Base antenna for both Scanner and SDR

[lb2910]

Hello all. Figured I'd re-route this question to the proper forum. I recently bought a Uniden SDS100 and LOVE it. I also dabble in the SDR realm of scanning which I find fun as well. What I am looking for are some killer recommendations for a good "all around" wide/multi band base antenna. I hope the below info and my attached pictures help with describing my unique environment...

As the attached pics show, my house is rectangular with the back of the house facing north and the front facing south. The south roof top is covered in solar panels. Roughly 80% of the radio traffic I want to hear is north of my house or east of my house. Just north of me is Washington DC. East of me is Regan National Airport (KDCA) and also most of the towers for my local public safety agencies. The picture showing the front of my house has a red circle showing the window of my office which is where my scanner and SDR set up resides. Taking all that into account, I am looking to install a base antenna that can pull double duty. I would like it to be a solid base antenna for my SDS100 but also, one that I can use to pull in some radio traffic with my SDR set up. I do not live in an HOA neighborhood so I can mount the antenna wherever I want. That said, I like discreet, clean and unobtrusive as much as possible. The locations I'm thinking about mounting the antenna is either just outside my office window, on the chimney or inside my attic. Note that if I mount on the chimney, I'm looking at about 40-50 feet or so of coax run. I know this can cause a lot of signal loss so thought I'd mention that. If I mount inside my attic or just outside my office window, the coax run would be fairly minimal.

I tend to listen to all bands with the majority being 800MHz trunked and the aviation band. There are some agencies I listen to on VHF high. That said, I'd like a wide band antenna so I can get reliable performance on any band. My budget would be $200-$300 or so. If go a bit over on an excellent performing set up, I'm ok with that. I understand that height is the key which is why the chimney is an option but I'm concerned over the length of the coax run. There is a large wooden stick holding up my weather anemometer on the chimney. I can probably mount an antenna on it with some creative mounting options.

I've looked at Diamond/Tram/Comet Discone antennas, Procomm Spider antennas, etc. I've read some bad reviews on the Spider but I know sometimes they can be deceiving. I currently have a Remtronix on the SDS100 and use the pre-packaged antennas with my SDR set up. As always, this forum is a gold mine of experience, help and knowledge. Thanks to all that help me out with this... stay safe...

 

[Omega-TI]

You are pretty much in the same realm as I am. I recently purchased an SDS100 (also love it) and I also dabble with a RTL-SDR. This spring or summer I plan to remove the dish on an old HughesNet setup I once used and attach an antenna to that. I'll remove the old cabling and use the same exact holes to route the coax through. I'll have to split it off once it comes into the den though because my computer and "listening post" are on opposite sides of the den.

In my case most of the stuff I listen to is VHF with very little UHF. I'll probably mount it about 10 feet above the house as I'm at an elevation of 1,200 feet on a high plain and the main thing is to get the antenna further away from the RFI in the den. I'm still going to have to research the coax though, I would really like to avoid huge think honking cable like Belden 9913.

 

[scanmanmi]

I went from a crummy 1/4 wave at 10' with crummy coax to a super gain antenna at 35' with LMR400 coax and it's a world of difference. A few points though. I think a good antenna with great coax at 10' would actually be pretty comparable. Now I have no access to the antenna because it's on a tower. I lost a lot of signal on my horizontal run. I don't know why anyone would ever consider buying a discone.

 

[trap5858]

The Diamond Discone is hard to beat for a wide coverage antenna. It does not offer an gain (unity gain) but does a pretty good job across and in some instances beyond the advertised frequency range. Of course the best antenna is one that is specifically tuned to resonate on the frequency you desire to listen to. It all depends on your needs and ability to tolerate some imperfection in the quality of the signal received. The real key to the success of the antenna is elevation over obstructions and distance from the transmitting source.

 

[lb2910]

The Diamond Discone is hard to beat for a wide coverage antenna. It does not offer an gain (unity gain) but does a pretty good job across and in some instances beyond the advertised frequency range. Of course the best antenna is one that is specifically tuned to resonate on the frequency you desire to listen to. It all depends on your needs and ability to tolerate some imperfection in the quality of the signal received. The real key to the success of the antenna is elevation over obstructions and distance from the transmitting source.

I went into this "project" knowing I'd have to compromise on some things since I know having an antenna cut to specific freqs is always best. Since I want a wide-band antenna to cover so much I know the performance won't be as good but I'm ok with that. Based on some of the responses, I'm leaning toward mounting the antenna just outside my office window since the coax run will be fairly short. The issue with mounting there is I may not get the height I want. So the $64 question is what gives better performance, shorter coax runs or height? I will ultimately have to pick one.

 

[Ubbe]

Go up to your chimney and listen with your scanner to check what can and cannot be heard. Compare that to what you would like to hear.
You have your house and chimney very low so you could just as well have a mast pole outside your window, fastened with two brackets to the wall long enough to clear the gutters and above the roof line and use a discone.

Ideally you would want to clear the tree tops but that looks to be too problematic due to the height needed.

If you later notice any problems to receive systems in the 800Mhz band you could always add a second dedicated 800MHz gain antenna to the mast pole and use a diplexer to combine the two antennas.

/Ubbe

 

[lb2910]

I thought about running two antennas as well. A discone and one cut specifically for 800MHz so that may be an option. For the mounting, is it better to mount the antenna with a metal pole vs a wooden one? Does the metal help with grounding and better reception at all?

 

[popnokick]

So many things to consider... so here goes -
- Even if you went from either the chimney or the other end of the house using a gable / eave mount, it doesn't look like more than 75 feet of coax would be involved. That's not too long a run if you use good coax.
- So what would be good coax for your receive-only installation? Least cost, highest performance for the buck, and easiest to install will be RG-6 CATV coaxial cable available at any hardware store, with minimal hassle to attach connectors and cable clips. Some will tell you to use "quad shield" RG-6... wouldn't hurt and it also is available in the store. If you're skeptical and want to spend more time / money go with LMR-400 or similar... and be prepared for more time and trouble than you thought to attach the connectors. DO NOT use RG-58, RG8, RG8X, or similar high-loss cables. They will lose a lot of your 800 mHz and other UHF signals.
The RG6 cable will also permit you to use F-connectors and a simple CATV grounding block on the coax. You'll need a simple pigtail adapter to go from the F-male on the end of the coax to your SDS100 (F-female to SMA male).
- The solar panel array on your roof poses two potential problems: 1) They are notorious for emitting RFI-EMI, and 2) they are really going to attenuate signals to the south if you mount an antenna in the attic. So don't do that.
- Use metal for the antenna mast. Wood will rot and plastic will bend and even break.
- If you don't want to use the chimney, go to the other end of the house and use an eave / gable mount like this one -
Winegard Adjustable Gable End Mount for Antenna Masts (SW-0012)
(NOT the antenna in the pic which is there to illustrate how an eave mount works... just the mount. No holes in your roof, no relying on strapping to the chimney, and easily clears the roofline giving your antenna a 360 view all around the house.) You'll need some TV antenna mast... I wouldn't go more than 20 feet (two 10 ft sections if you can find 'em).

 

[lb2910]

So many things to consider... so here goes -
- Even if you went from either the chimney or the other end of the house using a gable / eave mount, it doesn't look like more than 75 feet of coax would be involved. That's not too long a run if you use good coax.
- So what would be good coax for your receive-only installation? Least cost, highest performance for the buck, and easiest to install will be RG-6 CATV coaxial cable available at any hardware store, with minimal hassle to attach connectors and cable clips. Some will tell you to use "quad shield" RG-6... wouldn't hurt and it also is available in the store. If you're skeptical and want to spend more time / money go with LMR-400 or similar... and be prepared for more time and trouble than you thought to attach the connectors. DO NOT use RG-58, RG8, RG8X, or similar high-loss cables. They will lose a lot of your 800 mHz and other UHF signals.
The RG6 cable will also permit you to use F-connectors and a simple CATV grounding block on the coax. You'll need a simple pigtail adapter to go from the F-male on the end of the coax to your SDS100 (F-female to SMA male).
- The solar panel array on your roof poses two potential problems: 1) They are notorious for emitting RFI-EMI, and 2) they are really going to attenuate signals to the south if you mount an antenna in the attic. So don't do that.
- Use metal for the antenna mast. Wood will rot and plastic will bend and even break.
- If you don't want to use the chimney, go to the other end of the house and use an eave / gable mount like this one -
Winegard Adjustable Gable End Mount for Antenna Masts (SW-0012)
(NOT the antenna in the pic which is there to illustrate how an eave mount works... just the mount. No holes in your roof, no relying on strapping to the chimney, and easily clears the roofline giving your antenna a 360 view all around the house.) You'll need some TV antenna mast... I wouldn't go more than 20 feet (two 10 ft sections if you can find 'em).

BOOYAH.. that mount is MONEY... for the coax, I priced both out and the LMR-400 is definitely more expensive for a 100ft roll. Based on the pain in the a$$ you stated with doing the connectors with the LMR, is the juice worth the squeeze? Is the end result of using the LMR worth going through the hassle of the connectors and added cost over the RG-6 considering my run will be well under 75 feet no matter where I mount?

And lastly, the antenna for this set-up.... Discone??

 

[popnokick]

Higher coaxial cable loss will occur at your highest frequencies of interest, which you wrote are 800 mHz. So for 75 feet of coaxial cable and comparing RG6 to LMR400, the RG6 will be about 4.2 dB and the LMR400 about 2.7dB loss. Barely noticeable to your ear... you can decide if it's worth the additional $$$ and effort to install the LMR. For the antenna, try this which presents low wind loading, good performance across a wide frequency range, some gain vs the zero gain of a discone, and meets your "cleaner and unobtrusive" desire compared to a discone -
https://dpdproductions.com/collecti...-antennas/products/omnix-scanner-base-antenna

 

[lb2910]

Thanks @popnokick !!! That antenna is right up my alley... I like the look and after reading some threads on here regarding the performance, I think I'll go with that antenna. For the coax, I'll go with the RG6 since the loss is barely noticeable. Many thanks!!!

 

[popnokick]

This may seem odd, but I'm relieved that you took the initiative to read the reviews / comments regarding the DPD Omni-X here on RR. That's a very good way to find out who is having what experiences with the Omni-X (or any antenna)... and I didn't have to point you to those posts!

 

[lb2910]

This may seem odd, but I'm relieved that you took the initiative to read the reviews / comments regarding the DPD Omni-X here on RR. That's a very good way to find out who is having what experiences with the Omni-X (or any antenna)... and I didn't have to point you to those posts!

Thanks for saying that @popnokick.. I feel like you good folks are giving your time helping us radio amateurs so if you offer up a recommendation, the first thing I do is search the product on RR to see what everyone else's experience is with the item. Thats why I steered away from the Procomm Spider antenna. Too many negative experiences for my liking. The Omni-X fits my "cleaner" look and seems to perform well. SOLD!!! HAHA..

So for connections and cable... my intention is to order everything at once and hopefully do the install in a few hours. I noticed the Omni-X has 16 inches of RG8X. I will be using RG6 per your recommendation. Any issues with joining the two different cable types?

For the connections, I see that Omni-X comes with a female N connection. So obviously I'll get the male N connection for that end. For the scanner end, I have the Uniden SDS100 with SMA and the BNC adapter. Any preference of connection on the scanner end?

Depending on how easy this coax run will be, I might even do a wall box installation (like a typical outlet or TV cable) for a clean look in my office. Then just have a short length of coax that connects from the wall box to my scanner on the desk. Again.. IF the run goes easy and timely.

Thanks again for all the help!!!

 

[popnokick]

The short RG8X pigtail on the Omni-X won't be an impedance issue even though it is 50 ohms. Finding an N-Male connector that fits on RG6 won't be easy... use an N-male to F-female pigtail. Wrap everything with self-fusing waterproofing tape such as Nashua Stretch-n-Seal or equivalent (also available in big box hardware stores). On the scanner end use an F-female to SMA pigtail, eliminating the SMA to BNC adapter. And of course if you do go the utility box / wall cover route you can put an F-female on the wall box and use whatever you want to go from the wall to the scanner... but stay with the RG6 and an adapter or pigtail when you get to the scanner. The wall box will be neater if you decide to add a multi-coupler or additional radio.