Just looking for some input on my current installation. I have just installed a Diamond D130J antenna and have a run of approximately 100' of RG6 Quad shield cable to my scanner. I want to install a Stridsberg MCA204M multicoupler at my scanner location to add another scanner(s) in the same location. Out of one of the remaining ports, I want to run a cable another 40' to a single scanner in another room. Does this sound reasonable, or should I be looking to install a pre-amp near the antenna? Any assistance is greatly appreciated.
Antenna/multicoupler advice needed
- Thread starter davidg71
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First, you should be looking to replace that 100’ of RG6 with something with a lower loss. For that length I’d go with at least LMR400.
Might have a bit of signal loss, but nonetheless it will work. I have the same antenna and just recently the MCA204MIL, only 50-60 ft run of RG8U to the entry point in the basement room, then RG6 all the ways up to the 2nd floor upstairs. I'm fine with the signals that I get.
I will definitely look into replacing the RG6. Thanks.
Sounds good, thank you.
Ubbe
Member
That RG6 will attenuate 6dB at 800Mhz and LMR400 4dB. It's just a 2dB difference and probably not worth the investment and the trouble to install. A Stridsberg will have some gain in the 3dB region so that will compensate for that 40' run out of it.
If you have channels and systems that are weak in signal strength that you would like to be improved, then the way to go are an antenna amplifier and two passive splitters. One 1-2 splitter from the coax where one output goes to that 40' run and the other to another splitter with enough outputs to support your current and future number of receivers. Then you don't have to worry over what coax to use and you have to instead use attenuators before that multi splitter and at the other end of the 40' run coax. Variable attenuators are the best as you then can adjust to the exact signal level where reception are the best without overloading the receiver.
If you have issues with low signal levels in the 700-900MHz band then most discone antennas are usually 10dB worse in reception compared to a standard vertical antenna. Most discones works best between 100-500MHz and outside of that range they degrade in performance. If all you receive have good signal strengths then you might not even need any amplification at all and just use passive splitters. A 1-2 splitter attenuates some 4dB and a 1-4 maybe 7dB. If you have a signal meter, like the one in SDS scanners or in a spectrum program like SDR# then you can see if you can handle a 4+7dB loss in level additional to what you already have in your RG6 coax loss of 6dB+3dB.
/Ubbe
If you have channels and systems that are weak in signal strength that you would like to be improved, then the way to go are an antenna amplifier and two passive splitters. One 1-2 splitter from the coax where one output goes to that 40' run and the other to another splitter with enough outputs to support your current and future number of receivers. Then you don't have to worry over what coax to use and you have to instead use attenuators before that multi splitter and at the other end of the 40' run coax. Variable attenuators are the best as you then can adjust to the exact signal level where reception are the best without overloading the receiver.
If you have issues with low signal levels in the 700-900MHz band then most discone antennas are usually 10dB worse in reception compared to a standard vertical antenna. Most discones works best between 100-500MHz and outside of that range they degrade in performance. If all you receive have good signal strengths then you might not even need any amplification at all and just use passive splitters. A 1-2 splitter attenuates some 4dB and a 1-4 maybe 7dB. If you have a signal meter, like the one in SDS scanners or in a spectrum program like SDR# then you can see if you can handle a 4+7dB loss in level additional to what you already have in your RG6 coax loss of 6dB+3dB.
/Ubbe
If what you have meets your need, then that's great.
But it's a lot more than a "bit" of signal loss. At 150 MHz you'll be losing about 65% of any received signal and it gets worse as you go up in frequency. At 450 MHz the loss is about 77%, and if you are trying to listen to an 800 MHz system, close to 87%. Depending on what you are trying to listen to and how strong the signals are, that might not be an issue. But if you are interested in distant weaker signals, it will be.
*You have a high quality Diamond Discone antenna (I have several). Possibly a different antenna with gain (I did)? What are your listening targets?
*You're looking to start tapping into a Stridesberg multicoupler (I plan on one as well) ...again high quality and pricey...SO you want a setup/coax run to get the most bang for the buck out of that investment.
*You want to start adding another scanner(s) and longer runs (network) of coax in the house...in for a penny-in for a pound they say with a more complex setup.
*With what you are investing and hopeful plans for goodness sake don't go cheap on the main line coax...at this point "good enough" is shooting yourself in the foot. If you're gonna go quality, go all the way and not introduce a weak link into your setup. Go for the LMR-400.
*You're looking to start tapping into a Stridesberg multicoupler (I plan on one as well) ...again high quality and pricey...SO you want a setup/coax run to get the most bang for the buck out of that investment.
*You want to start adding another scanner(s) and longer runs (network) of coax in the house...in for a penny-in for a pound they say with a more complex setup.
*With what you are investing and hopeful plans for goodness sake don't go cheap on the main line coax...at this point "good enough" is shooting yourself in the foot. If you're gonna go quality, go all the way and not introduce a weak link into your setup. Go for the LMR-400.
Hi davidg71,
Your proposed setup sounds very close to mine. I wonder what the highest frequency you'll be monitoring is (860MHz?) as that dictates how good of cable you should have from antenna to amplifier (I'm using Air-802 an LMR-400 alternative). Next are you in a rural or urban environment? I am near paging transmitters, cell towers, and AM/FM broadcast towers. Near doesn't necessarily mean distance, but how strong the signals are at your antenna. I added filters to reduce those signals before my amplifier/multi-coupler.
Some outputs of my multi-coupler travel about 20 feet to get to the receivers. One goes about 50 feet to literally get to the other side of the house. I am using high quality (low-loss) RG-6 for these w/o issues. Certainly there is signal loss to the far destination, but well within the margin of what I am monitoring. Could I have used that LMR type cable for that long run? Yes? But the value to effort (ROI) was not there. YMMV.
Your proposed setup sounds very close to mine. I wonder what the highest frequency you'll be monitoring is (860MHz?) as that dictates how good of cable you should have from antenna to amplifier (I'm using Air-802 an LMR-400 alternative). Next are you in a rural or urban environment? I am near paging transmitters, cell towers, and AM/FM broadcast towers. Near doesn't necessarily mean distance, but how strong the signals are at your antenna. I added filters to reduce those signals before my amplifier/multi-coupler.
Some outputs of my multi-coupler travel about 20 feet to get to the receivers. One goes about 50 feet to literally get to the other side of the house. I am using high quality (low-loss) RG-6 for these w/o issues. Certainly there is signal loss to the far destination, but well within the margin of what I am monitoring. Could I have used that LMR type cable for that long run? Yes? But the value to effort (ROI) was not there. YMMV.
I appreciate the replies and all the info. Besides the Stridsberg multicoupler, is there an Electroline model That would satisfy my needs and not break the budget. I am very satisfied with the performance of my scanner with the current antenna I have and the use of the RG6. Not saying I'm not going to try and improve my set up but now I am stuck trying to figure out what multicoupler will work best. I have read about issues with orders from Stridsberg, so I am looking for an alternate route. Any assistance is greatly appreciated.
Roll your own using a low noise high level preamp with 10-15dB of gain feeding a good passive 4 or 8-way divider. You can usually find the parts used on eBay for less than the cost of a Stridsberg and the performance will be much better.
p1879
Member
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- Mar 15, 2004
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Using the Cross Country Wireless 5 port multicoupler here with a Channelmaster 5094 and 25' RG-6, for well below 500 Mhz. 4 Ft jumpers to radios. It seems acceptable, but not too exciting reception-wise to me. I think people have commented that outputs on the CCW multicoupler have some variation....
Perhaps will replace the balun one day with the new Channel master 25$ balun.
Perhaps will replace the balun one day with the new Channel master 25$ balun.
Ubbe
Member
Their UG series (Unity Gain) have 0dB gain from their outputs and specification equals Stridsberg, or even better. See to that you get a power supply with it. Or check that you can get a cable with a F connector at one end and suitable leads at the other to connect to a power supply, or make your own power cable. Those UG models are something like $50 brand new but as second hand on Ebay but no guarantee that they'll work so I would probably buy from a company to get a year or longer warranty. There are new $30 UG types complete with power supply from excess-supply.com but they seem to give no warranty at all.
/Ubbe
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