Lets talk antenna for an 80

[Bruce Miller]

Qro

QRO = Increase power.

 

[treerootCO]

Can someone confirm that the mic is RJ-11 and the radio uses cat5e? I haven't purchased the radio and need to know what wires need to be run.

 

[nakman]

When have you guys with 70 cm used it yet?

Only once, and that was to access a repeater to listen in on an expedition portal net. Oh, and one time trying to learn how to cross-band repeat. that's it..

Mike I am not sure what the faceplate wire is, it sure looks like CAT5 but I don't think the connectors are that wide. I think Shark Bait has an extra cable, or you're welcome to come up and stare at mine if you want.

 

[Rock Dog]

what about a quad band antenna vs a dual band ? is there even more of a compromise ?
What about the quad band and radio vs the Dual band radio? it is abut $45 more which is like 25 bucks a band....

 

[Groucho]

Each time you spit the antenna up with a trap or coil you lose some of its radiating efficiency. That is not to say that it won't radiate effectively, it will just be less than optimal for any one band. Kinda think of it like this, in a sense you are tricking the antenna into thinking it is longer than it actually is for some bands, and not for others. Like silly putty you are asking it to take different shapes on.

In our discussion over the CB antennas, the 102" whip will far out-do the firestik (or similar) antenna, simply because you are putting more metal into the air.

The home brew 5/8λ 2M antenna will out perform a dual band antenna for 2M and 70CM. The difference might be unoticable for your purpose. Same thing goes for single band vs multi band yagis. A single band yagi will have maximized forward power and gain for the band for which it was designed. A tri-bander will have forward power and gain maximized to work for all three bands, not just one.

So to put it this way, if you use all four bands regularly, it will be more beneficial to you to get the 4 band antenna. If you think you will play mostly on 2M and for fun do 70 CM once in a while, stay with a dual bander. If you don't think anything other than 2M will be of use to you, get a mono-bander. Remember, too, that the quad band radios are usually for 10M FM, 6M FM, 2M FM and 70CM FM. 6M is said to be the magic band right now, with awesome opnings frequently allowing 1000 mile plus transmissions, 10M FM is not that busy.

Do what you like and what interests you. Go for it all. Play with it, its what makes the hobby fun!

 

[Rock Dog]

Thanks Nathaniel,
that really helps calrify it for me and explains why Nakman believed the "2 meter only" antenna reached out better, because it probably does. But at the cost on not being to do 70 CM.
for the extra 45 bucks i believe i will go with the FT-8900 and start with a dual band antenna mounted on the rear hatch.

It is all new and interesting at the moment. It may be i want to carry a 2M dual band and quad band antenna at some point just to have options, but baby steps for now.....

 

[Jacket]

Great info, but...

The antenna thing still baffles me. So many choices, so many mounts, so many different opinions. Since many of you have now had your setups for a couple years or more, can you sum up some of your experiences (good and bad).

I have at least a couple of options for the Tacoma:

- When I had my rear bumper built, I had Jed include an antenna tab on the drivers side for future use. I could mount something there.

- Front drivers side fender/hood mount. I currently have my radio antenna on the drivers side, and my CB antenna on the front ARB on the passenger side.

For reasons that others have concluded, a roof top mount would introduce some height issues. In the rear, my truck has a part-time can back, and a composite bed, so I don't have anything resembling a ground plane back there. So in my situation, is the driver front fender the best spot?

 

[Jacket]

The other thing that I'm having a hard time with is selection. Brands like Diamond, Comet, Larsen with similar and different models, and all kinds of options that I don't really understand. I could just pick a dual band NMO that has worked for someone else with a similar setup, but I'd like to understand it a bit more than I do. What is important in antenna selection? Height? Wavelength? Single vs Dual Band?

BTW - I'm leaning toward the Yaesu 7800.

 

[nakman]

Matt, my solution has been two antennas: both of mine are Comets, for no other reason than everyone else seemed to be buying them. I've got a longer SBB5 that is great for highway travel, on the way to runs, etc., and Moab. Then I've got the shorter SBB1 for wheeling in trees. Since my mount is up at the top of the hatch now, even the little one (think it's 18"?) gets bent over by trees, but it works very well for trail communication, and can still hit the repeaters.

But the longer one is better, no doubt about it.. proven several times this past summer on the Ghost Town & Ouray runs, as well as many monday nights talking to guys on the repeaters and on simplex. If you get a 7800 and a SBB5 antenna I'd be able to talk to you from your house to mine, but if one of us had a shorter antenna that would be more difficult, and impossible if we both had a short one. Not that ability to talk to me at my house should be any decision criteria for antenna purchase, just sayin...

Also I went to HRO and asked for a 2m only antenna, but they said you can't really get one, pretty much everything off the shelf is dual band these days.

 

[60wag]

I have an SBB1 mounted on the rear hatch. It works well and won't snag branches. I have been looking for a higher gain antenna for non wheeling use. The SBB5 is with a 2m gain of 3.0 is good but my likely next purchase will be a Comet CA2X4SR which is also a 40" antenna but touts a gain of 3.8 on 2m.

 

[Hulk]

Also I went to HRO and asked for a 2m only antenna, but they said you can't really get one, pretty much everything off the shelf is dual band these days.

I went through a similar process almost 2 years ago. Details here.

Long story short: I ended up with a 2m only antenna, the Larsen NMO 150-B. The good news is that it's inexpensive. The even better news is that it works great!

I have the Yaesu 7800 as well, but I only use the 2m. I mainly wanted the separation functionality so I could mount the faceplace in a tight space up front and the rest of the radio in the back. Otherwise, I would have bought the Yaesu 2800, which is a great radio that is 2m only.

I did a quick Google search. The Larsen is still available. Here's one place that has it for $30.

HRO sells the Larsen NMO-150CHW, a 2M half wave antenna, for $36.50. This is similar to the 150B in a shorter length (1/2 wave vs. 5/8). My antenna is at the top of page 4.

Here's a link to the Larsen catalog section with their 2M antennas.

Hamcity.com sells a Comet with the fold-over for $40: link.

 

[Hulk]

Here's the link to Larsen's multiband antennas, if you want to go with a dual-band antenna.

 

[Jacket]

Thanks for the insights. A few things I'm pulling out of your suggestions:

- Two antennas is a good idea. A "stubby" for the trails, and a tall (1/2 wave) antenna for traveling and local stuff. I assume you have quick disconnects to make it easy to jump back and forth?

- A single band, 2M antenna performs better than a dual-band? I'm mainly interested in the 7800 for the separation feature as well (as opposed to the dual-band), but at the same time it seems counter-intuitive to limit yourself to 2M use only when you could have both.

- No advantage to hood mount over rear bumper mount? I don't know enough about ground planes to know if the hood could act as a ground plane (to some degree) even though the antenna is out on a fender.

Since I'm talking about opposite ends of the rig, trial and error becomes less attractive since I'd have to rerun all the cable. But maybe I'm just splitting hairs here ...

 

[Hulk]

If you mount it on the rear bumper, will most of the length of the antenna have a parallel metal surface nearby (the back of the truck)? If so, this is not your best location. It will work better mounted on your fender where the fender/hood will act as a ground plane.

As for 2 meter vs. dual band, I'll quote Seldom Seen:

Not to muddy things up too much, but here is a 3rd option. If the shorty performs well on 2 & 70, skip the longer dual band all together and get an ant optimized for 2meter for backcountry use. Something like a 5/8 wave Larson MNO150. Dual band antennas are always going to be a compromise so having a dedicated 2meter for out in the bush, where you may need to reach way out and touch some one, might come in handy.

 

[nuclearlemon]

I assume you have quick disconnects to make it easy to jump back and forth?

-...

i run nmo mounts on mine. it's screw mount, but a wide thread so it unthreads/threads on real quick. i swap my antenna and radio rig to rig. i just have coax/ant mount and wiring harness for the radio that are permanent on the rigs.

 

[nakman]

I'd also point out that after having my antenna mounted on the edge of the hood for 1.5 years, the bend in the coax was so tight that it ultimately crimped the cable and stopped working. It turns out on an 80 (that is what this thread's about, right? ) there can be a much gentler curve to the coax when mounted in the rear hatch. So be mindful of your routing, and what kind of stresses the really skinny portion of the coax is going to see over time.

 

[Jacket]

If you mount it on the rear bumper, will most of the length of the antenna have a parallel metal surface nearby (the back of the truck)? If so, this is not your best location. It will work better mounted on your fender where the fender/hood will act as a ground plane.

I wondered about this too. Since its a pickup, I've got a lower profile than a wagon, but it's still probably 18-24" or so up from the bumper to the top of the bed. So for a 36"+ antenna, maybe I'd be fine, but a stubby would probably have some issues. Maybe I wouldn't need a stubby...

By the by - KDØFQQ as of last week

 

[Hulk]

By the by - KDØFQQ as of last week

Congratulations!

 

[Uncle Ben]

Congratulations!

Very Cool Matt! If you want to play with my VX-7 for a while your welcome to it! I'm not using it very often.

 

[Jacket]

Does anyone know what Bruce is talking about here:

I hate to see any antenna mounted to the swing out tire thing or the rear bumper where the antenna is behind the truck. That's like transmitting inside a tunnel.

But in the attachment, I see a rear bumper mount.