Mechanical Help with broken Centre-Load CB antenna

[CanRadioFan]

Hoping this is the right sub for this post.....

I have a classic, old-school, stainless-steel CB/AM/FM antenna with a 'centre-load'. Sadly the top section of the antenna broke off right where it enters at the upper part of the center-load leaving a Stainless steel stub inside. The upper section of the antenna is locked into the centre load with a set screw which I have removed but I can't get the stub to budge - my guess is it's ben slightly. Do these center-loads - which seems to be made of plastic with some kind of aluminum alloy end caps - come apart? Wondering if I could push the stub out from the inside.

Hoping someone else has experienced this problem and has figured out a way to extract the broken off stub.

 

[Trucker700]

Maybe, try either a very small EZ out or drill bit. Go slow and don't back the bit out. Then try and pull it out. A bit of WD40 or machine oil might also help.
James

 

[prcguy]

The stainless whip is much harder than the part with the set screw which is usually brass. It takes a good machine shop to accurately drill out a whip and not damage the area around it. The part with the set screw may unscrew from the larger section below it, try that and maybe it has a through hole for the whip where you can bang it out with a nail or something similar. Or try putting some Liquid Wrench in the set screw hole and bang on the top area around the whip to see if the broken whip will start to come out. Liquid Wrench and mechanical shock can loosen lots of stuff.

 

[dave3825]

Patience and the right tools. If the set screw is out, a little oil of wintergreen (from a drug store) or acetone and tranny fluid (50/50 mix) works wonders on rusted or corroded parts. There could be some corrosion in there or the whip could be slightly bent.

If it were mine, I would put oil in the set screw hole and at the top where the whip is broken off and let it sit. After a few hours, I would try turning it over and start tapping the top on something solid, like a bench vice, in hopes the whip starts to move. You only need it to move like 1/8 or 3/16 of an inch and then pull it out with pliers.

I have an old Rat Shack mag scanner antenna with a stripped set screw I have been soaking for a while. I can get a slotted jewelers screwdriver to fit in the allen and it's almost freed up.

 

[wtp]

if it is in the center (center load) is there a set screw on the bottom of the load ?

 

[RFI-EMI-GUY]

I don't think you can get that apart from the plastic without damage. Try some moderate heat along with a solvent. Use a hair dryer set high to try and expand the outer post slightly, while the rod remains cool. More heat might be better, but again the plastic might get damaged. So you might repeat adding solvent and reheating. If you have a small probe or punch you might be able to push the rod out via the setscrew hole. All you need is enough to grip.

 

[CanRadioFan]

I don't think you can get that apart from the plastic without damage. Try some moderate heat along with a solvent. Use a hair dryer set high to try and expand the outer post slightly, while the rod remains cool. More heat might be better, but again the plastic might get damaged. So you might repeat adding solvent and reheating. If you have a small probe or punch you might be able to push the rod out via the setscrew hole. All you need is enough to grip.

Thanks for the suggestions, fellas.

I have the set screw out; I was hoping I could get at the bottom of the stub through the hole but no luck. I've tried some heat cycles and various penetrating fluids, no luck yet. I'm not steady enough to drill a small hole in the stub (how difficult is it to drill stainless?) but maybe a machinist could.

 

[prcguy]

Thanks for the suggestions, fellas.

I have the set screw out; I was hoping I could get at the bottom of the stub through the hole but no luck. I've tried some heat cycles and various penetrating fluids, no luck yet. I'm not steady enough to drill a small hole in the stub (how difficult is it to drill stainless?) but maybe a machinist could.

Have you tried to unscrew the piece with the set screw from the coil assembly? Drilling any kind of stainless steel is a b*tch.

 

[CanRadioFan]

Have you tried to unscrew the piece with the set screw from the coil assembly? Drilling any kind of stainless steel is a b*tch.

Yes, I can partially disassemble the centre-load, but the internals seem to be cemented to the alloy cap (in which the broken stub resides). I don't think it's screwed, but I'll take another look.

 

[krokus]

The best penetrating oil I've seen is PB from Blastr. Spray cans are the most common, but they also have pump spray with refills. The refill could supply a syringe, eye dropper, or pipette.

 

[RFI-EMI-GUY]

Get an automatic center punch like this one *. Put it in the hole for the set screw at a ~45 degree angle toward pushing the rod out. Press the punch until it fires. Repeat as necessary.

* one that has small punch diameter.

 

[slowmover]

The best penetrating oil I've seen is PB from Blastr. Spray cans are the most common, but they also have pump spray with refills. The refill could supply a syringe, eye dropper, or pipette.

50/50 Acetone/ATF is much superior.
Even over KROIL.

The acetone will flash off fairly soon. Only make as necessary.

And be careful with POL on antennas. SIRIO warns against such use, in general.

.

 

[RFI-EMI-GUY]

50/50 Acetone/ATF is much superior.
Even over KROIL.

The acetone will flash off fairly soon. Only make as necessary.

And be careful with POL on antennas. SIRIO warns against such use, in general.

.

Whats POL?

 

[prcguy]

Get an automatic center punch like this one *. Put it in the hole for the set screw at a ~45 degree angle toward pushing the rod out. Press the punch until it fires. Repeat as necessary.

* one that has small punch diameter.

This can work for about 1/16 inch, then the divot made by the center punch will get stuck when it hits the edge of the set screw hole. Now the broken whip will never come out.

 

[slowmover]

Whats POL?

Sorry. Petroleum-Oil-Lubricants

 

[slowmover]

This can work for about 1/16 inch, then the divot made by the center punch will get stuck when it hits the edge of the set screw hole. Now the broken whip will never come out.

A story accompanies this? Do you still keep it in the garage rafters?

 

[N0ZQR]

Is the antenna worth the work?

 

[RFI-EMI-GUY]

Is the antenna worth the work?

That's the question everyone wanted to ask.