One antenna to replace them all

I currently have three antennas on my roof. One is for ADS-B, one is for marine AIS, and the third is for general scanning (VHF high and UHF low). I would like to replace this with one single antenna and split it three ways in my office with an amplified splitter. I am looking at the Tram 1410. Can anyone give me any big drawbacks of this setup? My current ADS-B and AIS antennas are professional grade although I have high signal loss through 30 feet of RG-174 and I assume I can easily halve that through better cabling to offset any loss on a wideband antenna. Is this line of thinking correct? This setup will be for receiving only, no transmitting. Thanks!

You can use the current coax and place a good amplifier at the mast foot and power it thru the coax.
There will be plenty of signal left for driving a splitter to several receivers.

RG174 attenuate some 10dB for your ADS receiver so it is probably an improvement even using a discone antenna.

AIS will probably also improve as 160MHz with RG174 cut the signal in half and using the discone with an amplifier will at least match a 5/8 GP antenna for AIS.

There is several threads about amplifiers you should read before buying the amp.

/Ubbe

Discones work OK. Just OK.
As you know, their design makes them very broad band, but gives you zero gain.

If your primary listening interest in VHF/UHF, then you'll get better performance with a dual band amateur radio antenna. It'll give you a couple dB of gain on VHF and UHF.
I've got two discone antennas that I use. One is a Diamond. It's at my house, got it for free, and it's connected to a Moto. VHF CDM-750 for amateur and work use. It's done OK over the years, not an outstanding performer, but "good enough".
I've got a Telwave ANT280 at work, works as well as the Diamond, but a lot more durable.

Personally, if i was in your shoes, I'd get one of these: https://www.theantennafarm.com/catalog/diamond-x50a-4869.html?zenid=d50f42ba208c2595a0b39fd2ae2fc9f4
A bit more money, but it has some real gain where you want it.

Feed that with some good coaxial cable, LMR-400 or better, and you'll have a good system for your scanner and AIS receiver. Bonus is that if you decide to get your amateur radio license down the road, you won't have to invest in another antenna.

As for ADS-B, keep it on it's own dedicated antenna. Since it's running just above 1GHz, a dual band VHF/UHF antenna probably isn't going to work well. Ditch the RG-174 and feed it with some of the LMR-400 on it's own feed.

Works Well

You could try an MP Antenna Classic Base Antenna 08-ANT-0863 (25 MHz – 1300 MHz) with Stridsberg MCA204M/N multicoupler and LMR-400 cable. I'd get rid of that RG-174 for sure even if you're just receiving.


RG-174
Frequency - 25 MHz - 1.3GHz
Loss - 1.3 dB - 9.5 dB

LMR-400
.2 dB - 1.6 dB

Below are links.

Classic VHF UHF Base Station Antenna 25MHz
Receiver Multicouplers, Passive and Active, HF to VHF/UHF

If you're not in the mood for making cable.
https://usacoax.com/

Thanks for the replies! I'll keep the LMR-400 in mind but I may cheap out and go RG-6Q since I have no plans on transmitting on this antenna so impedance mismatch isn't really an issue. It's about halfway in between LMR-400 and the current RG-174 if I remember correctly.I know a wide-band antenna isn't ideal for ADS-B, but I was hoping the upgrade in cable or adding an amp would offset any dB loss. Everything I scan is between 100-500MHz with the exception of the ADS-B receiver.

Just be careful with where you put the amplifier in the chain. They are not perfectly flat across the spectrum, and I'd want to look very closely at how one that would work well on VHF and UHF would do with 1090MHz for ADS-B. Noise can become an issue, especially if you have any cell sites nearby.
When I put up the ADS-B receiver I have at work, it worked well at one of my high sites. Then one day it stopped working. That matched the day that Verizon turned up their 700MHz LTE gear at the same site.

Not sure a single Discone will do very well for ADS-B, the patterns for scanner types start to get squirrely above about 500MHz. A DIscone will do fine for your Marine and general VHF-UHF scanning.

I would upgrade the coax as others have mentioned then consider the Tram Discone for marine and VHF/UHF scanning then a separate ADS-B antenna with a 1090MHz filter and preamp. Then a pair of diplexers (one at the antenna and one indoors) like the Diamond MX-37 that will pass 1.6 to 470Mhz on one side and 900-1300MHz on the other side which will allow everything to pass down one coax. The Comet CS-413B diplexer is similar.

You can then feed a hot signal to your ADS-B receiver and use an amplified multi coupler to feed your AIS receiver and scanner.

I have antennas that would do a good job for you but are hard to find like one made for military IED jammers. Half the antenna covers about 100 to 600MHz and the other covers about 700MHz to about 6GHz in a long skinny tube. That would make a single and nice low profile antenna for everything.
prcguy

If the discone vs dedicated antenna isn't more than 6-7dB of loss, that will be fine as the cable replacement will make up for it. My current setup with the RG-174 works great as it is. I guess I'll setup both antennas and test to see what the result is. Part of the fun of the hobby I suppose!

I had to blink a few times, rub my eyes, and read the OP again... RG-174 for a 30 foot outdoor run? At 700 mHz that's more than 7dB of loss; at 400 mHz it's more than 5dB. And the responses were mild suggestions to change the coax, or said nothing about the coax. Maybe I've gotten bad advice over the years, but I've always treated RG-174 as a "small device" convenience for runs 3 feet and under, or something short and flexible to use on the bench.
No question that the LMR-400 would be better (and $$) but since you are only receiving RG-6 is a good choice for performance vs. cost. At 700 mHz it will be about 1.5 dB loss for your 30 feet, and only about 1.1 dB at 400 mHz. Waay better than RG-174.

popnokick said:

I had to blink a few times, rub my eyes, and read the OP again... RG-174 for a 30 foot outdoor run? At 700 mHz that's more than 7dB of loss; at 400 mHz it's more than 5dB. And the responses were mild suggestions to change the coax, or said nothing about the coax. Maybe I've gotten bad advice over the years, but I've always treated RG-174 as a "small device" convenience for runs 3 feet and under, or something short and flexible to use on the bench.
No question that the LMR-400 would be better (and $$) but since you are only receiving RG-6 is a good choice for performance vs. cost. At 700 mHz it will be about 1.5 dB loss for your 30 feet, and only about 1.1 dB at 400 mHz. Waay better than RG-174.

Click to expand...

I agree the RG-174 is crap, but it was what came with the receiver package. Hence the replacement

May Have Not Read it All

popnokick said:

I had to blink a few times, rub my eyes, and read the OP again... RG-174 for a 30 foot outdoor run? At 700 mHz that's more than 7dB of loss; at 400 mHz it's more than 5dB. And the responses were mild suggestions to change the coax, or said nothing about the coax. Maybe I've gotten bad advice over the years, but I've always treated RG-174 as a "small device" convenience for runs 3 feet and under, or something short and flexible to use on the bench.
No question that the LMR-400 would be better (and $$) but since you are only receiving RG-6 is a good choice for performance vs. cost. At 700 mHz it will be about 1.5 dB loss for your 30 feet, and only about 1.1 dB at 400 mHz. Waay better than RG-174.

Click to expand...

You probably missed this from post 4:

...I'd get rid of that RG-174 for sure even if you're just receiving.


RG-174
Frequency - 25 MHz - 1.3GHz
Loss - 1.3 dB - 9.5 dB

LMR-400
.2 dB - 1.6 dB

Nice of the folks who made your ADS-B / AIS receiver package to include coax that provides a 9.5 dB LOSS (!!!) at 1.3gHz.... which is very near the 1.09 gHz (1090 mHz) ADS-B freq. What were they thinking when they designed that?

popnokick said:

Nice of the folks who made your ADS-B / AIS receiver package to include coax that provides a 9.5 dB LOSS (!!!) at 1.3gHz.... which is very near the 1.09 gHz (1090 mHz) ADS-B freq. What were they thinking when they designed that?

Click to expand...

It's the free receiver package from FlightRadar24 to upload data to their network. Everything is top notch but I was puzzled at the RG-174. I was hoping switching to RG-6Q and switching to the discone would keep things about even. I guess I'll find out. If performance is worse I'll run another line and reinstall the dedicated ADS-B antenna. My main goal is to reduce clutter on my roof.

jsncrso said:

It's the free receiver package from FlightRadar24 to upload data to their network. Everything is top notch but I was puzzled at the RG-174. I was hoping switching to RG-6Q and switching to the discone would keep things about even. I guess I'll find out. If performance is worse I'll run another line and reinstall the dedicated ADS-B antenna. My main goal is to reduce clutter on my roof.

Click to expand...

I have one of the "free" Flight Radar24 units, and it came with LMR-240. I suspect they use the RG-174 since it's easier for people to route.
When I installed mine, I used some LMR-400. I regularly get 300NM range from mine. Most of that is because of altitude and location (900 feet above the Pacific coast), but some of it likely has to do with higher grade coax.
Same with the AIS receiver I have. I've hit 600 mile range from a 900 foot high site looking out over the Pacific. LMR-600 feeding that guy.

Improving your coax will probably help, but limitations are also from your antenna height. ADS is line of sight. AIS can get some interesting skip, especially when you consider they are only putting out 25 watts at best.

How long is your ADS-B antenna? If its a couple feet long it can have some reasonable gain and greatly outperform a Discone. If its real small it may be low gain and only a little better than a Discone.
prcguy

jsncrso said:

It's the free receiver package from FlightRadar24 to upload data to their network. Everything is top notch but I was puzzled at the RG-174. I was hoping switching to RG-6Q and switching to the discone would keep things about even. I guess I'll find out. If performance is worse I'll run another line and reinstall the dedicated ADS-B antenna. My main goal is to reduce clutter on my roof.

Click to expand...

Two items -

Regular RG6 rather than quad shield should be sufficient unless you have extreme amounts of noise be induced to the feedline along its path (like running over the top of florescent lights). The loss is nominal compared to dual or tri shield RG6 but quad shield requires special connectors to terminate.

Discone antennas for ADS-B *suck*. The broadband qualities of the antenna are negated by the lack of gain and overwhelming majority of the radiation pattern near or below the horizon. Stick to the dedicated ADS-B antenna - it is by far the best solution. Upgrading from RG174 to RG6 will improve things quite a bit as long as you don't add a bunch of adapters to the signal chain.

When testing antennas for ADS-B reception at my house about 30 miles from the major airport, I had best luck with a single VHF folded dipole at roof level, only bested by a dedicated ADS-B antenna.

I agree there is no need to use quad shield RG-6, even for regular VHF/UHF scanner use. Regular RG-6 CATV or satellite types already have a 100% foil shield plus a braid. The loss spec is identical between regular and quad shield from the same mfr.

Quad shield is useful when you have a bunch of tightly bundled cables carrying both high level (0dBrm range) transmit signals and some and low level receive (-50dBm or lower) in the 2GHz range. Thats where you will see an improvement from the additional shielding, otherwise its a waste of time and money.
prcguy

IdaScan said:

Two items -

Regular RG6 rather than quad shield should be sufficient unless you have extreme amounts of noise be induced to the feedline along its path (like running over the top of florescent lights). The loss is nominal compared to dual or tri shield RG6 but quad shield requires special connectors to terminate.

Discone antennas for ADS-B *suck*. The broadband qualities of the antenna are negated by the lack of gain and overwhelming majority of the radiation pattern near or below the horizon. Stick to the dedicated ADS-B antenna - it is by far the best solution. Upgrading from RG174 to RG6 will improve things quite a bit as long as you don't add a bunch of adapters to the signal chain.

When testing antennas for ADS-B reception at my house about 30 miles from the major airport, I had best luck with a single VHF folded dipole at roof level, only bested by a dedicated ADS-B antenna.

Click to expand...

If you read the different ADS forums you'll notice that the best antennas they use are the ones that they stack 6 or 9 elements on top of each other. It will give gain and the loob will be super flat only pointing at the horizon. So no need to have any air frequency antennas pointing up in the air in belief it will increase reception.

/Ubbe