What is the best indoor/under roof base station antenna?

[DaveC1964]

I live in a town house ranch. Any kind of outside antenna mast is verboten. I want an antenna I could place anywhere maybe in the attic or in a spare room that I could use for a base station. Yes I know range will be limited but I want something that will just work. Could I just use anything like a mobile antenna or something else like a back of set or portable one? Are there any good solutions available? While I know it will not have great range I want the best one I can get in my situation. Any recommendations?

Thanks.

 

[chief21]

Most CB (27MHz) base antennas are about 18' tall... probably too tall for an interior room or attic. A mobile-type antenna likely won't work well without a good (read: fairly large) metal ground plane... as if it were mounted on a vehicle. Although I suppose that you might be able to rig something up by using chicken wire or wire garden fencing as a ground plane beneath the antenna.
Another option might be a "stubby" base antenna, such as the Tram 1499 or similar. These are not known to work well, but it might be better than nothing. Any of these options would need to be located as far away as possible from any interior wiring, ductwork, or similar materials.

 

[Dog]

I live in a town house ranch. Any kind of outside antenna mast is verboten. I want an antenna I could place anywhere maybe in the attic or in a spare room that I could use for a base station. Yes I know range will be limited but I want something that will just work. Could I just use anything like a mobile antenna or something else like a back of set or portable one? Are there any good solutions available? While I know it will not have great range I want the best one I can get in my situation. Any recommendations?

Thanks.

I am using one of these as a temporary base antenna. It works pretty well. Mine is outside on a patio at ground level though.

FireStik IBA-5 Indoor CB base antenna

 

[MDScanFan]

How tall is your attic? A simple ground plane antenna would work well provided you have some height and width to work with. A quarter wavelength at 27 MHz is only ~9' tall. If you use a coated wire then that length likely drops down to ~8'. I built one to span the CB band in my attic and it worked quite well. A PL259 flange connector and five scrap pieces of wire (one vertical and four ground wires at a slope). I just hung the wire from the peak of the attic. For the vertical element you can space apart a few wires to increase the bandwidth if needed.

(not my photos)

 

[prcguy]

You need a lot of ground plane under a mobile antenna for it to work and you could cover the attic floor with lots of chicken wire and plant the tallest mobile antenna you can fit in the attic in the middle of the chicken wire. Make sure the walls don't have aluminum foil backed insulation or stucco, which has a metal lath shield under it.

I've had good success with a V shaped dipole with the feedpoint on the floor and the two 9ft wires going up to the ceiling in a V shape. The same rules apply as above and you want to use a wall with no electrical wiring running inside.

Antennas like the Tram 1499 are complete junk and will reduce your range to about the same as a CB walki talki with 4ft whip. I think a walki talki would actually work better.

 

[KC3ECJ]

I live in a town house ranch. Any kind of outside antenna mast is verboten. I want an antenna I could place anywhere maybe in the attic or in a spare room that I could use for a base station. Yes I know range will be limited but I want something that will just work. Could I just use anything like a mobile antenna or something else like a back of set or portable one? Are there any good solutions available? While I know it will not have great range I want the best one I can get in my situation. Any recommendations?

Thanks.

I use a fibreglass antenna sold at a truck stop that's probably 2.5 feet long, it has a roughly 8ft copper wire hanging down the attic steps as the "negative" counterpoise side of the antenna making it a dipole.

Using a regular 4 watt handheld and coax I've gotten out good with it.

 

[Arkmood]

Always used a 102" whip magnetic base with as much metal available under it - a MFJ-945E helped also...

 

[FPR1981]

I've had varying degrees of good luck with indoor dipoles, as long as reflection isn't too big of an issue. Just depends on where you put them.

 

[FPR1981]

You need a lot of ground plane under a mobile antenna for it to work and you could cover the attic floor with lots of chicken wire and plant the tallest mobile antenna you can fit in the attic in the middle of the chicken wire. Make sure the walls don't have aluminum foil backed insulation or stucco, which has a metal lath shield under it.

I've had good success with a V shaped dipole with the feedpoint on the floor and the two 9ft wires going up to the ceiling in a V shape. The same rules apply as above and you want to use a wall with no electrical wiring running inside.

Antennas like the Tram 1499 are complete junk and will reduce your range to about the same as a CB walki talki with 4ft whip. I think a walki talki would actually work better.

God I second that! That Tram 1499 and the Workman version of it are JUNK! I've had small, cheap magnet mount mobile antennas outplay one. Not exaggerating. They're absolutely abhorrent.

 

[sloop]

I found this article and I am in the process of building one myself. Looks promising.
A Stealthy Homebrew Vertical Dipole Antenna Using Mobile CB Antennas
Written By: Scott Wolfington

 

[KOK5CY]

Had a close friend of mine use a galvanized large outdoor trash can upside down and put his mag mount antenna on the bottom . his swr was 1.5 to 2 and that was not bad . the friend was a great cber turned amateur operator .

 

[FPR1981]

Any magnet mount mobile antenna is only as good as the ground plane underneath it. You can use a nicer, larger magnet mount in the center of the attic, on a steel plate. You can use large sheet aluminum foil to create a larger ground plane underneath it and do halfway okay.

I mean, it isn't ideal, but if it's all ya got 🤷‍♂️

 

[drmurdoc]

Does anyone have experience with a magnetic mount installed on the refrigerator in the garage? Is that a big enough steel plate?

 

[FPR1981]

Does anyone have experience with a magnetic mount installed on the refrigerator in the garage? Is that a big enough steel plate?

Probably not, but possibly so. I've seen it work and I've seen it not work. I'd tell you to hook it up and check it with an SWR meter.

If it's a small enough antenna to sit on top of the fridge and not touch the ceiling then I wouldn't expect stellar performance. But could you get by with it? Yeah, probably.

 

[p1879]

My ignorance is manifest, but could a CB "Moxon" antenna work in this situation? (not moron, that's me) . Moxon is a directional antenna , however.
I do believe I have also heard of loops being used for 11m, but suspect must not be a good option as little heard about them.

Found an 11m Moxon plan, may well be too large, but has nice stats, if true:

Moxon Antenna Plan for 27MHz CB and Freeband Operation – Please Name My Blog

If I was confronting the situation, think I would use a long Skipshooter mobile antenna over a circle of resonant radials.

Lets hope we are heading into 11 Funtime again; will be the last such cycle for many, as radio hobbyists tend to be mostly the oldsters .....myself included.

 

[cralt]

Inverted V or just a normal dipole will work good for DX. Horizontal polarized.
For local you need vertical polarized. Try building the ground plane MDScanfan posted in in Post 4 but with as many ground radials as you can muster. #31 ferite near the antenna on the coax will help a lot with noise from all the switcher power supplies and cheap LED lighting.

 

[FPR1981]

Inverted and horizontal dipoles don't work "badly" for local talk, but they are somewhat directional, given that most other antennas are polarized vertically. Since you need an indoor solution, vertical polarization isn't an option. I would compromise on inverted V.

 

[KEWB-N1EXA]

These are my 2 outside antennas the V dipole is used for Listening and local Cb and the Silver rod 5/8 is my DX antenna.

I also have the tram 1411 that Has CB band - You could fit this under your roof - It does ok for Local CD talk but not DX.

I also have an old Antenna Specialist Mag mount sitting on a electrical box with Big Aluminum foil 110 inch radials in the attic
which holds a 1.2.swr and does work for local stuff.

When I say DX ~ that's working Ch 38 LSB and Above to talk to Europe when the Bands are open - To say this week was fantastic with
the Big Solar Storm Happening.
Pete N1EXA

 

[FPR1981]

Pete N1EXA

I love the magnet mount with foil radials as a solution. A Tram 3500 or Wilson 1000 on an electrical box with aluminum foil radials is probably as good or better than an attic dipole.

 

[KEWB-N1EXA]

I made the foil radials because I have to climb into the attic and deploy the thing. Was thinking Like on a moon landing the simplest antenna.
I folded the aluminum into about a 4 inch wide sections by folding it.. Then rolled it up connecting to the electrical box.
Just crawled across the insulation on a 2x6 board. placed the box down and unrolled the 4 radials. Its ugly but it works!

Never enough antennas !

Pete N1EXA
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