Ham Radio Antenna Mount Advice

[werrea]

Hello everyone. I have been searching for a more solid solution to replace my mag mount set up on the roof. I like the idea of having it as high as possible and have seen a few of you put it on the rear hatch.

Is this the best option for a hard mount? I have a 2M whip, so screwing onto an existing base would be best. To be honest, I get a lost in the HAM language and set up.

So please show me your set up. If on the hatch, when opening the hatch does the antenna hit your roof rack?

I do plan on getting a larger rack for base support of a RTT.

Thank you in advance.

Anthony

 

[ntsqd]

Need to consider the base plane for most antennas. In 2M that's an ~19" radial around the base of the antenna. There are NMO bases with radials for using a base-plane antenna as a base station antenna. I have two of them for use at outdoor events where I'm semi-stationary (meaning I might be there all day with nothing to do or I might have to quickly move out). I put one on the end of a 6'->12' painters extension handle to get a little extra range/clarity in Simplex while allowing rapid put-up and take-down. I don't think these will work while moving, but they may - never tried it.

Usually I just drill a hole in the center of the roof, so pictures of that probably won't be much help. 60's are kinda messed up, they have a center rib in the roof that isn't wide enough for the antenna, so a permanent mount has to be offset. That bothers my CDO (like OCD, but with the letters in the right order). The plan for mine is to mount the antenna on the roof rack. I'll make sure that one way or another that it has an adequate base plane.

 

[MANUCHAO]

I just recently got me a Yeasu 2900 from the hamoutlet store on sale.. and need to do an install over the holidays... Im going with the same set up this guy went with.. except that I will fab my own antenna mount to be attached to the rear of the truck (that is by either using existing threaded wholes or drilling and nutserting a couple of holes....

Cable...
http://www.hamradio.com/detail.cfm?pid=H0-003639

Antenna....
http://www.hamradio.com/detail.cfm?pid=H0-000101

Im new at this but I have been reading up on it and I think this will work.....

Gotta go get my lic now...

I'll prob post something once I get all the parts.....

 

[VegasNick]

I just recently got me a Yeasu 2900 from the hamoutlet store on sale.. and need to do an install over the holidays... Im going with the same set up this guy went with.. except that I will fab my own antenna mount to be attached to the rear of the truck (that is by either using existing threaded wholes or drilling and nutserting a couple of holes....

Cable...
http://www.hamradio.com/detail.cfm?pid=H0-003639

Antenna....
http://www.hamradio.com/detail.cfm?pid=H0-000101

Im new at this but I have been reading up on it and I think this will work.....

Gotta go get my lic now...

I'll prob post something once I get all the parts.....

I mounted mine like that:

I used a Comet Mount on the rear door and it works fine. I get out anywhere I need to with it.

 

[MANUCHAO]

I made my own mount.................
It was free !!

and put my radio here

The mic will be off of the dash board.
Im using an RJ11 Female-Female panel connector and some RJ11 (6P4C) cable..
Hopefully it will work.....will see.....

 

[SteveLCetc]

Manuchao - that's kind of like my mount situation, but the mount is 30" below the roof line. I have a dual band 144/440 Yaesu 7800. I'm wondering how much it would hurt having a dead zone (? - 99 4Runner) for the bottom 30", or if I need some kind of extension, or what kind of antenna would be ideal.

Any suggestions anybody?

 

[MANUCHAO]

Steve I went with the comet SBB25 it is 57" long.
It comes above the RTT line by almost 2 feet...

 

[SteveLCetc]

Okay, I give... What is the RTT line?

 

[1911]

Manuchao - that's kind of like my mount situation, but the mount is 30" below the roof line. I have a dual band 144/440 Yaesu 7800. I'm wondering how much it would hurt having a dead zone (? - 99 4Runner) for the bottom 30", or if I need some kind of extension, or what kind of antenna would be ideal.

Any suggestions anybody?

The more antenna length you have above the roof line, the better your range, but it will still work back there as long as there is enough ground plane as your antenna needs underneath it. You don't want to lengthen the whip because the length of the whip plus any coil needs to be a resonant multiple of the frequencies that you will be transmitting on, and most mobile ham antennas are pretty close from the factory.

If you're going to mount the antenna on your bumper or spare tire mount, you will probably need a 1/2-wave antenna, since they don't require a large ground plane like 5/8 and 1/4-wave antennas do.

 

[ntsqd]

Okay, I give... What is the RTT line?

Roof Top Tent

 

[SteveLCetc]

Roof Top Tent. Duh. I was overanalyzing *that* one.

Even if I get a half wave, the metal top of the vehicle will interfere with the signal, correct? I was wondering if there is an antenna that effectively extends the height of the base (30") so I get above that interruption? I see multiple loaded antennas, but they don't seem to be clear on that point.

Thanks for the replies!

 

[canucksafari]

I've checked with two radio shops now plus the local club. They all say center of the roof or center of the hood is the best spot for an antenna to get a good ground plane. If on the hood, than make sure the tip of the antenna is unobstructed for 360 degrees. Also, hood gutter is better than a mount off the side or back of the vehicle. There should also be 2-3' of separation between any other antennas.

 

[SteveLCetc]

I've checked with two radio shops now plus the local club. They all say center of the roof or center of the hood is the best spot for an antenna to get a good ground plane. If on the hood, than make sure the tip of the antenna is unobstructed for 360 degrees. Also, hood gutter is better than a mount off the side or back of the vehicle. There should also be 2-3' of separation between any other antennas.

I agree, if a ground plane is needed. It's my understanding that a centerloaded antenna does not need a ground plane. However, I have a mount on my rear swing out tire carrier that's 30" below the roof line, so in order to get that 360 degrees I need to effectively raise the bottom of the signal producing part of the antenna so the bottom is 30" above the mount. Does that make sense?

 

[1911]

I agree, if a ground plane is needed. It's my understanding that a centerloaded antenna does not need a ground plane.

It's not so much where the coil is loaded as the wavelength multiple of the whole antenna.

However, I have a mount on my rear swing out tire carrier that's 30" below the roof line, so in order to get that 360 degrees I need to effectively raise the bottom of the signal producing part of the antenna so the bottom is 30" above the mount. Does that make sense?

The entire whip of a vertical antenna radiates signal, all the way up to the very top. As long as you have any length of it above your roof line, you will be radiating in all directions, though your radiation pattern will not be perfectly circular. The only way to do what I think you're talking about is to mount the entire antenna 30" higher.

FWIW Steve, I have my 2m antenna mounted on my swing-out tire carrier and it works fine, with less than 20" above the roof line, and the (base-loaded) coil sandwiched between the spare and the body. It's a Larsen 150 1/2-wave. I was getting out to the Abajo Mountain repeater from all over southern Utah except when right in the bottom of Dark and Mule Canyons.

Shown close-up here with the top off:

But like I said it works fine with the top on too.

 

[preacherman]

I made my own mount.................
It was free !!.

I don't believe you, make one for me prove you are not lying....

 

[MichaelArchangel]

I've checked with two radio shops now plus the local club. They all say center of the roof or center of the hood is the best spot for an antenna to get a good ground plane. If on the hood, than make sure the tip of the antenna is unobstructed for 360 degrees. Also, hood gutter is better than a mount off the side or back of the vehicle. There should also be 2-3' of separation between any other antennas.

Hello Ham gentlmen - I think you should change the word hood for roof of your Toyota FJ40 , 60, 62 models. The roof is ONE of the best locations. On the model FJ40 the back of the truck out from the rear-widow is great. Cable can be routed back inside along the top of a roll-cage.
All the best with your mod. to your rigs.
Best regards, MichaelArchangel