Radio Shack 102 to an MFJ 108?

[The Jerk]

Just an FYI, the 102 I had been using on my pickup broke at the threads.

I was starting to get a weirdness in my RX that basically sounded like a broken RX signal. SWR was still an almost flat 1.05:1 across all 40 channels, even with power.

I decided to take the antenna apart and see if I had corrosion issues. One turn of the wrench and my 102 broke off (and I was turning it in the right direction)...took almost no effort, which surprised me in the fact I would have expected the thing to have blown over while driving. The shame of it is the fact the antenna is still perfect, but I now have no way to mount it...

They don't slide the whip fully into the base, which is hollow and obviously crimped to the whip. This leaves the threads of the base (which is also brass) supporting the load placed on the antenna. I had suspected this would be an issue, didn't expect it to happen in under a year.

I have since replaced it, but I was wondering if the MFJ 108" was similar in design?

 

[W5LZ]

That sounds a little unusual, no idea why it would happen.
Those threads at the bottom is called a ferrule. On most 102" whips they are silver soldered on, not crimped. The MFJ whip uses an allen screw to hold theirs on, if I'm not mistaken. If only a short piece of that 102" broke off, you still have the option of unsoldering that ferrule, get the broke-off piece out of it, then replacing it on what's left of that 102" whip (101", or 100" whip??). Or, if you feel like it, order one of MFJ's "allen screw ferrules" to use instead. (Oh yeah, re-silver solder that thingy back on!)

One common misunderstanding about 102" whips is that they are resonant on 11 meters at that length. They are not. The reason for that is that 102" length isn't right for the center of the band to start with, and when you add on the length of the mount, that whip isn't just 102" anymore. If your mount is 4" tall, the antenna is then 106", not 102". A one inch mount = 103", 4" + 4" spring = 110". See where that's going?
Have fun.
- 'Doc

 

[The Jerk]

The whip didn't break, only the ferule (not sure that's the correct term either).

I know someone made "102 adjusters" at one point, but I haven't seen him advertise them in some time. The local shop might have something...got to talk with him next week.

Oh, and my antenna is resonate on channel 20, had a shop check it with an antenna analyzer.

 

[BOOTY MONSTER]

brass 3/8" x 24 antenna stud-H&Y Electronics

$1.03 + S&H

 

[MisterFatty]

Not sure if he is a member here, but there is a fellow who machines up a 102 whip adjuster, basically a stud mounted tube to slide the 102 in/out of for about 20 bux, may be something to consider... Sucks the antenna broke like that... If you have any interest PM me I'll see if I can get you contact info... And no, its not me, nor do I have any interest in it...

 

[The Jerk]

Not sure if he is a member here, but there is a fellow who machines up a 102 whip adjuster, basically a stud mounted tube to slide the 102 in/out of for about 20 bux, may be something to consider... Sucks the antenna broke like that... If you have any interest PM me I'll see if I can get you contact info... And no, its not me, nor do I have any interest in it...

His screen name was GunSlinger if I remember correctly, and he quit making them well over a year ago.

A local shop has those antenna studs that Booty posted, but the OE stud was also brass (and it broke!). At least it appears replaceable, and it also looks like I could slide the whip further into the stud so that it helped support the threads.

 

[W5LZ]

Common practice with a ferrule like those is to always run the whip the full length of the ferrule to support the threaded portion as you described. I don't think I've ever seen one not done that way. The ferrules I've seen have been 'hollow', didn't form a 'cup'. You could un-solder, slide up the whip to whatever point, then re-solder. Cut the whip off below the threads. Oh well, probably as many ways of doing that as there are people doing that.
- 'Doc

 

[MisterFatty]

His screen name was GunSlinger if I remember correctly, and he quit making them well over a year ago.

A local shop has those antenna studs that Booty posted, but the OE stud was also brass (and it broke!). At least it appears replaceable, and it also looks like I could slide the whip further into the stud so that it helped support the threads.

Yes thats correct but another fellow bought a bunch, and may still have one for sale...