Motorola Antenna mount question

[n0nhp]

That would be great. But like I said at this point I am tapped in the way of funds to support this obsession...I mean Hobie of mine :lol:.

I am not sure mounting the stubby whip would be good anywhere but the roof, less chance of people walking by and snapping it off I guess. But like I said I am not sure I want to drill a hole in the roof either, mostly becuase I have a feeling it would leak.

Thanks for the ideas all!

Out of the hundreds (or more) I installed over the years, the only leaks I had were on the cement mixer trucks. They have a habit of using Muriatic acid to clean the trucks up. Brass and acid don't react very well to one another.

The NMO base has a rubber seal and most of the antennas have a second seal around the base of the antenna. If you need to remove the antenna to wash the vehicle, invest in a weather cap to screw on the base before you run it through the car wash. This is not so much for water proofing as it is to keep the silver contact from getting coroded or worse yet getting the spray wax on it.

I still have the $75.00 hole saw but thankfully it very rarely comes out of the tool kit anymore. It is mostly used on my own cars.

The other objection to drilling holes in roofs was "resale value".

Talking to a used car dealer (happened to be a ham), a hole in the roof would drop the value a bit but if it had the $1.50 vinyl hole plug in it, most customers never even noticed it. If they did a can of touchup paint and a few seconds would hide it to the point of near invisibility.

/edit: from the deparment of redundant redundancies

 

[cstockmyer]

Out of the hundreds (or more) I installed over the years, the only leaks I had were on the cement mixer trucks. They have a habit of using Muriatic acid to clean the trucks up. Brass and acid don't react very well to one another.

The NMO base has a rubber seal and most of the antennas have a second seal around the base of the antenna. If you need to remove the antenna to wash the vehicle, invest in a weather cap to screw on the base before you run it through the car wash. This is not so much for water proofing as it is to keep the silver contact from getting coroded or worse yet getting the spray wax on it.

I still have the $75.00 hole saw but thankfully it very rarely comes out of the tool kit anymore. It is mostly used on my own cars.

The other objection to drilling holes in roofs was "resale value".

Talking to a used car dealer (happened to be a ham), a hole in the roof would drop the value a bit but if it had the $1.50 vinyl hole plug in it, most customers never even noticed it. If they did a can of touchup paint and a few seconds would hide it to the point of near invisibility.

/edit: from the deparment of redundant redundancies

Good to know thanks!

 

[cstockmyer]

My antenna's

I went and got them today. The large one only does I think 800 to 860, witch might work for some I think. The other small and stubby one does the 800 band the best, according to the sales guy. Sorry about the pic, I suck at taking pictures.


The picture of the base sucks, I could not find a program to get into focus the threads, and keep it under the limit of what I could post here. It gave me a headache just looking at it!

 

[mpg0515]

The one on the left should be the better one.... That is a 3Db gain antenna versus the unity gain antenna on the right side. Also they can both be cut/adjusted to get you to whatever freq you desire. But they both look like they will do just fine in the 800Mhz band, just judging by the size mostly. For the unity gain antenna, about 3" should do the trick.

 

[cstockmyer]

So they are both good for the 800 band? I was under the impression that the big antenna was cut for the 800 to 860 band. I ordered that at first then realized that DPD and APD both have frequencies over 860. The small one as you see it was 4.50$ so I'm not out to much if the bigger one ends up fitting my needs. Now I just have to wait to get the mounts, either that or win power ball or lotto.

 

[mpg0515]

So they are both good for the 800 band? I was under the impression that the big antenna was cut for the 800 to 860 band. I ordered that at first then realized that DPD and APD both have frequencies over 860. The small one as you see it was 4.50$ so I'm not out to much if the bigger one ends up fitting my needs. Now I just have to wait to get the mounts, either that or win power ball or lotto.

Correct, they are both for the 800Mhz band. The antenna with the coil (on the left) is the better antenna of the two for both transmitting and receiving. However it would need slight tuning if you were to use it to transmit above 860Mhz, not much though. I use the same antenna for the DTRS and it works great! I am not transmitting though so there is no need to adjust it for that and again the top end of the antenna (866Mhz) is not very far off of your target of DPD or APD. If I needed to transmit, I would need to cut the antenna a little bit (like a half an inch at a time) to get where I needed. At the 800Mhz frequency, just a little bit of adjustment is needed to get to where you need it. Also, you are not out any money, like I said they are both for 800Mhz, one is just going to "work" better. One is a 1/2 wave (3Db gain), the one with the coil, and the other is a 1/4 (unity or no gain). You may not notice any difference being in the metro area but for me it makes a huge difference being up here in FTC.

 

[cstockmyer]

Thanks!

Correct, they are both for the 800Mhz band. The antenna with the coil (on the left) is the better antenna of the two for both transmitting and receiving. However it would need slight tuning if you were to use it to transmit above 860Mhz, not much though. I use the same antenna for the DTRS and it works great! I am not transmitting though so there is no need to adjust it for that and again the top end of the antenna (866Mhz) is not very far off of your target of DPD or APD. If I needed to transmit, I would need to cut the antenna a little bit (like a half an inch at a time) to get where I needed. At the 800Mhz frequency, just a little bit of adjustment is needed to get to where you need it. Also, you are not out any money, like I said they are both for 800Mhz, one is just going to "work" better. One is a 1/2 wave (3Db gain), the one with the coil, and the other is a 1/4 (unity or no gain). You may not notice any difference being in the metro area but for me it makes a huge difference being up here in FTC.

Thanks. At the very leased I guess I can try them both once I get a mount to mount it on, see witch one works best and where right?

How much does it cost to get a trunk mount installed and the cable run? I drive a ford exploder so it would have to go on the hood, does that make a difference in the price?

 

[RISC777]

Thanks. At the very leased I guess I can try them both once I get a mount to mount it on, see witch one works best and where right?

How much does it cost to get a trunk mount installed and the cable run? I drive a ford exploder so it would have to go on the hood, does that make a difference in the price?

Mounts like that you can get some generic type multi-use brackets, and there are also vehicle specific bracket mounts. To look for is that type mount that at least has the base and cable already terminated to that base. Otherwise, you're looking for the base, having to terminate cable to it, and terminating the connector for the scanner at the other end.

There are members here local that have done permanent (in the body metal mounts) that can provide advice or actually help with the install maybe. It's not going to be that hard. I think you could do it yourself, but I know the feeling of going at something for the first time.

Last comment, the longer antenna will also work for you, most likely, in receiving UHF and VHF. How well in those ranges, hard to say. But if your focus is on the 800 public safety range, you're good to go. And, you can always get other antennas for VHF or/and UHF that will attach to the same base/mount. That's why the threaded "nut" of the base has those two flat spots, for a wrench. And being careful with it you can take it off, put it on, put a different one on with no damage to the antenna(s).

'Doug

 

[cstockmyer]

Mounts like that you can get some generic type multi-use brackets, and there are also vehicle specific bracket mounts. To look for is that type mount that at least has the base and cable already terminated to that base. Otherwise, you're looking for the base, having to terminate cable to it, and terminating the connector for the scanner at the other end.

There are members here local that have done permanent (in the body metal mounts) that can provide advice or actually help with the install maybe. It's not going to be that hard. I think you could do it yourself, but I know the feeling of going at something for the first time.

Last comment, the longer antenna will also work for you, most likely, in receiving UHF and VHF. How well in those ranges, hard to say. But if your focus is on the 800 public safety range, you're good to go. And, you can always get other antennas for VHF or/and UHF that will attach to the same base/mount. That's why the threaded "nut" of the base has those two flat spots, for a wrench. And being careful with it you can take it off, put it on, put a different one on with no damage to the antenna(s).

'Doug

It's good to know I have the right antenna, I am just not sure about doing it myself. I wish I could say I am that technical, to drill holes in fire walls and run cord lol. But maybe your right I could try..Thanks!

 

[mpg0515]

Here is my setup with trunk lip mounts

3DB 800Mhz antenna and a 1/4 wave VHF antenna (about 19" tall)

These work ok, but I think that a more permanent install on the trunk is in the near future. Just to give you an idea of what you can do, I guess if you have a truck though this might be kind of hard.

 

[cstockmyer]

Yeah I would have to do something on either the hood or the roof, I am leaning more towards the hood though.

 

[cstockmyer]

I am confused

Will NMO trunk mounts work on a hood? I went on eBay and searched for NMO trunk mounts, they have a few all under 15 bucks for the mount and the cord and all. What do you call the mount you use on a hood? It just seems to me if I where to mount a trunk mount on a hood, I'd have to take the antenna off in order to get under the hood. Am I wrong?

 

[RISC777]

Will NMO trunk mounts work on a hood? I went on eBay and searched for NMO trunk mounts, they have a few all under 15 bucks for the mount and the cord and all. What do you call the mount you use on a hood? It just seems to me if I where to mount a trunk mount on a hood, I'd have to take the antenna off in order to get under the hood. Am I wrong?

A mount on a hood - (you don't want to permanent mount in the hood obviously since it would be in your way of seeing the road, etc. ~grin~) so a "lip mount" on the edge of the hood would be best. On the 'side' of the hood you're going to have "half" of a ground plane - the metal of the hood. One thought would be, say, on the passenger side put a lip mount about 5 inches in from the side so that the hood's metal and the dash provides a better ground plane. Though at the same time you could do a permanent, hole through the hood, mount, though dealing with the bottom side of the hood as far as noise and heat protection materials (thick mount bases are made and available). Put the permanent mount 4 to 5 inches in from the side and the same from the back edge of the hood towards the front.

If you had found an antenna designed to work without a ground plane you could mount in anywhere. But, a lip mount means no holes in the body, no screws to attach a bracket, etc.

And going or getting through the firewall is easier than you might think.

`Doug

 

[cstockmyer]

A mount on a hood - (you don't want to permanent mount in the hood obviously since it would be in your way of seeing the road, etc. ~grin~) so a "lip mount" on the edge of the hood would be best. On the 'side' of the hood you're going to have "half" of a ground plane - the metal of the hood. One thought would be, say, on the passenger side put a lip mount about 5 inches in from the side so that the hood's metal and the dash provides a better ground plane. Though at the same time you could do a permanent, hole through the hood, mount, though dealing with the bottom side of the hood as far as noise and heat protection materials (thick mount bases are made and available). Put the permanent mount 4 to 5 inches in from the side and the same from the back edge of the hood towards the front.

If you had found an antenna designed to work without a ground plane you could mount in anywhere. But, a lip mount means no holes in the body, no screws to attach a bracket, etc.

And going or getting through the firewall is easier than you might think.

`Doug

If I do this on the passenger side, won't my AM/FM normal antenna effect it??

 

[RISC777]

Dunno, Charles. Sent an email off to an engineer with that question. (Since no expert has answered it here yet. ~grin~ ) I'll stick a mag mount next to my radio antenna on my POV and see what I see. I don't think either will effect either. Besides, they make those in-line adapters to have your scanner be able to use the AM/FM antenna. [Should I start ducking now for flames/flaming?]

 

[cstockmyer]

I am still confused on the mounts my self. I know when I got an antenna from radio shack it said not to put it near my radio antenna. So that means I'd have to do it on the driver side right?

 

[RISC777]

Was it a receive only antenna, or a CB trnsmit maybe? The transmitting would definitely be a reason not to. And if you go the lip mount route, is the driver side not to your liking?

 

[mpg0515]

I am still confused on the mounts my self. I know when I got an antenna from radio shack it said not to put it near my radio antenna. So that means I'd have to do it on the driver side right?

Ok, look at my setup again and you will see that the antennas are very close together, about 8-9" apart. This would be a problem except the bands (VHF and 800Mhz) are so far apart that it will not affect anything. I do however not operate my Pro-96 while transmitting on VHF. The power of my 2M rig will most likey damage the front end of the Pro-96 if I am monitoring while talking. If you are going to have several radios operating at once, you will want to have the antennas placed farther apart. But with that in mind, take a look at a CSP car, their antennas are almost mounted exactly like mine. Their cars have, of course, DTRS and VHF (in most of them). So really you have nothing to worry about with your AM/FM radio....

Also don't forget that their are several magetic mount NMO styles that you can put those two antennas that you bought on without drilling or antything like that. They are about the same price, $15 or so. There are so many options to you, you just have to decide if you want the install permanent or not....

 

[RISC777]

Yeah, I walked the 396 by a garage radio and my car's radio. Neither interfered with any of them.

 

[datainmotion]

My fender mounts

FWIW Here are the two antennas I have mounted on my fenders.