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About Carl Blare
Ambassador of Recreational Radio, owner operator of KDX Worldround Radio, webmaster for kdxradio.com, host of The Blare Blog.
Reader Interactions
Comments
MICRO1700says
I Really Enjoyed Episode 13 RFB had more cool info!
By the way Carl, if you go
on 660 kHz, it could be a
daytime only operation. That
way, if anybody was listening
to the Grand Ole Opry (Sp?) on
WSM next door, your signal
wouldn’t bother them, because your 660 rig
would be on during the day only.
You could rig up something so that
the 660 transmitter has it’s own
special sign-on and sign-off. That
would be fun.
By the way, WSM 650 comes in great
up here in Connecticut.
Bruce, Dog Radio Studio 2
ABMedia1says
LPH On KDSX! carl mention me and my station on carrier current and why i have a good coverage. i bought a cheap $20 fm car transmitter, and i opened it up messed with the circuits and modified it too. and on a good clear day it can be heard up to 1/4 of a mile away, and in the night time on a clear night it can be heard up to a mile away, but on a bad day cloudy/off kind of day it goes only about 3-5 blocks to a 1/8 of a mile away. it just depends what kind of day it is outside (weather or interfearence wise).
Carl Blaresays
To Be Safe The coverage sounds good for just $20 but the most important safety tip is to find a way to check the upper harmonics up above the FM band, from 108 to I think 176mHz, which is the aviation band. If traffic control towers or airplanes hear your station you will get a knock on the door.
I have a Alinco DJ-X3 hand-sized communications radio that tunes from below the AM band all the way up into the gigaHertz, and I can check the aviation band to see how far my harmonics go. Not very far, but I’m running plain C.Crane and Wholehouse transmitters, which are as weak as a dry spit. (That’s good. I just thought of that)
Safe fun lasts longer.
ABMedia1says
a friend of mine mentioned about that a friend of mine mentioned about that. and with his special receiver he wasnt able to pick up anyting in that band so, he said i was good to go. im glad you mentioned that carl.
RFBsays
Experiments with FM CC VHF can be sent down the power lines, but not very efficiently due to the very short wavelength versus the very low inductance of the lines. This is why it would take some power of significant level to really get the signal down the “pipe” as it were.
BPL’s use frequencies well up into 80Mhz and are transmitted down the “high” side of the utility. IE on the 7KV-30KV lines prior to the step down transformers. So it is understandable that 88.7 can get in there too and do some good on the power lines.
The harmonics issue is crucial here considering your signal just might go into a nearby power line feeding an airport communications shack! Always keep in mind worse case scenarios and build the system to avoid any possible problems.
I think its fantastic your FM is working that well on the power line. I have dabbled with it and had good results with experimenting CC FM. However we must now look at the rulebook and note a couple of crucial points.
Part 15.239 clearly states 250uV/M @ 3m from radiating element. This can be an antenna, or a wire, or leaky coax.
This means that anywhere along the run of the power line or leaky coax or single wire, that signal cannot exceed the 250uV/m @3m limit..period. The signal can go as far as it can “DOWN” the line and into homes and businesses, but it CANNOT travel “OFF” the wire any further than what is expected off the wire antenna of a C-Crane or whip antenna of a Decade or other.
It is the same concept with CC AM. Except that the distances with CC AM signal coming “OFF” the wire (radiated emission) is much further because of the wavelength, which is much longer than VHF.
Just be safe working around that breaker box or power outlet. Use proper coupling techniques or couplers designed for the frequency band your working. They not only provide maximum transfer of RF energy onto the lines, but also provide isolation between you, your equipment, your TX from the dangerous and deadly voltages on those lines.
And always remember folks….no matter if its CC AM or CC FM…those lines, even the neutral line especially, are subject to being struck by lightning. And even though the power company takes great steps to ensure the bulk of a lightning strike will dump to ground at the poles or drop, some of that can still induce deadly voltage spikes down the lines right into your stuff. It sure is better to have a few fuses blow on the coupler than to have some of that spark jump across some silly capacitor or inductor coil and go into everything connected to that TX.
AT KPEJ Ch 24 in Odessa Tx, back in 1994 during a severe lightning storm, the tower was directly hit by lightning and knocked a 600 amp 3 phase power surge protector box right off its mounts on the wall and threw it across the room. The lightning hit the tower, not the power pole.
So this should give you an idea of what lighting can do and will do unexpectedly.
RFB
ABMedia1says
I Can Get 650 WSM, 850 KOA, 1130 KWKH. I Can Get 650 WSM, 850 KOA, 1130 KWKH, The Best Signal on my am radio receiver in North Texas, crystal clear.
MICRO1700says
Radio Stations Yup, as I said, WSM comes in here well
at night.
One night years ago here in Connecticut,
I had 850 kHz on, and KOA 850, Denver,floated up
above the jumble, and gave a clear ID.
I have also heard KOA in San Fransisco, CA.
I’ve tried to hear KWKH 1130, here in Connecticut,
but no such luck. I believe it’s pattern
doesn’t favor the east coast.
Bruce, Dog Radio Studio 2
ABMedia1says
I Think KWKH is Directional @ Night and broadcasts in stereo I Think KWKH is Directional @ Night and broadcasts in stereo, i think, KOA Is in HD and im not sure about WSM and what they broadcast in, i listen to KWKH at night they play the best Classic Country Music in the world of AM Radio. Keep It Country Bossier City! Lol!
MICRO1700says
KWKH That’s great that KWKH plays music
at night that you enjoy. Not too many
people get that out of AM radio anymore.
I Really Enjoyed Episode 13
RFB had more cool info!
By the way Carl, if you go
on 660 kHz, it could be a
daytime only operation. That
way, if anybody was listening
to the Grand Ole Opry (Sp?) on
WSM next door, your signal
wouldn’t bother them, because your 660 rig
would be on during the day only.
You could rig up something so that
the 660 transmitter has it’s own
special sign-on and sign-off. That
would be fun.
By the way, WSM 650 comes in great
up here in Connecticut.
Bruce, Dog Radio Studio 2
LPH On KDSX!
carl mention me and my station on carrier current and why i have a good coverage. i bought a cheap $20 fm car transmitter, and i opened it up messed with the circuits and modified it too. and on a good clear day it can be heard up to 1/4 of a mile away, and in the night time on a clear night it can be heard up to a mile away, but on a bad day cloudy/off kind of day it goes only about 3-5 blocks to a 1/8 of a mile away. it just depends what kind of day it is outside (weather or interfearence wise).
To Be Safe
The coverage sounds good for just $20 but the most important safety tip is to find a way to check the upper harmonics up above the FM band, from 108 to I think 176mHz, which is the aviation band. If traffic control towers or airplanes hear your station you will get a knock on the door.
I have a Alinco DJ-X3 hand-sized communications radio that tunes from below the AM band all the way up into the gigaHertz, and I can check the aviation band to see how far my harmonics go. Not very far, but I’m running plain C.Crane and Wholehouse transmitters, which are as weak as a dry spit. (That’s good. I just thought of that)
Safe fun lasts longer.
a friend of mine mentioned about that
a friend of mine mentioned about that. and with his special receiver he wasnt able to pick up anyting in that band so, he said i was good to go. im glad you mentioned that carl.
Experiments with FM CC
VHF can be sent down the power lines, but not very efficiently due to the very short wavelength versus the very low inductance of the lines. This is why it would take some power of significant level to really get the signal down the “pipe” as it were.
BPL’s use frequencies well up into 80Mhz and are transmitted down the “high” side of the utility. IE on the 7KV-30KV lines prior to the step down transformers. So it is understandable that 88.7 can get in there too and do some good on the power lines.
The harmonics issue is crucial here considering your signal just might go into a nearby power line feeding an airport communications shack! Always keep in mind worse case scenarios and build the system to avoid any possible problems.
I think its fantastic your FM is working that well on the power line. I have dabbled with it and had good results with experimenting CC FM. However we must now look at the rulebook and note a couple of crucial points.
Part 15.239 clearly states 250uV/M @ 3m from radiating element. This can be an antenna, or a wire, or leaky coax.
This means that anywhere along the run of the power line or leaky coax or single wire, that signal cannot exceed the 250uV/m @3m limit..period. The signal can go as far as it can “DOWN” the line and into homes and businesses, but it CANNOT travel “OFF” the wire any further than what is expected off the wire antenna of a C-Crane or whip antenna of a Decade or other.
It is the same concept with CC AM. Except that the distances with CC AM signal coming “OFF” the wire (radiated emission) is much further because of the wavelength, which is much longer than VHF.
Just be safe working around that breaker box or power outlet. Use proper coupling techniques or couplers designed for the frequency band your working. They not only provide maximum transfer of RF energy onto the lines, but also provide isolation between you, your equipment, your TX from the dangerous and deadly voltages on those lines.
And always remember folks….no matter if its CC AM or CC FM…those lines, even the neutral line especially, are subject to being struck by lightning. And even though the power company takes great steps to ensure the bulk of a lightning strike will dump to ground at the poles or drop, some of that can still induce deadly voltage spikes down the lines right into your stuff. It sure is better to have a few fuses blow on the coupler than to have some of that spark jump across some silly capacitor or inductor coil and go into everything connected to that TX.
AT KPEJ Ch 24 in Odessa Tx, back in 1994 during a severe lightning storm, the tower was directly hit by lightning and knocked a 600 amp 3 phase power surge protector box right off its mounts on the wall and threw it across the room. The lightning hit the tower, not the power pole.
So this should give you an idea of what lighting can do and will do unexpectedly.
RFB
I Can Get 650 WSM, 850 KOA, 1130 KWKH.
I Can Get 650 WSM, 850 KOA, 1130 KWKH, The Best Signal on my am radio receiver in North Texas, crystal clear.
Radio Stations
Yup, as I said, WSM comes in here well
at night.
One night years ago here in Connecticut,
I had 850 kHz on, and KOA 850, Denver,floated up
above the jumble, and gave a clear ID.
I have also heard KOA in San Fransisco, CA.
I’ve tried to hear KWKH 1130, here in Connecticut,
but no such luck. I believe it’s pattern
doesn’t favor the east coast.
Bruce, Dog Radio Studio 2
I Think KWKH is Directional @ Night and broadcasts in stereo
I Think KWKH is Directional @ Night and broadcasts in stereo, i think, KOA Is in HD and im not sure about WSM and what they broadcast in, i listen to KWKH at night they play the best Classic Country Music in the world of AM Radio. Keep It Country Bossier City! Lol!
KWKH
That’s great that KWKH plays music
at night that you enjoy. Not too many
people get that out of AM radio anymore.
Bruce, Dog Radio Studio 2