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KX6MWS
08-09-2011, 09:58 PM
I currently have only a FT-60r, and have had a lot of fun running with a mag-mount on my car. At home, I use a rubberduck antenna (not the OEM one, but a nice long Diamond one), and am now realizing that I have a much better signal in my car than at home! It's time for me to put a real antenna up on the roof!

I'm looking for recommendations. I can currently only drive with 5W; though eventually I will upgrade to a mobile radio + power supply for home use. (And leave the HT in the car).

I have been looking at a couple different options: (2 meters primarily, though I would like to keep 440 ability if possible)

(ground plane) http://www.hamradio.com/detail.cfm?pid=H0-008437
(http://www.hamradio.com/detail.cfm?pid=H0-008437)
(a different ground plane) http://www.hamradio.com/detail.cfm?pid=H0-001029

(j pole) http://www.hamradio.com/detail.cfm?pid=H0-008600
(http://www.hamradio.com/detail.cfm?pid=H0-008600)
I know I should avoid beams because I could overload on RX and end up not receiving anything at all. I also realize, there is risk of that happening with verticals as well, but I'm not overly concerned with that; I do have a separate scanner which I could always receive with instead.

There is also the option of my buying a second mag-mount, and putting it on the roof of my house with a steel plate. The element of the MFJ simple vertical (here http://www.hamradio.com/detail.cfm?pid=H0-001029) doesn't look much different than the MFJ magmount I already have on my car; it just has the radials to make up for not being attached to a car!

Is there much difference in these antennas? I know these are all on the low-end of available prices; I've seen some pretty expensive verticals on the market. On a 5-watt HT (which will later be replaced with about 50 watt mobile), would I see much difference in these at all? I suppose anything on my roof is better than the rubberduck in my house.

Thanks!

WB2WIK
08-09-2011, 10:06 PM
Those should all work about the same.

Clamp it to a mast, get it up as high as possible above the roof and everything else around, feed it with low-loss coax if possible, and have fun.

Yes, HTs are often pretty "overloaded" by the strong signals provided from outdoor antennas, but that's just one of those things. See what happens, you'll probably be pleasantly surprised.

W6CD
08-10-2011, 12:58 AM
I used the Arrow J-Pole mounted at 15' to a radio shack mast bolted to my patio cover - with a hand-held. Now have a 50W radio and power supply, using the same antenna. Works fine for local repeaters. Simple, low cost, and rugged.

KI6A
08-10-2011, 07:40 PM
+1 on WB2WIK
-Use the best (low loss) coax you can buy (this may cost more than your antenna)
-Get the antenna up as high as you can - altitude is everything on 2m
-With a great antenna system, 5w is more than enough

Keep it simple and stick to the above principles and you can't go wrong. Here are a couple of tidbits I learned putting up my own base antenna:
-"top fence railing" makes a great mast (buy at local hardware store)
-Look into a grounding system to protect against lightning strikes (one of my Elmers would drive the rail into the ground and build his mast on that - I use a copper clad ground rod connected to the mast + surge protector right before entering the house)
-A great quality, 2m only antenna is the CP22E from Diamond (around $50)
-Play around with 70 CM before you spend a lot of money on a dual-band base antenna - there isn't much action in the Sacramento area where I live, due to the PAVEPAWS system (careful, this topic is bound to produce some emotional responses when brought up on your local repeater)

Good luck & 73!

--Mitch

KD8NPB
08-10-2011, 07:51 PM
I use a Diamond F22A that I picked up used for $40.

It's fed with off-brand RG8U, about 80 ft of it.

Even with all the losses, I can hit a repeater that's 35 miles away with full quieting. It's about 30 ft off the ground.

My advise for a rugged base antenna:
3 ft TV tripod, lag bolted through the roof into some 2x4s on the other side
1.25" EMT Conduit, slipped into a piece of 1.5" EMT Conduit with a bolt+lockwasher+washer+nut. They're 10 ft tall sections, I've got mine with 5 ft of overlap (so 15 ft)
3-way guy wire mount, mounted a few inches below the top, 3/16 aircraft cable with turnbuckles at the ends, loops set into rafter boards

I use a setup like this for a Maco V58 10m vertical. It's survived icing, snow, and heavy winds with zero problems. Just be sure the base tripod is installed well, as it'll be bearing the brunt of the force.

KX6MWS
08-10-2011, 08:23 PM
Thanks. This will be my first rooftop antenna installation. I was considering buying the antenna first and trying it out in the attic before moving on to putting it on the roof; it should at least be better than the rubberduck inside the house. I would be happy with any setup that works as good as or better than the magmount does on my car. I can get from Emeryville, CA to Palo Alto, CA (40 miles) with my HT, and the 'guy' (whoever he was) said I was almost full quieting. Reducing to 3 watts, I was still readable. However, inside my house (which is only 10 miles away from the same repeater), at a full 5 watts I'm a bit scratchy, unless I hold the radio over my head! (Using a Diamond RH77CA )

I just don't want to go outside or in my car when I want to go online.

KJ4VOV
08-10-2011, 08:32 PM
The Arrow aluminum J-Pole is a pretty good choice, and the plans for it are published if you have basic machine shop skills and want to make it yourself.

Your biggest problem is going to be feedline loss.

Even on 2m, using something like RG-8X is going to introduce significant loss at anything over 25' or so. With only 5 watts every little bit of loss is really going to hurt.

You could mitigate the losses with higher quality coax, such as LMR-400, but the cost of the coax will about equal the cost of a decent 2m rig (used) with more power. Or, you could increase your power with a small "brick" amplifier, and not worry about the losses, but again, the cost would be about equal to a good used 2m rig.

KI6A
08-10-2011, 08:38 PM
Just to offer perspective: I've been able to QSO simplex 80+ miles on 0.5 watt with a Ringo Ranger II (reasonable antenna, but not "top of the line") about 10' above my 2 story house (I think the base is about 35' off the ground), with 45' or so of Belden 9913 - the reports are "some noise" at 0.5 w, and are usually full quieting at 5w up to 60 or 80 miles.

It just depends on who you want to talk to :)

Depending on your roof/wall composition, you may want to stick with an outside mount, but it shouldn't take much to hit that 10mile repeater (attic should be fine). Maybe others who have tried an attic mounted antenna could chime in...

N3JPB
08-10-2011, 08:43 PM
Exactly the same experience that I have had with the ARROW - OSJ-146/440. Started with a Yaesu VX-7R (with the antenna in the attic) then a Yaesu FT-7800 and now a Yaesu FT-8900 with the J-pole on the roof. 7 years of excellent service.

John (N3JPB)

N7SMI
08-10-2011, 08:44 PM
I put up a Comet GP-6 as my base antenna and have been very pleased. It costs a bit ($150), but is a very well-built high gain antenna. I have mine mounted on a fence top-rail mast at the peak of my house about 22' high, and the cable run is 60' of LMR-400. I can easily get to and from repeaters 50-70 miles away with a 5 watt HT, though I typically run a 50 watt mobile. I have listened to many satellites and typically get clean signals in from repeaters over 100 miles away... and this is over and around significant terrain.

KJ4VOV
08-10-2011, 09:09 PM
Exactly the same experience that I have had with the ARROW - OSJ-146/440. Started with a Yaesu VX-7R (with the antenna in the attic) then a Yaesu FT-7800 and now a Yaesu FT-8900 with the J-pole on the roof. 7 years of excellent service.

John (N3JPB)

They really are very good antennas. Maybe not the "best", in terms of gain, but they're robust, durable, inexpensive, tough, (did I mention that they're pretty sturdy?) and, bottom line, they work. I usually buy materials for a half dozen at a time and, using the published plans, build them as needed. It takes about 30 minutes to build one, costs about $18 in materials, and they last almost forever. I keep two in my truck for emcomm and public service work, and I've donated several to new local hams as a "welcome to the hobby" gift.

N6DCN
08-11-2011, 12:17 AM
I have had one of these for years. 2m-70cm Works great. never a issue.

OPEK UVS-200

http://www.eham.net/reviews/detail/2887

WB2WIK
08-11-2011, 12:25 AM
Just to offer perspective: I've been able to QSO simplex 80+ miles on 0.5 watt with a Ringo Ranger II (reasonable antenna, but not "top of the line") about 10' above my 2 story house (I think the base is about 35' off the ground), with 45' or so of Belden 9913 - the reports are "some noise" at 0.5 w, and are usually full quieting at 5w up to 60 or 80 miles.

It just depends on who you want to talk to :)

Depending on your roof/wall composition, you may want to stick with an outside mount, but it shouldn't take much to hit that 10mile repeater (attic should be fine). Maybe others who have tried an attic mounted antenna could chime in...

Attic mounted antennas can work fine, or not. Depends on the construction materials of the house.

Here in So. Cal., many houses have stucco exteriors (survives earthquakes well, and that's why it's so popular) and if you have a stucco sided house, an attic antenna will work very poorly. Putting the same antenna on the roof above all that boosts signals 20+ dB.

But "wood" (as long as there isn't foil-backed insulation in the attic) is fairly transparent to RF.

KX6MWS
08-11-2011, 06:46 AM
How much grounding do I need? I've read things from just a simple grounding wire to reduce static buildup vs putting in a 8' grounding stake. (I live in Sunnyvale, CA where there's rarely thunder heard.)

What kind of grounding setups for small 2-meter antennas do you guys have?

W4ODY
08-11-2011, 07:26 AM
I highly recommend the Ringo Ranger I and Ringo Ranger II vertical antennas by Custcraft. I just recently replaced my 40 year old Ringo Ranger I with another Ringo Ranger I as I really like this antenna. A good place to buy high quality, low loss coax is from www.radioworks.com (http://www.radioworks.com); their prices are the best I have found and their service is great. The antenna is easy to put togeather and to mount.

KJ4VOV
08-11-2011, 07:52 AM
How much grounding do I need? I've read things from just a simple grounding wire to reduce static buildup vs putting in a 8' grounding stake. (I live in Sunnyvale, CA where there's rarely thunder heard.)

What kind of grounding setups for small 2-meter antennas do you guys have?

"Rarely" does not equal "Never", and a good ground system isn't just an electrical ground, it's also an RF ground. At the home QTH I use a standard 8' x 5/8" grounding rod driven into the ground just outside my shack window and connected to the shack grounding buss with 2 gauge stranded copper cable, kept as short as possible (about 8 foot) and with as few bends as possible (one bend as it exits the shack and goes down to the rod). Excessive? Not to me. In fact, I've considered using two rods, to improve the grounding during this dry weather we've been having the past year or so.

WB2WIK
08-11-2011, 02:49 PM
"Rarely" does not equal "Never", and a good ground system isn't just an electrical ground, it's also an RF ground.

Unless your rig is sitting on the ground surrounded by and connected to a radial field, you'll never get an "RF ground" on two meters. 8' is "forever" at a frequency that high. You might have an RF ground on the low bands, though. A 2m antenna doesn't need an RF ground, nor does the equipment it connects to, as 2m antennas are self-contained and quite ground independent.


At the home QTH I use a standard 8' x 5/8" grounding rod driven into the ground just outside my shack window and connected to the shack grounding buss with 2 gauge stranded copper cable, kept as short as possible (about 8 foot) and with as few bends as possible (one bend as it exits the shack and goes down to the rod). Excessive? Not to me. In fact, I've considered using two rods, to improve the grounding during this dry weather we've been having the past year or so.

A bunch of rods spaced far apart and interconnected is better than one. However a "lightning protection ground" is something applied to all transmission lines, rotator cables, etc. and all terminated outside. The ground attachment to the station hasn't much to do with lightning protection, and can actually make things worse in some cases, such as if you didn't create a single point ground that's also connected to the electrical utility ground at a common point.

KJ4VOV
08-11-2011, 05:04 PM
Unless your rig is sitting on the ground surrounded by and connected to a radial field, you'll never get an "RF ground" on two meters. 8' is "forever" at a frequency that high. You might have an RF ground on the low bands, though. A 2m antenna doesn't need an RF ground, nor does the equipment it connects to, as 2m antennas are self-contained and quite ground independent.



A bunch of rods spaced far apart and interconnected is better than one. However a "lightning protection ground" is something applied to all transmission lines, rotator cables, etc. and all terminated outside. The ground attachment to the station hasn't much to do with lightning protection, and can actually make things worse in some cases, such as if you didn't create a single point ground that's also connected to the electrical utility ground at a common point.

I see that I should have been more detailed in my response. I wasn't speaking about any particular band when I spoke about the station ground also being an RF ground. It was more of a general statement pertaining to the entire shack. I also should have stated that all cables at my shack are indeed grounded (using lightning arrestors - which are actually worthless in the case of a direct strike, but that's a topic for a different thread) to that same rod before entering the shack, thus maintaining the single point ground.

However, this thread isn't about me and my shack, it's about the OP's shack, and I firmly believe that a good grounding system is an essential building block of any shack, and should be one of the first steps taken when you start setting your shack up at home.

K6CPO
08-11-2011, 08:01 PM
I used the Arrow J-Pole mounted at 15' to a radio shack mast bolted to my patio cover - with a hand-held. Now have a 50W radio and power supply, using the same antenna. Works fine for local repeaters. Simple, low cost, and rugged.

Another recommendation for the Arrow ground plane here...

I started out with an FT-270R 2 meter HT and the original rubber duck antenna, I then picked up a simple Comet dual-band (looking ahead for when I'd have a dual-band radio) and used that stuck to a cookie sheet on the top of my desk. I then bought the Arrow GP-146/440 (again looking ahead) and stuck it up on an 18 ft pole. The coax run was 50 feet into my shack. I used this with the FT-270 for a good while and was able to hit most of the repeaters around town with no problems. I then added an FT-1900R which went into my truck with the Comet mag-mount, although I used it in the shack once or twice. I'm now using a FT-7900 dual-band radio in the shack with the Arrow antenna...

The Arrow antenna worked perfectly with the HT and I never experienced the overloading mentioned elsewhere in this thread. It also works well as a receiving antenna on other bands, including 220 (the FT-7900 doesn't have the ability to TX on 220.)

KF5FEI
08-11-2011, 08:49 PM
I've got one of the mid-sized Tram 2m / 70cm colinears sitting on a 10-foot pole in the yard next to the house. Even with 50 feet of vintage RG-8X I can hit our club repeater easily with 1 watt and have full quieting. Can't wait until I get it on the roof with some decent coax.

N6DCN
08-11-2011, 11:42 PM
Here is a pdf file of a J pole that I have built. As a matter of fact I have built 4 of them. Including one for 6m. Work real well and cheap

http://www.dxzone.com/cgi-bin/dir/jump2.cgi?ID=3482

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