JPole Antenna for Baofeng?

[Hydrogen18]

I purchased a Baofeng BFF8HP recently, and I am considering buying a JPole Antenna to mount on my roof. I currently have the radio connected using RG-58 coaxial cable to a 26 inch Radio Shack antenna on a vent pipe on my roof (yes, Radio Shack came through for me in this day and age), and I'm wondering how much improved performance adding a Jpole would grant me, and if the Jpole is the best idea, or if I should go with a different antenna. I also would like to know the best coax cable to use with my current situation in mind. If someone could tell me how high I should try to mount the antenna too, that'd be great. Advice on grounding it would be much appreciated as well. One last question, considering I'm planning on buying a 2 meter antenna, is there something I can use to connect and switch between additional antennas that would work with my Baofeng? All help is appreciated, thank you in advance.

 

[mmckenna]

I purchased a Baofeng BFF8HP recently, and I am considering buying a JPole Antenna to mount on my roof. I currently have the radio connected using RG-58 coaxial cable to a 26 inch Radio Shack antenna on a vent pipe on my roof (yes, Radio Shack came through for me in this day and age), and I'm wondering how much improved performance adding a Jpole would grant me, and if the Jpole is the best idea, or if I should go with a different antenna.

J-poles are effectively a half wave antenna and have zero gain unless you add a ground plane under them. with a perfect ground plane, you get about 2.4dB.
Not impressive, and you can easily do better.

I also would like to know the best coax cable to use with my current situation in mind.

Best? How much money have you got?
Seriously. "Best" means different things to different people. We could tell you that 6 inch rigid is "best", but unless you recently won the lottery, you can't afford it.
RG-58 might be "best" to someone else with a limited budget.

You'd have to give us some parameters to work with here.

If someone could tell me how high I should try to mount the antenna too, that'd be great.

A higher antenna gives you more distance to the "radio horizon". The farther your antenna can see, the farther you can talk. Again, it's a budget thing. Getting an antenna up high cost money, takes work and can be risky. If you have a $10 budget and are 90 years old, the answer would be different from someone with a $10,000.00 budget and was an experienced tower climber.

Advice on grounding it would be much appreciated as well.

National Electric Code says it has to be grounded. If you took a lightning strike, or even if one hit nearby, you run the risk of a fire. If this sets something on fire, your homeowners insurance gets involved. They look and "whoops, doesn't meet NEC", then you are totally out of luck and likely flat broke.

Many people assume that a direct lightning strike is the only concern. It isn't. Even a nearby strike can induce enough energy into your antenna to damage your radio, cause injury, start a fire, trash your home, etc.

Your mast/support structure needs to be grounded and bonded to the homes electrical ground. You also need to have your feed line grounded and bonded to the same electrical ground. Again, your budget and experience level would help us understand a lot about what you are capable of.

One last question, considering I'm planning on buying a 2 meter antenna, is there something I can use to connect and switch between additional antennas that would work with my Baofeng? All help is appreciated, thank you in advance.

Yep, an antenna switch. You can either have one inside your home, or a remote one.
One inside your home is cheaper.
One outside on your antenna mast is more expensive, but lets you only have to run one coax down to the radio. All the switching is done up high.

Give us an idea of what your budget is, what your experience level is, and how comfortable you are working at heights, then we can give you more detailed answers.

Getting a proper antenna up as high as you can with low loss coaxial cable will improve your experience a lot. Doing it correctly is important. Doing it safely is paramount.

 

[Hydrogen18]

Thank you for taking that into mind, I will try to answer your questions to the best of my abilities. My budget for antennas and coaxial cable at the moment would be at a maximum probably $400, but if I needed to I could work around that, I'm not quite sure exactly how much money would be required. I'm a beginner when it comes to ham radio, and I am able to work off of my roof, and most likely somewhat higher if I need to. I'll be sure to add more detail in later posts, thank you.

 

[wyShack]

I wouldn't get to 'crazy' on the antenna. Remember you need to hear (receive) as well as talk (transmit). While handhelds have sensitive receivers, they are not designed with a good front end due to the limited space for filters, ect. Once you get a decent antenna hooked up, you will likely start having issues of hearing 'too much'. A good compromise would be a 1/4 wave or J-pole up about 20-30 feet. Use a mid range coax (I suggest RG8). That will be a large improvement over the stock or any indoor antenna and if you want more after that, I would suggest a mobile/base type radio that has a better receiver.

RG58 coax has quite a bit of loss -OK for mobile but not good for any run over about 15-25 feet.

73

 

[mmckenna]

That's some good advice above.

I'd put $200 into a mobile radio, another $60 into a 12 volt 15 amp power supply and the rest into coaxial cable and a proper base station antenna.

I agree, no need to go nuts.

Keeping the antenna low will save you some money on coaxial cable. RG-8 or LMR-400 would be a good choice. Unless you have done coaxial cable termination before, order it with the connectors you need already in place. Learn how to do them properly later on. No need beating your head against the wall on your first try.

Diamond X50NA would be a good choice: Diamond® Antenna ~ X50NA Dualband Base/Repeater Antenna It's dual band, so it will work with 2 meters and 70 centimeter bands.
- For the love of Pete, avoid any e-Bay no-name specials. There is no magic pixy dust that makes antennas work. They are all bound by the laws of physics. Go with a decent antenna now and it'll serve you long into the future. Buying a cheap Chinese made Tram/Browning/No-Name special might save you a few bucks, but it'll bite you in the rump later. You don't need those headaches now.

Mount it up above your roof in the clear. A small antenna like this can use simple TV antenna mounting hardware. Again, no need to beat your head against the way trying to string up a 50 foot tower. Small incremental steps are the way to go.

Ground the antenna mount to a ground rod directly under the antenna and to the house ground rod. Ideal to have them both close by. Use #6 (6 gauge) or larger wire for the ground.
Install a PolyPhaser type supressor device just before the antenna cable enters your home. PolyPhaser IS-50NX-C0 - Flange mounted, dc block - Polyphaser
Again, don't go cheap on this stuff.

Ground that PolyPhaser to the ground rod using #6 or larger wire.

For the coax, you'll need RG-8 or LMR-400 long enough to reach from the antenna to the PolyPhaser where it enters your home. You'll want Male type N connectors on each end. Use Type N connectors since they are rated for higher frequency than the UHF type connectors. Doing this now will prevent you from having to upgrade later on. Also, the type N connectors are designed to be waterproof, where the UHF/PL239/SO239 connectors are not. You still need to waterproof your connections, though.
You'll need another length of coax to reach from the PolyPhaser to your radio. N Male to N Male will work.

Do NOT connect the RG-8 or LMR-400 directly to the radio. This will put unnecessary strain on the antenna connector on the radio. It's a common way radios get damaged.
Instead, order a short length of LMR-240, RG-58, etc. type cable with a Female N connector on one side and a connector to match your radios antenna jack on the other. For amateur grade radios, this is often a UHF type male connector.

When you are done, water proof -ALL- the outdoor connections. Don't skip this step. Again, -Don't. Skip. This. Step.-
Put a layer of electrical tape over all the connector and down the coaxial cable a few inches. Use scissors to cut the tape. Do -NOT- pull the tape to break it. This stretches the tape, but not the adhesive. Doing this will cause the tape to come unraveled.
Follow that up with a moldable sealing tape over the connectors. Do not block the "weep" holes on the bottom of the antenna, but make sure the connector is covered and sealed up past the threads on the antenna.
Do all your outdoor connections the same way, even if they are protected under the eaves.
Follow up with another layer of electrical tape. Wrap "half lapped and back" all they way over the previous layers and down the cable a bit. This means each wrap of tape should overlap the previous by half way. When you get to the end, wrap it back in the opposite direction.

This is how the professionals seal coaxial cable connections. It works, it's been proven. Avoid coax connector "fillers". These just make a mess and don't always work.

Not doing proper sealing will allow moisture into your cable/connectors and will cause corrosion. This will destroy your coax. Don't install coax without sealing the connections properly.

Make sure your coaxial cable is well secured so it isn't flopping around in the wind. Use UV rated black ty-wraps to hold the cable to the support mast. Do not use the non-UV rated ty-wraps or you'll be up there replacing them in short order.

Connect up your radio. If you or a friend has an SWR meter, check everything out for proper function. If you do everything right, it should all work very well.

This dual band antenna will work well for the amateur bands, but it'll also work well for VHF and UHF scanning. Might work well on 700 and 800MHz well.

Just make sure you ground everything properly. Take your time and do it right.

 

[Rred]

Find out the specs for the cable you are thinking of using. And roughly how long the cable run to the roof antenna would be. You may be surprised. For instance, if you need 100 feet of cable and the cheap cable from Rat Shack has a loss (on the frequency you will be using, perhaps 440 MHz?) of 3db per 100 feet?
You will lose 3db of signal strength in that cable. You may need a much more expensive cable to knock that down to a 1db loss. If the cable loss is higher than the antenna gain...your net result is that the roof antenna will give you a weaker signal than your rubber duck!

So getting a "mobile" radio with higher power, and a more sensitive receiver with less noise, and an adequate power supply, may be the only real way to improve things, even with the roof antenna.

 

[FKimble]

I'll second the Diamond x50 antenna mentioned above. Mine is in the attic, about 25 feet above ground level. Very pleased with it's performance. 4.5dBi gain. It also gets very good reviews over on eHam. Last time I checked they were less than a C-note. Comes with either a "N" connector or a UHF. Coupled with either Davis RF Bury Flex 9914F or LMR400, avoid coax with words like 400 "type" or 400 "like" in the description, for very little signal loss even in a 100ft cable run. Like the RF Davis, the LMR400 comes in a "F" or Flex version also, very good if the coax run must make some tight turns in its run.

 

[TheSpaceMann]

Before you go out and spend a bunch of money on an antenna, you can just build a simple 2 meter or 440 ground plane for just a few bucks! It's performance will be similar to a J-pole. Lots of plans for it are online! 2 meter 1/4 wave Ground Plane or BUILD A GROUND PLANE ANTENNA FOR 2 METERS AND MORE - SIMPLE AND EASY!

 

[cmdrwill]

Forget the j pole, the above mentioned DIY ground-plane will work just as well. As always use a good quality RG 213 cable at minimum. You will save money and be happy.