Antenna rebuild

[Malleus]

My '94s power antenna motor decided to unlink itself from the antenna last night. I can hear the motor running when the switch (both up and down) is activated, but no antenna mast action.

Does anyone have any experience repairing/rebuilding the antenna drive unit?

 

[Skeet]

Does the mast extend and retract freely by hand?

 

[Malleus]

I haven't tried that yet. It was dark last night when drive failed, and I didn't want to troubleshoot it blindfolded.

I want to try that later today, to see if the link failed, or if it's the drive itself. I've never taken one apart; is there a section in the FSM?

 

[Skeet]

Since yours is a 94, I believe it will have a round, white cable pushing the mast. It is screwed into the mast base at one end and attached to the motor on the other. You can unscrew the chrome mounting cap, pull up the rubber washer and lift out the mast. It's helpful to have someone press the "up" button until it clicks (extends all the way) or pushes the cable all the way out (if it's broken or loose from the spool). If everything is still connected (the white cable doesn't push out completely), it's likely that the mast has a crimp somewhere and is creating too much resistance to extend and retract.

 

[Malleus]

Many thanks. I'll take a look this evening, when I can get away from the daily activities that keep me away from real work (at home with the L/C lot).

 

[Malleus]

OK, the way too long antenna repair is complete, however (there's always a however)

The solid white cable broke at the clamp inside the drum. A little filing and cussing got it wedged back in the slot.

No parts left over and I think everything went back together as originally installed, but the mast spins freely. There doesn't seem to be anything clamping it inside the guide tube. The lower bracket is in the correct position (it won't mount unless it Is), the upper end protrudes through the fender properly centered, and the rubber grommet and bezel nut are sung as I can get them.

Any thoughts?

 

[Skeet]

Did you notice a removable metal sheath between the mast and assembly?

 

[Malleus]

Yes. It was about two inches long and had a little black plastic mushroom cap on it. It went back in.

 

[Gabby1989]

Hi Everyone,

I have a 2000 Lexus LX470 and am replacing the antenna. I purchased a new antenna off ebay from a reputable seller. At first the new antenna mast appeared longer than the old antenna mast, so I removed the antenna motor assembly and retrieved the broken off section of antenna mast only to discover my new antenna mast is about 6 inches shorter than the original antenna when factoring in the broken off piece. ...

So to put it simply is it ok to install a new antenna, that has a mast that is shorter than the original antenna.... will it still work?

Found this thread and am hoping one of you might be more knowledgeable than myself on the subject, any help is appreciated and thank you in advance!

 

[Malleus]

Welcome to the forum.
Well, beyond the obvious thoughts about getting what you've paid for, yes the antenna will still work.

FYI: The length of the antenna is based on the amplitude (height) of the radio wave. The optimal length of an antenna depends on the wave it's meant to intercept. Since radio waves are sinusoidal (like ocean waves), as long as you have a mast that has a chance of getting in its way, you intercept it. The length is important because the wave is moving and you have to get in its way so you can intercept it.

Mast-style AM/FM radio antennas are called quarter wave antennas because their length is 25% of the height of the average radio wave they are meant to intercept. (the numbers on the "dial" are the measurements of the waves) The whip-style antennas that off road and military vehicles sport (the ones with those big springs at the bottom) are 1/2 or 3/4 wave antennas. A full wave antenna requires a tower. So much for the physics lesson. (my E-Mag professor would be proud)

 

[Gabby1989]

Welcome to the forum.
Well, beyond the obvious thoughts about getting what you've paid for, yes the antenna will still work.

FYI: The length of the antenna is based on the amplitude (height) of the radio wave. The optimal length of an antenna depends on the wave it's meant to intercept. Since radio waves are sinusoidal (like ocean waves), as long as you have a mast that has a chance of getting in its way, you intercept it. The length is important because the wave is moving and you have to get in its way so you can intercept it.

Mast-style AM/FM radio antennas are called quarter wave antennas because their length is 25% of the height of the average radio wave they are meant to intercept. (the numbers on the "dial" are the measurements of the waves) The whip-style antennas that off road and military vehicles sport (the ones with those big springs at the bottom) are 1/2 or 3/4 wave antennas. A full wave antenna requires a tower. So much for the physics lesson. (my E-Mag professor would be proud)

Hi Malleus, I really appreciate the information... but I'm talking about the white plastic "rope" section with teeth that feeds into the drum / power antenna assembly. The new one I purchased is not as long as the oem one by about 6 inches. (My mistake referring to it as a mast --online and on the instal paperwork they referred to it as the mast, but I realize now that doesn't make sense.)

 

[Malleus]

Ah, so. As you can see, I recently did penance for my past sins by going through this ordeal on my '94. The lift band length won't limit the antenna's usefulness, if it's only 6 inches (see my response to your post).

If you haven't installed the replacement band, be careful when disassembling the unit. The electric motor doesn't need to be removed. Pulling it off may result in several long minutes/hours of socially unacceptable language.

The OEM band is connected by a crimped connection which may be difficult to replicate; it was for me and I used to be an engineer on a manfacturing floor. In my case, the lower end snapped, just "above" the crimp. I removed the half inch still clamped and stuck the "new" end in its place. I resorted to grinding the pins holding strap inside the bowl until I could remove the strap. I held the band in place by creating a new clamp, without the strap, by crimping the bowl with a pair of vise grips. This will be obvious when you look at the bowl.

After going through this, and comparing the '94 to my '95, I have decided to replace the '94s antenna with a '95-'97 vintage. The toothed band is a much better design. You might try CruiserParts.net Landcruiser Parts , or local salvage yard, for a replacement. A working used unit is still worth the money and is considerably cheaper than new OEM. Note that the Lexus LX450 antennas are different; their stereos are set up for "auto up when on". You may still be able to use them; I haven't looked into it, but it does give you more search options.

HTH

 

[Gabby1989]

Ah, so. As you can see, I recently did penance for my past sins by going through this ordeal on my '94. The lift band length won't limit the antenna's usefulness, if it's only 6 inches (see my response to your post).

After going through this, and comparing the '94 to my '95, I have decided to replace the '94s antenna with a '95-'97 vintage. The toothed band is a much better design. You might try CruiserParts.net Landcruiser Parts , or local salvage yard, for a replacement. A working used unit is still worth the money and is considerably cheaper than new OEM. Note that the Lexus LX450 antennas are different; their stereos are set up for "auto up when on". You may still be able to use them; I haven't looked into it, but it does give you more search options.

HTH

That makes me feel better, another member on a similar thread had the same conclusion that the shorter lift band shouldn't negatively affect it. It's on a 2000 LX470, so the antenna was only $15 shipped thankfully. Thanks Again, I think I'm going to try for reassembly today... fingers crossed.

 

[Malleus]

Put a beer back; you'll be glad you did. Good luck.

By the way, you may get more applicable advice in the 100 series forum, but we're all glad to help! (nevermind; I just saw your other post!)