hear any arcing, especially if this is also a power pole carrying primary voltages. It is not uncommon for the insulators to start breaking down due to dirt and grime in the air getting on the insulators and forming a path for the current to travel. This manifests itself frequently as strong intermittant static. Your noise blanker typically only works on impulse noise such as ignition, etc. Have you also eliminated all noise sources in your own home, such as televisions, computers and monitors, etc.? A great way to chase the source is to take a small portable shortwave receiver with a small antenna and follow the noise to it's source. You can usually get very close very quickly with a little leg work. Just some thoughts Best of Luck --- In digitalradio@yahoogroups.com, w4lde [EMAIL PROTECTED] wrote: If this question is inappropriate for the reflector I apologize but as of last Friday I started to experience significant noise (S-9) on all bands from 160 through 15M with the lower frequencies much stronger. I thought that it was due to power line noise but it appears to be intermittent in that it completely disappeared last Friday evening but once again showed up last Saturday and stayed this way. On the Ft1000mp the noise blankers are completely ineffective. At the same time I started having internet problems and the cable company indicated they should have the speed issue fixed by Tuesday. The cables are run on poles until they enter a subdivision which then run underground. My question is can cable lines be the possible problem to HF frequencies? The power and cable companies have been installing new poles and running new lines in the area which initially led me to believe it was a power issue however, while I was writing this email the noise completely disappeared for a few seconds and then reappeared. As I was looking out my window I noticed a cable company buck truck through the woods towards the main road, I am off now to talk to them and see what I can discover. Any suggestions? Thanks for the bandwidth if this question is inappropriate for this reflector. 73 de Ron W4LDE
[digitalradio] Re: Noise
Having experienced something like this last year, a fried eggs sizzling noise I tried many recommendations. BTW, our utilities are underground. Eliminate your house as the source of the problem by running your rig from a battery and shut off the house circuit breakers, everything. Don't overlook a bad PC UPS and poor wall wart power supplies. Ok, maybe the noise is not in your house, now put your hiking boots on and walk the neighborhood with headphones, a FT817 and whip antenna. Someone told me that AM on 138Mhz was best for finding noise, I cannot be sure of that but I sure did find a lot of weird stuff, houses making buzzing noises, street intersections with screeching noises It actually became very interesting and confusing. I put many nights into walking the neighborhood and beyond since none of the noises I heard to date traveled very far. Suddenly the noise at my rig went away and never returned. I can only imagine it was a neighbors electric blanket or fish tank heater ... or maybe something caught fire and burnt itself out. Anyway, I won't miss poking at around houses with the whip to seek out electrical noises. Bill k6acj --- In digitalradio@yahoogroups.com, w4lde [EMAIL PROTECTED] wrote: If this question is inappropriate for the reflector I apologize but as of last Friday I started to experience significant noise (S-9) on all bands from 160 through 15M with the lower frequencies much stronger. I thought that it was due to power line noise but it appears to be intermittent in that it completely disappeared last Friday evening but once again showed up last Saturday and stayed this way. On the Ft1000mp the noise blankers are completely ineffective. At the same time I started having internet problems and the cable company indicated they should have the speed issue fixed by Tuesday. The cables are run on poles until they enter a subdivision which then run underground. My question is can cable lines be the possible problem to HF frequencies? The power and cable companies have been installing new poles and running new lines in the area which initially led me to believe it was a power issue however, while I was writing this email the noise completely disappeared for a few seconds and then reappeared. As I was looking out my window I noticed a cable company buck truck through the woods towards the main road, I am off now to talk to them and see what I can discover. Any suggestions? Thanks for the bandwidth if this question is inappropriate for this reflector. 73 de Ron W4LDE
[digitalradio] Re: Noise Reduction and the digital modes
Hi Andy, Assume you mean DSP noise reduction...have never seen any real effect of note either way on digital modes...even on HELL. The noise blanker degrades some WSJT modes but otherwise have seen little impact on received digital decodes. On Hell, at least Feld Hell, the AGC seems to matter alot moreslower AGC seems to de-blur the received print and reduce screen noise. Interesting question though. 73, Bill N9DSJ --- In digitalradio@yahoogroups.com, Andrew O'Brien [EMAIL PROTECTED] wrote: Noise reduction on my old rig never did much. Now I have a new rig the NR buttons actually appear to do some things. What about noise reduction and the digital modes, is it really helpful? I did just notice that with a Hell QSO NR made the print more blurred. For other modes I have not noticed much other than a lot less speckles in the waterfall. Maybe a graphically empty waterfall helps when a weak signal comes along but i worry the weak signal may get zapped by the NR. Comments ? -- Andy K3UK Skype Me : callto://andyobrien73 www.obriensweb.com
Re: [digitalradio] Re: Noise
I hear it loud and clear in central NC. I heard that ARRL has a person who specializes and spectrum protection and has had good results in the past reporting these problems and following thorugh with the FCC. I do not know who this person is though; it was mentioned in a recent QST article. It sure rips up the PSK31 freqs.. - Original Message - From: mac2251 To: digitalradio@yahoogroups.com Sent: Thursday, July 27, 2006 4:58 PM Subject: [digitalradio] Re: Noise --- In digitalradio@yahoogroups.com, mac2251 [EMAIL PROTECTED] wrote: Anyone know what the signal is on 14071.944 ? It runs about S8 with some qsb, and sounds like high speed clicking noise. Hope its not a local problem. Mike K9HCK Its not Hell altho I did get a nice almost plaid print. It seems to have one main trail with several weaker trails on either side. I hope its not a permanent fixture on that part of the band,it tears up the psk freqs. Mike K9HCK [Non-text portions of this message have been removed] Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[digitalradio] Re: Noise
--- In digitalradio@yahoogroups.com, mac2251 [EMAIL PROTECTED] wrote: Anyone know what the signal is on 14071.944 ? It runs about S8 with some qsb, and sounds like high speed clicking noise. Hope its not a local problem. Mike K9HCK Its not Hell altho I did get a nice almost plaid print. It seems to have one main trail with several weaker trails on either side. I hope its not a permanent fixture on that part of the band,it tears up the psk freqs. Mike K9HCK Need a Digital mode QSO? Connect to Telnet://cluster.dynalias.org Other areas of interest: The MixW Reflector : http://groups.yahoo.com/group/themixwgroup/ DigiPol: http://groups.yahoo.com/group/Digipol (band plan policy discussion) Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/digitalradio/ * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
