Antenna repair

[KsM715]

Does anyone have any ideas on how to remove this piece so I can re-assemble this antenna? I bought it for display purpose only so I dont care that it wont ever work again but I would still like it to stay together when tied down.

It looks like the previous owner had trouble unscrewing the two sections and the inner part of the lower half stayed on the upper half. It has marks on it from where it looks like a pair of vice grips were used on it but the small threaded area at the very bottom ( the top in the pic) looks like it needs to come off first so I can get the shiny part off. Its soaking in pb blaster as we speak.

Edit: The threads where the shiny lower half meet that brass looking piece at the top do not meet. The threads on the shiny part stop about an 1/8 of an inch before the end. If anyone can get a pic of a working antenna end I would apreciate it.


Thanks
Jeff


ps sorry for the crappy pic. Its time for a new camera.

 

[mistaken1]

Assuming the one on the right is the upper half that is normal. Kind of a shallow corrugated thread stem on the upper half that screws into the lower half with a little bit of overlap on fiberglass shells.

 

[mistaken1]

Some pictures......

 

[KsM715]

Thanks,

I guess I need to just keep soaking it and see if it will loosen up. The problem looks like its so thin that when you clamp down on it with plyers or vice grips you end up grabbing the inner part to. Might have to cut it off with a dremel tool. But then I need to figure out how to reassemble the antenna and keep it together.

 

[mistaken1]

What about cleaning the lower part (degreasing the recess) and cleaning the outside of the insert stuck to the upper part and using epoxy to attach the insert to the lower part of the antenna?

I am assuming that the insert attached to the upper part will screw down into the lower part.

That may let you unscrew the two halves or at least hold it together to allow it to be bent and tied down.

There really is not much overlap on the fiberglass part of the upper and lower (I would like to see 3"- 4" of overlap rather than the 3/4" of so that exists on both my antennas).

 

[papakb]

mistaken1,


The AT1729 antennas are notorious for doing this if they aren't taken care of. These pieces are copper plated steel and when left screwed together they do exactly what you see they've done. The same thing happens to the newer Singars version of this antenna.


They really aren't repairable at this point and as common as they are they're not really worth the effort to repair them. You can typically find good used sections fpr $5 to $15 each. I have used a .22 bore brush on a battery drill to clean them.


A word of advice, when you assembly them put some silicon lube on the threads beforehand to keep this from happening. Never leave the antennas together when stowing and if you want to leave the lower section on the matching unit, buy some small vinyl caps to keep the water out of the top socket.


The again, if all you want is a display antenna then just epoxy them together and be done with it.


Kurt
KG6KMJ

 

[mistaken1]

I have one spare antenna, the one in the pictures. I was going to clean it some more but have not worked on it in weeks. The one on my truck was new in the box and I did put silicone grease on it. I need to put silicone on the spare one to keep the halves from seizing before I get around to cleaning it again.

The one on the truck I am using on six meters but I think I can lower the SWR if do something to change the relay state in the MX6707 base. Something other than power it. Next time I have it apart I will see if I can possibly wedge some rubber in to simulate the powered condition. If not I may have to rig a relay on the 6-meter to allow it to send 24V to the base.

I am KD0KMJ

 

[OPCOM]

JBweld..

For 6M, you ought to be able to turn the knob to select the best match. It still might not be very good.

 

[mistaken1]

2:1 right now. As I read the wiring diagram the closest match to 6M is when the relay is energized. I am hoping that will get me below 2:1.