predator shaft length

[herbman]

I am planning on moving to a permanent mount on my jeep cherokee using a predator and I am wondering how big the TX/RX difference is going from say the 9" to the 27" shaft?

I want to mount it coming off the back where the trunk closes or on the hood opposite the regular antenna and I want the predator to come up just as high or only a little higher than the vehicle thus eliminating problems when going into parking garages.

Also I understand I'll lose range by not having it on the roof, but is this a big loss?

[blackjack]

i recommend getting a shaft length were the coils are above the roof line. mesure it out and then go from there but make sure you get the coils above the roof line. its pretty point less to run one of these antennas unless you have the coil above the roof. shorth shafts were made for the truckers because of clearance issues. so if i am correct you may need a 27 or a 17 inch shaft. just my 2 cents

[Phaze91460]

And what about when your mounting above the roof line ?

[blackjack]

if you mount it directly on the roof go with a shorter shaft. like thumper said there is no differance in the size of teh shaft . its just to get the coil above the roof line[/quote]

[jessejamesdallas]

Main difference's between the shaft leigths on top of your roof, is not nessesarly going to have that much difference in RX/TX...

Mostly the difference will be on how broad banded the antenna will be.

The shorted shaft's will not tune as low as the taller shaft's. But were only talking about the difference between a average of 1.1 to 1.2 swr useing the shorter shaft, vs. 1.0 to 1.1 useing a longer shaft...

For instance. On my Suburban. I have the 27" shaft. Tunes out @ 1.0 across all 40 channels. Useing the 17" shaft, it will get 1.0 on around 5 or 6 channels, and the rest would be 1.1....Useing the 9" shaft I was getting 1.1 on most of the middle channels, and 1.2 on channels closer to channel 1, and channel 40...

One quick note...All vehicle's are a little different when installing antennas. So your results could be a little different. Due to ground plane, and location of your mount....

In most case's, the higher you get the Coil's of the antenna, over the roof line. The better your swr will be... However. This will also make for a shorter stinger. And you'll have a taller target for tree limbs to hit!

[RabidRobert]

And as I understand it, short shafts have longer wips & vica versa, so overall length of antnna stays the same?

[Phaze91460]

10-4 hittin the trees ! I have to go to the airport in a little while and will have to park at the parking deck, I barely clear in there with ladders, Aint gonna with any antenna.

Mr RA made a comment ( which makes sence ) about not running a quick dissconnect. I think that there are going to be many times I will have to remove an antenna, Any options ?

[Rex_foxhound]

well with my wilson 5000 I have to take it off when I go into extremely low clearance areas. The whip can flex a good distance, but a predator has a shaft that doesn't flex. I would get a tri-magnet mount if I needed to take it off. :06-01smi:

[RabidRobert]

Doesnt the 10K unsrcew at the base mount, like the wilson load coils?

[herbman]

this is why i want to mount the predator in such a way that I won't have to take it off ever

[blackjack]

the predator does unscrew at the base. i unscrew mine all the time win i go into parking garges or if i go to burger king or something. doesn't bother me taking it down. all around good antenna. i would recommen it to anyone. you get some strange looks to especially if you are running duals. i was listening in on ch19 the other day while running my duals and this trucker said why in the world would someone need so many antennas. i just laughed. then i keyed up and aske dhim what did he say cause i had the maul down lmao

[Rex_foxhound]

Speaking of duals, I noticed many pictures of suburbans with dual 10K's.

I know trucks have them because of the trailer and they can get them far enough apart so they don't interfere with one another, but I was wondering why you would put 2 on top of a burban? Seems like they would interfere but I may be wrong.

Probably a simple answer but I just don't know what it is.

[Phaze91460]

this is why i want to mount the predator in such a way that I won't have to take it off ever

Would be nice, but I live in a world where I have to go into tree covered neiborhoods, bank windows, low covered bridges, driveways with gates and arches, parking decks for downtown condos with no other parking locations, etc. So I have to look at all the options and make a choice, sometimes it is not the best performance choice but needed to cover as many factors as possible.

[RabidRobert]

you get some strange looks to especially if you are running duals.

I saw a newer model VW Beetle the other day that had dual 10Ks on the roof, one on each side above the doors!!!! Guess what color? GREEN!!! Looked like a Martian! I dam near had to pull over I was laughing so hard!
:4-ufo:

[jessejamesdallas]

Speaking of duals, I noticed many pictures of suburbans with dual 10K's.

I know trucks have them because of the trailer and they can get them far enough apart so they don't interfere with one another, but I was wondering why you would put 2 on top of a burban? Seems like they would interfere but I may be wrong.

Probably a simple answer but I just don't know what it is.

Sence Suburbans have such a long roof line, that makes them perfect for this type of set-up...Antennas have to be 6' apart to work right. Now there are two ways of working this kind of set-up.

1'st, would be running 2-Hot's...This is both antennas hooked up to the same coax, generaly the coax from the radio,(or amp) would go to the back antenna first, then to the front. Running the antennas this way, gives a more directional signal effect... (forward's and backward)


Other op. Would be to run just one of the antennas hot, and the other as a reflect antenna. Generaly the front antenna would be the only one hooked to radio, back antenna act's as a reflect antenna, makeing the signel more directional toward's the front, less out the back...

[Rex_foxhound]

All right. Thanks jessejamesdallas! That answered it for me. :Peace!:

[jessejamesdallas]

10-4 hittin the trees ! I have to go to the airport in a little while and will have to park at the parking deck, I barely clear in there with ladders, Aint gonna with any antenna.

Mr RA made a comment ( which makes sence ) about not running a quick dissconnect. I think that there are going to be many times I will have to remove an antenna, Any options ?

One option is to have a mount that will lay your antenna down, and the raise it back up, later! This is what a friend of mine came up with...and are getting very popular around Dallas...


His Email and phone number are on the bottom of the page...He go's by "Radar"...Stay's buissy building these mount's, so may take a day or two for him to get back to you..