Home |
Search |
Today's Posts |
|
#1
![]() |
|||
|
|||
![]()
80 is basically useless. 3400 and 4000 I have a Pegged meter WFM signal
from 1380kc station here. I have mini harmonics ever 200kc that basically makes 80meters unusable Its really annoying and the station says they had their equipment recertified 2 months ago Is there a place I can report this in the FCC? The antenna is about 10 miles from me. And they are running 5kw. They are planning and have approval for 50KW now and Im worried that 160 and 80 and possibly 40 could me useless. Thanks Scotty W7PSK. |
#2
![]() |
|||
|
|||
![]()
R. Scott wrote:
80 is basically useless. 3400 and 4000 I have a Pegged meter WFM signal from 1380kc station here. I have mini harmonics ever 200kc that basically makes 80meters unusable Its really annoying and the station says they had their equipment recertified 2 months ago Is there a place I can report this in the FCC? The antenna is about 10 miles from me. And they are running 5kw. They are planning and have approval for 50KW now and Im worried that 160 and 80 and possibly 40 could me useless. Thanks Scotty W7PSK. You can simply send a letter to the FCC in Washington DC. However there might not be anything they can do. Some years ago a radio station in Marion IN was causing interferance to amateur radio ops in the area. It seemed that there was a spur that fell in the middle of the affected ham band. When the FCC inspected the instalation they measured the spur and determined that it was below the maximum power limit for such emissions. The result was the hams had to suffer due to a totally legal emission. Dave WD9BDZ |
#3
![]() |
|||
|
|||
![]()
"R. Scott" ) writes:
80 is basically useless. 3400 and 4000 I have a Pegged meter WFM signal from 1380kc station here. I have mini harmonics ever 200kc that basically makes 80meters unusable Its really annoying and the station says they had their equipment recertified 2 months ago This is hardly an antenna issue. You do realize that it may not be the transmitter? If your receiver (and you don't specify what it is) hasn't got good strong signal-handling, the station may be overloading it and causing the junk. And at first glance, it wouldn't be obvious whether it's the receiver or the transmitter. Try a different receiver. Put an attenuator between your receiver and antenna, and see what happens to those signals when you increase attenuation. If it's overloadig, there will be a point where the unwanted signals go away that can't be accounted for by the actual attenuation. Borrow a spectrum analyzer, which should stand up well to strong signals since it wouldn't be much use otherwise, and see what signals are arriving at your antenna. If you do see signals that are traceable to the broadcast station, then likely they do have a problem. But if not, it's your receiver. And it may not even be the receiver. There could be something acting as a rectifier, that is picking up the transmiter signal and generating harmonics for your receiver to pickup. A rusty rain gutter, or a bad connection on an antenna, obviously something nearby. You have no reason to doubt the station's word, especially since they do have the rules to follow, and likely are in a worse position than a ham with a bad signal. You are expecting the transmitter to blame because you can't imagine your receiver is at fault. But until you can actually rule out the latter, you have no real reason to blame the transmitter. Michael VE2BVW Is there a place I can report this in the FCC? The antenna is about 10 miles from me. And they are running 5kw. They are planning and have approval for 50KW now and Im worried that 160 and 80 and possibly 40 could me useless. Thanks Scotty W7PSK. |
#4
![]() |
|||
|
|||
![]()
Michael Black wrote:
You do realize that it may not be the transmitter? If your receiver (and you don't specify what it is) hasn't got good strong signal-handling, the station may be overloading it and causing the junk. And at first glance, it wouldn't be obvious whether it's the receiver or the transmitter. Excellent suggestion. Try a high pass filter passing everything above 1710 to see if you have an improvement. At least then you will have a good indication if it is a problem of receiver overloading or not ... If you are using a transceiver as opposed to a separate receiver/xmitter (I know, I am an OT) you can use an rf switch to cut out the filter on xmit to "cure" the problem. Regards, JS |
#5
![]() |
|||
|
|||
![]()
Why all this stuff about "high pass filters" and such. You are dealing with
a spot frequency, not a band of frequencies. A simple parallel resonant notch filter should do the job quite nicely and still pass everything from DC to daylight except that spot frequency. Jim |
#6
![]() |
|||
|
|||
![]()
On Wed, 24 Jan 2007 08:49:21 -0800, "RST Engineering"
wrote: Why all this stuff about "high pass filters" and such. You are dealing with a spot frequency, not a band of frequencies. A simple parallel resonant notch filter should do the job quite nicely and still pass everything from DC to daylight except that spot frequency. Hi Jim There's not much more effort in completely covering a band of problems with a band reject (high pass) filter. The original poster could discover the NEXT broadcaster creating problems when he limited his suppression to the first one. Who needs a chain of notch filters when one would work as well for the entire band? 73's Richard Clark, KB7QHC |
#7
![]() |
|||
|
|||
![]()
Because he's got a SINGLE frequency interfering with his station. To hell
with covering the entire band. A single parallel resonant network will do something in the order of 80 dB of rejection if the L and C are at LEAST something reasonable for Q. Care to calculate the order of filter that will do 80 dB as a low pass filter? And the Q of the components necessary to make the insertion loss negligible at 160 meters? Jim "Richard Clark" wrote in message ... On Wed, 24 Jan 2007 08:49:21 -0800, "RST Engineering" wrote: Why all this stuff about "high pass filters" and such. You are dealing with a spot frequency, not a band of frequencies. A simple parallel resonant notch filter should do the job quite nicely and still pass everything from DC to daylight except that spot frequency. Hi Jim There's not much more effort in completely covering a band of problems with a band reject (high pass) filter. The original poster could discover the NEXT broadcaster creating problems when he limited his suppression to the first one. Who needs a chain of notch filters when one would work as well for the entire band? 73's Richard Clark, KB7QHC |
#8
![]() |
|||
|
|||
![]() "Michael Black" wrote in message ... "R. Scott" ) writes: 80 is basically useless. 3400 and 4000 I have a Pegged meter WFM signal from 1380kc station here. I have mini harmonics ever 200kc that basically makes 80meters unusable Its really annoying and the station says they had their equipment recertified 2 months ago This is hardly an antenna issue. I know, but I thought it might be for them or me, so I came here (one of the only groups I subscribe to) You do realize that it may not be the transmitter? Possibly, but You never know, it might have to do with their plans on moving the antenna and upping power or the recent storms we've had. If your receiver (and you don't specify what it is) hasn't got good strong signal-handling, the station may be overloading it and causing the junk. And at first glance, it wouldn't be obvious whether it's the receiver or the transmitter. ICOM 706MKIIG ... Never had a problem in the 2 years Ive owned it, havnt changed anything at my end. Try a different receiver. Ill see what I can find to use, good idea. Borrow a spectrum analyzer, which should stand up well to strong signals since it wouldn't be much use otherwise, and see what signals are arriving at your antenna. If you do see signals that are traceable to the broadcast station, then likely they do have a problem. But if not, it's your receiver. Ill see if I can find one And it may not even be the receiver. There could be something acting as a rectifier, that is picking up the transmiter signal and generating harmonics for your receiver to pickup. A rusty rain gutter, or a bad connection on an antenna, obviously something nearby. only happend in the last month or two the Big clues that make me wonder is if it was a pure Birdie wouldnt it still be AM rather that Wide FM ? Makes me wonder if the TX is FMing some how. You have no reason to doubt the station's word, especially since they do have the rules to follow, and likely are in a worse position than a ham with a bad signal. You are expecting the transmitter to blame because you can't imagine your receiver is at fault. But until you can actually rule out the latter, you have no real reason to blame the transmitter. I used to work at a Station and I know the rules they have to follow, I also know that very shoddy work is done at a lot and just signed off. Ill continue to check my end, but If Ive never heard the birdies before with the same station (Save the 706MKIIG and new coax on occasion) Ive had for 18 years here with no problems until the recent storms and the station has multiple birdies and its in Wide FM rather than AM ... makes me wonder. Scotty W7PSK |
#9
![]() |
|||
|
|||
![]()
On Wed, 24 Jan 2007 16:49:41 GMT, "R. Scott"
wrote: it might have to do with ... recent storms we've had. Hi OM, Corrosion is a classic distortion products source that could easily bring the problems you see. 73's Richard Clark, KB7QHC |
#10
![]() |
|||
|
|||
![]() "R. Scott" wrote in message ... with no problems until the recent storms and the station has multiple birdies and its in Wide FM rather than AM ... makes me wonder. go mobile. use a small antenna and an attenuator, maybe the one in the rig will be enough with just a 6" antenna or something like that. if it is indeed local to your shack it should be obvious when you get a few blocks away, then start hunting for rectifiers. it should also be obvious if it is from the transmitter as you drive around it. that might also find it if it happens to be from a 3rd party, like a bad ground wire on a power pole or something. Also, do the test of shutting off everything at the breakers in the house... there is an outside chance, especially with the FM symptom and extreme width, that the AM station is getting picked up by some other device and modulating it... it could be getting into a TV and modulating the color burst, or a computer monitor, a old cordless phone, etc. also check their fundamental and see if you can detect the fm on it, that should be obvious enough also and something you could go demonstrate to the engineer that may show him they have a problem that developed after their certification. |
Reply |
|
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
Ohio/Penn DX Bulletin #746 | Dx | |||
Ohio/Penn DX Bulletin #746 | General | |||
Ohio/Penn DX Bulletin #721 | General | |||
Ohio/Penn DX Bulletin #716 | General | |||
Ohio/Penn DX Bulletin #699 | General |