What radio and antenna? (1 Viewer)

[Cruiserdrew]

Keith,

Jack and Dan S. are referring to this setup when we communicated at DV '07 last year:

Comet SBB-5 antenna - It has a neat fold down feature for over head obstructions and it can take a beating. This antenna sat on a simple mag mount on the middle of the roof. We were using wife's 80 on that trip so it had no permanent antenna mount of any kind.

Honestly the reason they heard me so well is because of the "ideal" antenna location in the smack center of the roof using the mag mount.

On my 80, I use a a Diamond K400SNMO with 13.5' of coax cable already attached. This is mounted on the upper hatch lip on the driver side.

My radio is an older Yaesu FT1500 55 watts max. I never tuned the whole setup during installation but Tom Ferrin from SFO checked it during CM'08 and it had pretty damn awesome SWR.

I have a Comet SBB-1 NMO for short, and I mean SHORT, range comm where overhead obstructions are everywhere.

Let me know if I can muddy the water any further!

I have to say that out of the box, the Comet antennas are extremely well tuned from the factory. Tom helped me as well and both of my Comets were isn the 1.2:1 range. The Larsens are different and are intentionally shipped long. They come with a cut chart to get you close, and then you tune by snipping 1/8 inch bits off the whip. I got a Larsen whip on my 80 down to 1.7:1 but that was the best it would do. Still, with that set up, I was talking to 450dude across the Inyo Mountains and 100 miles away.

Those hatch mounts are very nice and work very well. However, 100% of engineer types will eventually drill a hole in the roof because it's better. The rest of us don't mind compromise as much, especially since it's a small compromise! For a trail rig, I'm thinking hole in the roof. If you are interested, Jim Brantley posted up some pics of his 60. He's an engineer, and guess what? Hole in the roof.

 

[alia176]

Those hatch mounts are very nice and work very well. However, 100% of engineer types will eventually drill a hole in the roof because it's better. The rest of us don't mind compromise as much, especially since it's a small compromise! For a trail rig, I'm thinking hole in the roof. If you are interested, Jim Brantley posted up some pics of his 60. He's an engineer, and guess what? Hole in the roof.

Keith,

The NMO mount is a choice mount for roof drilling and if you look at the EMS vehicles in your line of work, I bet you'll see the same thing. The NMO mount for the roof comes with a low profile 90* coax thing that is easy to tuck above the headliner in case you're remotely considering going this route. Also, there is a nice O ring that stops any water ingress into the cab and you can do this work yourself, Mr Bigshot Fabricator You can unscrew the antenna from the mount and screw on a NMO cap that becomes practically invisible with your tall rig.

Muddying the water some more for ya...

 

[rusty_tlc]

Keith,

Jack and Dan S. are referring to this setup when we communicated at DV '07 last year:

Comet SBB-5 antenna - It has a neat fold down feature for over head obstructions and it can take a beating. This antenna sat on a simple mag mount on the middle of the roof. We were using wife's 80 on that trip so it had no permanent antenna mount of any kind.

Honestly the reason they heard me so well is because of the "ideal" antenna location in the smack center of the roof using the mag mount.
On my 80, I use a a Diamond K400SNMO with 13.5' of coax cable already attached. This is mounted on the upper hatch lip on the driver side.

My radio is an older Yaesu FT1500 55 watts max. I never tuned the whole setup during installation but Tom Ferrin from SFO checked it during CM'08 and it had pretty damn awesome SWR.

I have a Comet SBB-1 NMO for short, and I mean SHORT, range comm where overhead obstructions are everywhere.

Let me know if I can muddy the water any further!

A good ground plane, say in the middle of the roof, can greatly increase the gain of an antenna. On the Larsen web site some of their antennas are rated as 3 or 4 dB of gain with a ground plane and 0dB without.

 

[rusty_tlc]

Andy where are you getting Larsen antennas? I'm not having much luck googling vendors for them.

 

[Cruiserdrew]

Andy where are you getting Larsen antennas? I'm not having much luck googling vendors for them.

Ham Radio outlet in Oakland. I drove down there when I had some other business in the Bay Area. The guys there were very helpful and got me set with two antennas. Then I ordered some additional stuff on line and had good service, but it shipped from a HRO on the right coast so it took over a week to get.

 

[rusty_tlc]

Ham Radio outlet in Oakland. I drove down there when I had some other business in the Bay Area. The guys there were very helpful and got me set with two antennas. Then I ordered some additional stuff on line and had good service, but it shipped from a HRO on the right coast so it took over a week to get.

Thanks.
I almost never go to their site, I'll start checking them.

BTW is not totally against a hole in the 100 roof. Stay tuned for further developments.

 

[krokarthecrooked]

Well for Starters 18 Inches is all you need for the 144 MHZ band now HRO or Ham Radio Outlet is a good shop they will give you advice and and so on as far as the best antenna for the buck i do have some solid mount antenna's but you will have to drill a hole in your roof for it its small compact and will take a beating and also get you good reception and output anyway my 2 cents

Dan

 

[chicago]

OKAY...
Here's a new plan...
Tell me what I should get even if it includes drilling a hole.
I have a feeling after I get working on the air and become more familiar with the set up Ill have a much better appreciation for what you all are talking about. I cant seem to really wrap my brain around any of this without having any hands on experience.

This is all good info, but Im kinda lost.
You all know WAAAAAAY more on this, so Im gonna take your words for it.

Thanks for the help.

K

 

[rusty_tlc]

OKAY...
Here's a new plan...
Tell me what I should get even if it includes drilling a hole.
I have a feeling after I get working on the air and become more familiar with the set up Ill have a much better appreciation for what you all are talking about. I cant seem to really wrap my brain around any of this without having any hands on experience.

This is all good info, but Im kinda lost.
You all know WAAAAAAY more on this, so Im gonna take your words for it.

Thanks for the help.

K

Just go for the FT2800 with the diamond hatch mount and either the comet or the Larson antenna, the comet is sounding like the better option if you don't want to screw around. If you get into it you can always drill a hole later.
Whatever you do go with the NMO antenna mount.

 

[chicago]

OKAY.
One more question before I order...
the comet SBB-5 NMO is 38 in
the comet SBB-2 NMO is 18 in

Which one to do?

I know you said that bigger is better, but looking at the gain, the on SBB-2 is 2.15 and the gain on the SBB-5 is 3.0.
Not much (seemingly to me), but then again what do I know.

Im going with what you all recommend:
FT2800
K400NMO
and one of the comet antennas.

Thanks,
Cant wait to get geekin with you people!

K

 

[locrwln1]

OKAY.
One more question before I order...
the comet SBB-5 NMO is 38 in
the comet SBB-2 NMO is 18 in

Which one to do?

I know you said that bigger is better, but looking at the gain, the on SBB-2 is 2.15 and the gain on the SBB-5 is 3.0.
Not much (seemingly to me), but then again what do I know.

Im going with what you all recommend:
FT2800
K400NMO
and one of the comet antennas.

Thanks,
Cant wait to get geekin with you people!

K

I have the SBB-5 NMO. Mine is not mounted in the perfect spot, it's on a mount I built off of my tire carrier. The nice thing is it can take a beating and will fold over for the really tough stuff or to put into the garage.

On one of our trips, I was able to talk to RustyTLC across a mountain range over thirty miles away and he was on his HT.

I like it.

Jack

 

[rusty_tlc]

OKAY.
One more question before I order...
the comet SBB-5 NMO is 38 in
the comet SBB-2 NMO is 18 in

Which one to do?

I know you said that bigger is better, but looking at the gain, the on SBB-2 is 2.15 and the gain on the SBB-5 is 3.0.
Not much (seemingly to me), but then again what do I know.

Im going with what you all recommend:
FT2800
K400NMO
and one of the comet antennas.

Thanks,
Cant wait to get geekin with you people!

K

Decibels are a logarithmic scale, not linear. 1 extra dB of gain is a lot.

Trust me 38" will serve you better. Besides the antennas are cheap enough that you can have a shorty to swap in for trail use.

 

[chicago]

OKAY!
38 it is because of WHAT EVER it is that you said about it being straight vs curly....

K

 

[450 DUDE]

I still think for keith The SBB-1 is the best bet ( if your gonna have one antenna )

ken

 

[chicago]

I ended up HAVING to go with the comet SBB-2 NMO.
Every place that I had checked, was backordered in the NMO mount style.
Soooo my thinking was, if I need more, its easy enough to change out to the 5. At least Ill be able to operate. I guess you really cant go wrong with having TWO antennas, one longer and one shorter...
They had the SBB-5 with a standard mount, but you guyz said that the NMO is the only way to go, so thats what I stuck with.
Just so I know, WHY is the NMO mount better?
Anyway, the whole set up (radio, antenna and k400s mount) was 238.00. Not too bad I dont think?

Thanks for all the help with this!

K

 

[450 DUDE]

NMO is mo better.

The NMO mount ( you will understand when you get it ) has a nice wide base with more contact area.

Its a more secure mount / base ..

ken

 

[spressomon]

Ok...after using the center of roof magnet mount yesterday I confirmed (like I really needed additional confirmation from the electrobrainiaks of Ali, Rusty, Andy, Ken, etc.) this is the location the antenna needs to be.

So if I wanted to permanently mount an antenna mount (i.e. "drill the hole") in the hundy roof how would I go about making sure the set-up stays watertight?

And: Should I be concerned about stressing the roof due to tree branches etc?

 

[450 DUDE]

Just get a nice stand alone NMO mount designed for roof mount ( it has an O-ring )
Find your spot and drill away. Make the hole small as possible , primer the edges of the cut metal.
install with the sealant of your choice.

The structure should be strong enough , just dont put a big ole satellite on there.

ken

 

[Cruiserdrew]

I think an NMO mount requires a 3/4 hole. You will need to remove a bit of paint on the underside to establish the ground for the antenna. At least that's what I think I remember. Mounted on the roof, I'd keep the antenna short and maybe on a spring so it can bend flat along the roof.

 

[rusty_tlc]

Just get a nice stand alone NMO mount designed for roof mount ( it has an O-ring )
Find your spot and drill away. Make the hole small as possible , primer the edges of the cut metal.
install with the sealant of your choice.

The structure should be strong enough , just dont put a big ole satellite on there.

ken

Make sure you stay 1/4 wave away from the edge of the roof when selecting a location. Less is no good and more makes no difference. So stay about 20 - 24 inches from the front or back. I assume you will center the antenna side to side.

I think an NMO mount requires a 3/4 hole. You will need to remove a bit of paint on the underside to establish the ground for the antenna. At least that's what I think I remember. Mounted on the roof, I'd keep the antenna short and maybe on a spring so it can bend flat along the roof.

I'm shopping for a 3/4" Greenlee Punch. Thye make a clean hole, much nicer than a hole saw or drill.