Base Antenna for Newbie

[tweiss3]

I don't have a clue with antennas, but I did get the cars figured out, but there isn't nearly as much option with the NMO antennas.

I'm looking to bite the bullet and just get a base station for my office at home. I definitely need to keep GMRS, but want to add the Ham stuff, and listening to public works 800MHz. That being said, I may have an easy time with zoning, because I think they wrote an exception in the code for amateur radio (email response waiting). I'm starting my window shopping in hopes for a good Christmas.

My house is a split level with dual peak. I want to install the antenna off the higher peak, and pass into the attic under the eave.

Challenge 1:
I'm confused on what type of antenna. I know I don't want a yagi. Do I want a fiberglass amateur base station antenna, or a discone base station? I'd like the VHF/UHF and GMRS bands at a minimum, and good radiation pattern. This will be "roof" mounted, on the side at the peak, on a pole (probably 10'+-).

https://www.theantennafarm.com/catalog/diamond-x6000a-4879
vs
https://www.theantennafarm.com/catalog/comet-cx-333-1076
vs

https://www.theantennafarm.com/catalog/diamond-d3000n-5695

Challenge 2:
What else do I need to look into?
I was thinking grounding the support pole all the way to the ground and using a 10 grounding rod. I was also going to connect it (antenna)-(cable)-(multi strike under eave)-(cable through attic to office).

https://www.theantennafarm.com/cata...-50-ohm-629/20-1990-mhz-with-n-connector-635/

I'm looking for just 1 antenna at this time as I ease my way into this and DMR.

Thanks for all the help.

 

[gh6406]

Are you planning to Transmit with the antenna or just receive? If transmitting, you will not find a good antenna that covers GMRS, Amateur and 800 MHz all in one.

 

[tweiss3]

Yes, I will transmit on VHF Ham, UHF Ham and GMRS. 800 will be scanning only.

 

[mmckenna]

There are some decent dual band amateur antennas. Covering GMRS may be a challenge with a dual band ham antenna, though. You need to look closely at what frequencies it'll cover. Often lower gain antennas will have more bandwidth.

If you plan on scanning and using amateur radio, you really might want to consider separate antennas so you don't have to switch back and forth.

A discone can be a halfway decent option for scanners, although performance drops off as you get higher in frequency.

A good dedicated dual band amateur antenna is easy and not too expensive. Leave that hooked up to your amateur radio full time

An antenna for GMRS will work best if it's designed to work on the 462-468MHz portion of the band. A dedicated antenna hooked up to your GMRS radio is a good idea. Again, switching back and forth between antennas assures that you -will- forget to switch at some point and miss stuff.

Your antenna system is ONLY as good as your coaxial cable. Don't spend a few hundred dollars on radios and a few hundred dollars on antennas and then try to hook them up with the cheapest coaxial cable you can find. You really do need to look at it as an 'antenna SYSTEM" The system is your antenna, cable and everything up to the radio. Cutting corners is an awesome way to spend a bunch of money and then be disappointed.

Proper grounding is required by the National Electric Code. What you need will depend on the soil conditions around your home. Very difficult to tell you exactly what you need, this is what engineers are for.
But, you should have at LEAST one ground rod directly under your antenna. That ground rod —must— be bonded to your house electrical ground rod. Depending on soil conductivity, you may need more than one rod. Your antenna and mast need to be grounded and you really want that ground wire to run as straight as possible down to the rod. Sharp bends in ground wires will create 'jump off' points for lightning.
You do need to have a lightning arrestor where the cable enters the home. Ideally that should be right over the top of your ground rod, so you can run the ground wire down to the same ground rod.
Polyphaser is a respected brand in the industry.

 

[tweiss3]

The idea was to get something part 90 than could do GMRS so I don't have to go down to the car, ideally something like CS800D. But I may be forced into looking a buying a dedicated GMRS radio for my office.

Is is possible to install one fiberglass dual band over a dedicated fiberglass GMRS antenna, using the same mast? This is where my antenna theory knowledge really falls apart.

Is there a site that lists tested SWR of antenna across all bands? It sure would make a decision easier.

That being said, at home will mostly be Ham and DMR.

I apparently do have a problem with something you mentioned above. My house is 60+ years old and has no house grounding system. It's on the list to replace the panel and slowly do the whole house, but it hasn't happened yet. I guess I need to call my electrician friend and ask his opinion on overall grounding.

As for cable, I want going to cheap out, I was assuming 250-450 for cable, depending on final measurements. Either LMR 400 or Heliax.

All of that messy information combined, would I be better off starting with a quarter wave in the attic with a large ground plane and see how that goes? Only metal in the attic/on the roof are roof vents, and it's asphalt shingles. No metal trim on the house, it's wood sided. This is until I can get the whole house grounded/electrical updated and proper found the inside of the station.

 

[mmckenna]

The idea was to get something part 90 than could do GMRS so I don't have to go down to the car, ideally something like CS800D. But I may be forced into looking a buying a dedicated GMRS radio for my office.

For GMRS you need a radio that has Part 95 certification, not part 90.
But, yeah, we know…..

Is is possible to install one fiberglass dual band over a dedicated fiberglass GMRS antenna, using the same mast? This is where my antenna theory knowledge really falls apart.

With appropriate spacing, not only vertically between antennas, but away from the mast. Putting an antenna too close to the mast is going to couple it to the support as well as make it directional.

Is there a site that lists tested SWR of antenna across all bands? It sure would make a decision easier.

Reputable antenna manufactures are going to give you a bandwidth for the antenna. Usually it's how many megahertz of spectrum the antenna can cover under a set SWR, often 2:1.
Other than that, you'd need to buy and antenna, or find someone that has one, and do a sweep of it to see how it responds.

I apparently do have a problem with something you mentioned above. My house is 60+ years old and has no house grounding system. It's on the list to replace the panel and slowly do the whole house, but it hasn't happened yet. I guess I need to call my electrician friend and ask his opinion on overall grounding.

Yeah, you need professional help with that. And while an electrician can make sure your house electrical wiring and systems are properly grounded, lightning/RF grounds are a different beast.

As for cable, I want going to cheap out, I was assuming 250-450 for cable, depending on final measurements. Either LMR 400 or Heliax.

OK, good. Always hard when someone asks for antenna advice, then to find out they are using RG-58 to feed it.

Unless you have really long cable runs, LMR400 is just fine for most hobby use. Reasonably priced, easy to work with, and flexible enough to route through an attic or wall. Heliax can be hard to deal with in a residence.

All of that messy information combined, would I be better off starting with a quarter wave in the attic with a large ground plane and see how that goes? Only metal in the attic/on the roof are roof vents, and it's asphalt shingles. No metal trim on the house, it's wood sided. This is until I can get the whole house grounded/electrical updated and proper found the inside of the station.

And inch or so of shingles and plywood are not going to protect your antennas from lightning. Even a nearby strike can induce enough energy into an antenna and cable to do damage.

 

[cmdrwill]

Attic antenna.

Center is a 4S electrical box cover, radials are alum, NMO mount in the center, knock out.

 

[tweiss3]

With appropriate spacing, not only vertically between antennas, but away from the mast. Putting an antenna too close to the mast is going to couple it to the support as well as make it directional.

Forget that idea for now.

Reputable antenna manufactures are going to give you a bandwidth for the antenna. Usually it's how many megahertz of spectrum the antenna can cover under a set SWR, often 2:1.
Other than that, you'd need to buy and antenna, or find someone that has one, and do a sweep of it to see how it responds.

Yea, its not always listed, many of them just list 2M/70CM and leave it at that, which is annoying.

Yeah, you need professional help with that. And while an electrician can make sure your house electrical wiring and systems are properly grounded, lightning/RF grounds are a different beast.

I have to make some calls soon. Now is good a time as any to get a subpanel/dedicated circuits for my office as well as the garage.

OK, good. Always hard when someone asks for antenna advice, then to find out they are using RG-58 to feed it.

Nope, I know better than that. Won't trust RG-58 past the 12' that comes on mobile NMO mounts. With that, I don't want to be that close to the antenna on a 50/100W unit.

Unless you have really long cable runs, LMR400 is just fine for most hobby use. Reasonably priced, easy to work with, and flexible enough to route through an attic or wall. Heliax can be hard to deal with in a residence.

I wish there was a local radio store. Seems they have all disappeared.

I just found DX Engineering is out of Summit Racing, looks like I will have to pay them a visit when the showroom opens again.

And inch or so of shingles and plywood are not going to protect your antennas from lightning. Even a nearby strike can induce enough energy into an antenna and cable to do damage.

I'll look into this. I may be messing around with HTs for a while then. I'm sure the house rewire is going to be expensive.

And I thought my biggest issue was that I wasn't going to get above my 80'+ pin oaks.