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Post by Admin on Dec 24, 2017 18:13:59 GMT
I have a two story garage and decided to turn the upstairs into my "man den" instead of a wood working shop.
Finishing the room didn't take very long but moving and putting everything back together has just been frustrating at best.
Everything was put into boxes and bins and relocated to the new room and most of it is still in bins.
Well, it took almost a year but I have my carrier current station back online.
A Radio Systems Phase II 20 watt capable transmitter using an LPB TCU-30 coupler connected for neutral injection.
The studio is upstairs, the transmitter and coupler are mounted on the wall downstairs. An 8 foot ground rod directly outside serves as the isolated ground required for neutral injection. A cable runs from the coupler output direct to the garage electrical panel for connection to the service neutral. There is a separation of about 22 feet between the isolated ground and the electrical panel ground. That should provide adequate impedance separation such that there is not an RF short between the two ground points.
When first powered up the transmitter was set at 10 watts. The SWR tuned down to 1.5:1 and the signal sounded fairly clean.
Then my wife said "the internet is down." Ooops, I guess the UVerse VDSL modem doesn't like RF. A quick internet search verified that.
Sweating bullets figuring the modem was blown out, I shut off the transmitter and rebooted the modem. It took almost 15 minutes but the internet connection came back to normal.
So, I reduced the power to 5 watts and crossed my fingers - no problem. The modem seems happy and the transmitter signal sounds good.
Now the field testing starts to find out what kind of range the station has.
Time permitting, I'll post some pictures of the installation along with range reports.
Finally, MRAM 1500 is back on the dial.
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Post by Deleted on Dec 24, 2017 18:36:59 GMT
Right Man for the Job
For most of us the kind of problem you found (Bob) would have taken several weeks to figure out, but you are a man of many skills and were quickly able to know where to look and what to do as soon as a problem arose.
Back when I had DSL it took months to realize that the modem utilizes a band of frequencies that includes most of our medium wave radio band, and a nearby 5 kW AM station was putting strong RF the phone line that messed up my DSL most of the time.
AT&T, the phone line provider, didn't want to hear about it because my actual DSL account was with Earthlink, which has no local offices.
Earthlink, through semi-linqual service people in India, stuck with the claim that "It is your computer" and never corresponded with AT&T on my behalf.
Fortunately cable internet solved all that and life has been excellent ever since, but the experience was certainly informative.
Now I need to get carrier current back on the air.
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Post by Boomer on Dec 24, 2017 20:49:28 GMT
Good for you Bob, I think having both antenna and carrier current systems is nice, they compliment each other. The antenna powered system works for cars outside, a more consistent signal along the roadways, where carrier puts a good signal into neighbor's homes, sneaking in by the wiring, where signals from stations with antennas are apt to be weaker.
I've found it's good to get the SWR down to the minimum possible and got a better match with capacitors across the output, a few hundred pf did it.
I'd like to see Carl get on from his man cave too, love the technology!
Boomer
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Post by Deleted on Dec 24, 2017 21:29:58 GMT
Repair of Carrier Current is Planned
Just this morning I was looking at the 5-Watt LPB Transmitter that needs re-tuning from 1510 kHz to 970 kHz, and not long ago I made a purchase order of all the electrolytics to fix the LPB 2-20 Transmitter.
Also, I have 3-couplers, but will only need one, so at least that will not slow things down.
Boomer said: "I'd like to see Carl get on from his man cave too, love the technology."
Early in 2018 KDX will be on the power wires!
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Post by jimhenry2000 on Dec 28, 2017 7:03:12 GMT
Good troubleshooting Bob! I know next to nothing about carrier current broadcasting. Where can I find more info and products to get my station on carrier current? Also, I believe that it will not go through transformers, and I have one from the power company about 30 yards from my home as my driveway is about 900 feet from street to house. Will that transformer block the signal? Thanks. Jim I have a two story garage and decided to turn the upstairs into my "man den" instead of a wood working shop. Finishing the room didn't take very long but moving and putting everything back together has just been frustrating at best. Everything was put into boxes and bins and relocated to the new room and most of it is still in bins. Well, it took almost a year but I have my carrier current station back online. A Radio Systems Phase II 20 watt capable transmitter using an LPB TCU-30 coupler connected for neutral injection. The studio is upstairs, the transmitter and coupler are mounted on the wall downstairs. An 8 foot ground rod directly outside serves as the isolated ground required for neutral injection. A cable runs from the coupler output direct to the garage electrical panel for connection to the service neutral. There is a separation of about 22 feet between the isolated ground and the electrical panel ground. That should provide adequate impedance separation such that there is not an RF short between the two ground points. When first powered up the transmitter was set at 10 watts. The SWR tuned down to 1.5:1 and the signal sounded fairly clean. Then my wife said "the internet is down." Ooops, I guess the UVerse VDSL modem doesn't like RF. A quick internet search verified that. Sweating bullets figuring the modem was blown out, I shut off the transmitter and rebooted the modem. It took almost 15 minutes but the internet connection came back to normal. So, I reduced the power to 5 watts and crossed my fingers - no problem. The modem seems happy and the transmitter signal sounds good. Now the field testing starts to find out what kind of range the station has. Time permitting, I'll post some pictures of the installation along with range reports. Finally, MRAM 1500 is back on the dial. |
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Post by Boomer on Dec 28, 2017 11:57:38 GMT
It's funny when you think about it Carl, wireless on the wires. LPB's own literature has described it as a sort of cable radio system, and it is kind of an indirect one, in that listeners don't intend to pick up something off the line, it just happens as part of the process.
I'd think carrier current is nice, because it's more stealth, no antennas to place blame on by neighbors, no one looking from outside would know you have a radio station.
I haven't had trouble with my modems or other equipment in the house, but I use a transformer method of coupling that I came up with several years ago, the primary is one turn through the transformer, and the power line itself is the secondary, and there's no 60 hz AC line power in my coupler. The power ground to the breaker box and other grounds are the 'ground return' side, and the high side is the wires going out to the pole, so I'm pushing most of the power out to the street on both phases plus the neutral.
Jim Henry 2000, pole pig transformers can block the signals, though in some places they might be bypassed for BPL, broadband over power line, or control signals in the smart grid. Even if nothing is bypassed, the neutral line can get your signal out past the transformers. It all depends on how your grid is set up and sectionalized, and what signals might leak to other sections.
I'd suggest a test to see what you might be able to do, though it could be hard to get the equipment these days, where you'd want to have at least a few watts in the transmitter and need a power line tuner (coupler) to do it right.
Boomer
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Post by Deleted on Dec 28, 2017 16:52:55 GMT
Everything About Carrier Current
The ALPB resources found on the website include large amounts of carrier current documents, especially from the LPB days when Low Power Broadcast Inc. sold couplers and transmitters, now coveted items still found on Ebay at times.
Three episodes of the Low Power Houre are devoted to carrier current, with engineer RFB (not related to the RFB that posts at Hobby Broadcaster).
The Part 15 Page at the KDX website also has links to many carrier current papers.
In the present day Radio Systems makes a carrier current transmitter and coupler.
Tha Dood, a part 15 operator in W. Virginia, has been using a fairly priced Greek mad AM transmitter for carrier current, and evidently it is a good choice.
The 2 main methods of coupling to the AC power system are 1.) coupling to the 3-wires of 220VAC; 2.) the Neutral Injection Method, the specifics of both types linked at the ALPB website.
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Post by jimhenry2000 on Dec 29, 2017 3:22:40 GMT
Thanks Boomer and Carl. Everything About Carrier CurrentThe ALPB resources found on the website include large amounts of carrier current documents, especially from the LPB days when Low Power Broadcast Inc. sold couplers and transmitters, now coveted items still found on Ebay at times. Three episodes of the Low Power Houre are devoted to carrier current, with engineer RFB (not related to the RFB that posts at Hobby Broadcaster). The Part 15 Page at the KDX website also has links to many carrier current papers. In the present day Radio Systems makes a carrier current transmitter and coupler. Tha Dood, a part 15 operator in W. Virginia, has been using a fairly priced Greek mad AM transmitter for carrier current, and evidently it is a good choice. The 2 main methods of coupling to the AC power system are 1.) coupling to the 3-wires of 220VAC; 2.) the Neutral Injection Method, the specifics of both types linked at the ALPB website. |
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Post by jimhenry2000 on Dec 29, 2017 5:06:01 GMT
Carl, Can you post some specific links? I'm looking through the site (theALPB.com) and so far not finding any documents. Thanks. Jim Everything About Carrier CurrentThe ALPB resources found on the website include large amounts of carrier current documents, especially from the LPB days when Low Power Broadcast Inc. sold couplers and transmitters, now coveted items still found on Ebay at times. Three episodes of the Low Power Houre are devoted to carrier current, with engineer RFB (not related to the RFB that posts at Hobby Broadcaster). The Part 15 Page at the KDX website also has links to many carrier current papers. In the present day Radio Systems makes a carrier current transmitter and coupler. Tha Dood, a part 15 operator in W. Virginia, has been using a fairly priced Greek mad AM transmitter for carrier current, and evidently it is a good choice. The 2 main methods of coupling to the AC power system are 1.) coupling to the 3-wires of 220VAC; 2.) the Neutral Injection Method, the specifics of both types linked at the ALPB website. |
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Post by Boomer on Dec 29, 2017 7:50:01 GMT
Howdy Jim Henry 2K, you might try here, I think this is the page Carl is referring to. thealpb.com/equip-info.htmNear the bottom of the list is the LPB Application Notes ZIP file. Also see 'Carrier Current Broadcasting Parts 1 & 2' articles by Tha Dood for a take on CC for the hobbyist, home to neighborhood. That was one of the articles I read early on. I'd consider Tha Dood to be an expert on the hobbyist side of Carrier Current DIY with years of experience. Come to think of it, TheALPB should have the Popular Communications article on CC but I don't see it, that's truly an early source that was riveting for me when I first read it. Not sure if I sent that to Carl or not yet. |
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Post by Deleted on Dec 29, 2017 10:12:51 GMT
Carrier Current LinksOn the ALPB Page linked by Boomer these are some CC links: Low Power Broadcasting - J.R.CunninghamCarrier Current - Tha DoodALSO while on the ALPB Page linked by Boomer scroll near the end of the list and grab the LPB Application Notes Zip File. This ZIP file contains the sheet on wiring for Neutral Injection.
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Post by Boomer on Dec 29, 2017 20:24:40 GMT
Yes, those are the links I was thinking of Carl! Just thinking.. The Weather might be a reason we're pondering Carrier-Current more right now, most of the work is done indoors..  Boomer |
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Post by Admin on Dec 30, 2017 3:11:21 GMT
Traditional vrs Neutral Injection
Jim, if you couple the RF the traditional way, between the AC hot and neutral, the RF will be blocked by the distribution transformer. It acts like an RF choke.
As such the signal will only propagate to houses connected to the same 120/240 lines. On my street there are about 10 homes fed from one transformer. The signal would reach those homes.
Neutral injection puts the RF between the distribution neutral and an isolated ground. The distribution neutral connects to the transformer but the RF does not have to pass through the transformer. Rather, it follows the neutral.
Most distribution systems have a common neutral. The neutral may interconnect around the entire system. This gives a very large path around town for the RF. Of course the signal will be attenuated as it passes further away.
Carrier current is affected by many variables on the line as devices are turned on and off. It requires some tinkering and monitoring, adjusting the tuning occasionally.
When I get done tinkering I'll provide some intel on the operation.
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Post by jimhenry2000 on Dec 30, 2017 6:27:27 GMT
Thanks found it. Howdy Jim Henry 2K, you might try here, I think this is the page Carl is referring to. thealpb.com/equip-info.htmNear the bottom of the list is the LPB Application Notes ZIP file. Also see 'Carrier Current Broadcasting Parts 1 & 2' articles by Tha Dood for a take on CC for the hobbyist, home to neighborhood. That was one of the articles I read early on. I'd consider Tha Dood to be an expert on the hobbyist side of Carrier Current DIY with years of experience. Come to think of it, TheALPB should have the Popular Communications article on CC but I don't see it, that's truly an early source that was riveting for me when I first read it. Not sure if I sent that to Carl or not yet. |
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