Mobile Base Station setup help.

[Capt Crunch]

Your antenna may be hooked up to a metal fence but that's not really a RF ground.

Get four lengths of wire about 9ft long, attach them to each side of the mount and stake the other ends to the ground. See how that goes. You'll probably need to retune the antenna.

I was wondering about that. I was thinking to "de-ground" the mount from the fence rail altogether and doing a copper rod ground straight to the mount. The radio is tuned flat across the channels and its nice and quiet and I can hear ok and I get out, but it seems to be about 1/2 of what my setup does in the mobile with receive and transmit. And thats when the jeep is against the other side of my house and that has an apartment building next door, so its blocked in. I have base stations around me and they are getting half of what I usaully do and my whip is on an open side where they are. They are also showing about half of what they do. After searching for "mobile cb antenna on fence rail", I was reading last night and found out more about ground planes and found a calculator so I am guessing what you are saying is the same result I got with the calculator and it said the same length as the whip. I read sometimes that fencing ground is not a good thing and can continue all around the fence, that's why I was thinking of putting some rubber between the mount and fence and do a copper rod ground. I understand what you are saying, however when you say stake them can that be anywhere because if you see the mount pic(s) in the other post the right side of the fence is a cement sidewalk, on the left side of the fence is a yard and I really don't want to stake all wires there as the landlord is old and mows that area and I don't want him to have to worry about that stuff and he could run over it LOL. Hence the reason I was thinking about the ground rod in the ground right next to the fence post. if you are experienced, do you think I should try de-grounding from the fence? It is showing the mount is connected to everything including the fence. I added the mount pics here. Suggestions welcomed.

 

[BJ radionut]

 

[Capt Crunch]

View attachment 43538

Nice, read about all that but my issue is where the antenna is. I would have to find a way to put posts in the ground on the earth side and two on the walkway side attached to the house but I can't that as it will block the passage way. I can't put out the 4 wires like that, unless I have them in a straight line on the earth side of the fence close to the fence because he mows the lawn and is old and I don't want him to be able to run anything over LOL.

 

[Riverman]

Capt,
Four wire radials is definitely a problem given the location. However, two radials work really well. If you can stick your antenna on a 10’ pole of some sort, you can then run two 102” wires down to your fence at roughly 45 degree angles and will be good to go. (Insulate the wires from touching the fence.) I think you’ll see a big boost in performance.

 

[Capt Crunch]

Capt,
Four wire radials is definitely a problem given the location. However, two radials work really well. If you can stick your antenna on a 10’ pole of some sort, you can then run two 102” wires down to your fence at roughly 45 degree angles and will be good to go. (Insulate the wires from touching the fence.) I think you’ll see a big boost in performance.

That I may be able to handle. The fence itself is like 6ft high and I can find a 10ft pole somewhere to clamp onto a post. I take it you are saying to connect from two wires from each side of mount in line with the fence rail and attach wires to fence at 45 degree angle, not touching fence. I didn't want it too high right now as I stick my head out my window to disconnect the coax from the antenna when there's lightning around, but 10ft is right at my window so all good. Can I use regular covered speaker wire or something different? I do have covered hardwire in a couple different gauges if one is better than the other. Probably have 6 to 20 gauge hardwire in rolls at work. One other thing in diagram, is the fishing line there so the wire isn't touching anything or is it just for mounting or both?

 

[Riverman]

That I may be able to handle. The fence itself is like 6ft high and I can find a 10ft pole somewhere to clamp onto a post. I take it you are saying to connect from two wires from each side of mount in line with the fence rail and attach wires to fence at 45 degree angle, not touching fence. I didn't want it too high right now as I stick my head out my window to disconnect the coax from the antenna when there's lightning around, but 10ft is right at my window so all good. Can I use regular covered speaker wire or something different? I do have covered hardwire in a couple different gauges if one is better than the other. Probably have 6 to 20 gauge hardwire in rolls at work. One other thing in diagram, is the fishing line there so the wire isn't touching anything or is it just for mounting or both?

Yes, the wires are in line with the fence. Speaker wire is fine. The fishing line is used to keep the wires from touching the fence. Any non-conductive material will suffice. Start with the wires a few inches longer and adjust their length for lowest SWR.

 

[Capt Crunch]

Yes, the wires are in line with the fence. Speaker wire is fine. The fishing line is used to keep the wires from touching the fence. Any non-conductive material will suffice. Start with the wires a few inches longer and adjust their length for lowest SWR.

OK. Going to take about a week to get the clamp if HD don't have them. I am going to get 1 inch blackpipe from work. I am going to get a 10ft piece and add an elbow and another 4inch piece at the top like a perch, so I can use the same mount. I do have tuning on the whip itself, should I try that at first? If I use covered hardwire what gauge should I use?

 

[Riverman]

OK. Going to take about a week to get the clamp if HD don't have them. I am going to get 1 inch blackpipe from work. I am going to get a 10ft piece and add an elbow and another 4inch piece at the top like a perch, so I can use the same mount. I do have tuning on the whip itself, should I try that at first? If I use covered hardwire what gauge should I use?

Ah, yes, if the whip length is adjustable, I’d use 103” wire radials and tune for SWR using the whip. I like 14 or 16 ga wire personally but smaller works too.

 

[Capt Crunch]

Ah, yes, if the whip length is adjustable, I’d use 103” wire radials and tune for SWR using the whip. I like 14 or 16 ga wire personally but smaller works too.

Cool, thank you.

 

[Riverman]

Cool, thank you.

You’re welcome.
My experience has been antennas using two radials aren’t completely omni-directional but are close. You might see a slight increase in performance in the direction of the radials. Or not. Other factors are in play such as the proximity of the house. Getting the antenna higher will help.

 

[Capt Crunch]

You’re welcome.
My experience has been antennas using two radials aren’t completely omni-directional but are close. You might see a slight increase in performance in the direction of the radials. Or not. Other factors are in play such as the proximity of the house. Getting the antenna higher will help.

Thanks again. Do you think I should try to "de-ground" the antenna mount from the fence by using rubber where its mounted or leave it as it is?

 

[wjm1129]

Leave it as is. Won't make any difference.

 

[Riverman]

Thanks again. Do you think I should try to "de-ground" the antenna mount from the fence by using rubber where its mounted or leave it as it is?

That’s a flip a coin question. Some say yes. Some say no. It seems it would make a difference, but I’ve never seen any myself. I agree with wjm.

 

[Capt Crunch]

That’s a flip a coin question. Some say yes. Some say no. It seems it would make a difference, but I’ve never seen any myself. I agree with wjm.

I know exactly what you are saying. I read nine different things about this same subject already. I try to balance it all from what I have already learned and then all the other reads, after awhile I try and narrow one down that alot of people are agreeing with LOL. I always thought added ground planes were bs until I read more and found it does make a difference, sometimes. Even was reading on Dipoles for 11 meters. I'm going to set this up and see what happens. I am a mobile use person and just got that all perfected the last couple years being off and on since the 70s. Havn't had a base in many years and actually pretty fun learning new stuff for base use with restrictions. Been at this location for 16 years and I'd like to do a 30ft pole with a A99 in the yard but it's not my house and even though they probably would let me, I don't want to intrude into their lives or property that much. Old fashioned old italian couple and who love it here and what they have. So if I can get this right and intrude as little as possible, I'll be happy. Might try a pole on the fence post with an A99 down the road but seeing how this goes for awhile first. Getting a new mobile radio and trying this to have something to listen to in the house.
P.S.Sorry for rambling had some time to kill LOL. Thanks.

 

[Riverman]

I don't want to intrude into their lives or property that much. Old fashioned old italian couple and who love it here and what they have.

Nice of you to take their feelings into consideration, Capt. A lot of people could learn from you.

I think getting your whip up in the air a little with a couple of wire radials will be an improvement. In the meantime, you’re “on the air” and that’s what counts.