Antenna advice requested

[gearhead1961]

I have been an on-and-off scanner /SWL enthusiast for decades. Since I am recently retired and have the time to get serious about things, I finally got my Technician ticket (and picked up a GMRS license for good measure). I have enough radios sitting in the closet to outfit my new shack so the next real challenge is all about antennas. I have been on a buying spree lately and now have a Comet discone for the scanner(s), a Tram 2m/70cm base antenna, a Pixel vertical for MW/FM broadcast and an MLA30+ loop for SWL. All that remains on the shopping list is an HF antenna for my IC-718.

I live in Las Vegas in a two story stucco house with a concrete tile roof. The HOA is fairly easy to get along with but I am certain that turning my house into an antenna farm would eventually lead to trouble (and cause a big headache with the Mrs. as well).

Placing at least some of these antennas in the attic would streamline the process but I am concerned about a) the impact of the concrete tile roof and b) crosstalk between the antennas in a smallish attic space.

I am hoping that someone with far more radio experience than I has some thoughts and observations on all of this. Can I stuff some of them into the attic without a significant sacrifice in performance? If so, which ones would be the likely candidates?

Thanks in advance for your advice!

 

[mmckenna]

Placing at least some of these antennas in the attic would streamline the process but I am concerned about a) the impact of the concrete tile roof and b) crosstalk between the antennas in a smallish attic space.

I am hoping that someone with far more radio experience than I has some thoughts and observations on all of this. Can I stuff some of them into the attic without a significant sacrifice in performance? If so, which ones would be the likely candidates?

Thanks in advance for your advice!

Putting the antennas in the attic will work. Question is, how well?
The issue you want to watch out for is any metal between the antennas and the outside. If it's a plywood sheath with concrete tiles over it, that should be fine. If there is any metal, foil backed insulation, or a lot of HVAC ducts/wiring, then you'll have challenges.

"crosstalk" between the antennas can be addressed by two things:
Spread the antennas out, the more space between them, the better.
Keep your transmit power to the minimum necessary to make contact (this is actually in the rules…).

HF antenna would be a good candidate for being outside, as it'll need more room. Since it'll be running more power, you also want it away from the wiring in the home, which can act like an antenna and put all the RF into your electronics.
A wire antenna outside, on the opposite side of the house from the street, will be really low profile if done right.

 

[gearhead1961]

mmckenna - Much appreciated. On my recent scouting trip of the attic, I didn't see much in the way of metal except for the furnace and HVAC ducts. My initial thought is to try the scanner discone and the MW/FM antenna first and see how they work out. I'll place them at opposite ends of the space and as far away from the HVAC gear as possible. If they perform well, perhaps I can add the others. If they don't function well, we're off to Plan B (i.e. using the exterior of the house as an antenna farm). I am not convinced that the concrete tile roof will be my friend in this project but I guess there is only one way to find out.

The HF setup is another animal all together and its my intent to place that outside and hope for the best with the HOA and neighbors.

 

[mmckenna]

I'll place them at opposite ends of the space and as far away from the HVAC gear as possible.

With receiving antennas, it's not quite as important to have a lot of separation. It's the transmitting antennas you want spaced away from the others. I'd keep the 2/70 antenna at one end of the attic and the scanner antenna at the other. AM/FM antenna probably more towards the scanner end. You want to keep high transmitted RF levels out of the receivers.

I am not convinced that the concrete tile roof will be my friend in this project but I guess there is only one way to find out.

All building materials have some level of RF attenuation, some very very small, some substantial. Thin(ish) concrete tiles won't be a huge issue especially with all the RF flying around in your area. Probably not the best place if you were trying to listen to really weak stuff.

The MF antenna might suffer from issues being so close to all the electronic noisemakers in the house, but keeping wife/HOA happy is important, too.

The HF setup is another animal all together and its my intent to place that outside and hope for the best with the HOA and neighbors.

Thin wire is your friend. Most Karens don't look that closely.

I had a co-worker that bought a Harbor Freight flagpole and he insulated that from the ground. He installed an antenna tuner at the base in a planter box. Thin ground wires were stretched out along fence lines. He hoisted the colors and no one would dare complain. Meanwhile, he was running 80 meters AM...

 

[gearhead1961]

Thanks again for your insight on this topic. I will start the installation process in the next week or two. January is definitely the right time of year in Las Vegas to be crawling around in the attic. In the summer when it's 115 degrees in the shade, I cannot imagine the temps in the attic. I am guessing that my hair would spontaneously combust!

 

[krokus]

For MW & HF receive, have you considered a loop on ground?