How take apart base antenna

[AB6CJ]

I just got a used (very old) base antenna, Diamond X510NA, 2m/70cm dual band. The actual antenna part is fiberglass but the bottom 1.5' is aluminum tubing. I need to remove the aluminum tubing in order to get to the place where I can attach my coax cable. But it's too corroded to remove. I've tried: strap clamps, liquid wrench with tapping (5 times & waiting 2 days), heavy tapping with rubble mallet, heat gun (with tapping & strap clamps). I can't get it to budge a all. I've removed the screw that holds the parts together. Also removed the 3 radials. Any other ideas as to how to get it off?

Below is a newer model, but I assume the construction is similar:
https://www.diamondantenna.net/pdfdocs/X510instructions.pdf

 

[prcguy]

This is a common problem with Diamond, Comet and others that use a super fine thread on a pipe extension over the connector. I recently had a Comet GP-9 commercial version with a frozen bottom pipe and ended up using a pipe cutter and removing it right above the threads. The aluminum mounting pipe now ends just past where the connector sticks out and it allows you complete access to the connector to wrap with tape for weather proofing.

I just got a used (very old) base antenna, Diamond X510NA, 2m/70cm dual band. The actual antenna part is fiberglass but the bottom 1.5' is aluminum tubing. I need to remove the aluminum tubing in order to get to the place where I can attach my coax cable. But it's too corroded to remove. I've tried: strap clamps, liquid wrench with tapping (5 times & waiting 2 days), heavy tapping with rubble mallet, heat gun (with tapping & strap clamps). I can't get it to budge a all. I've removed the screw that holds the parts together. Also removed the 3 radials. Any other ideas as to how to get it off?

Below is a newer model, but I assume the construction is similar:
https://www.diamondantenna.net/pdfdocs/X510instructions.pdf

 

[AB6CJ]

Wait, it's threaded on? The directions don't mention anything so I thought it was just slipped on. I'll try un-screwing it. If that doesn't work, not sure what you're saying about cutting it off. Where did you cut it? You said "above the threads", I'm not sure where the threads are. In my case, it seems the threads would be above the connector (when the antenna is oriented in the operating position). Thus I would cut below the threads? Then I could get to the connector. But how would I mount the antenna since I would have just cut the mounting pipe off.

 

[ka3aaa]

penetrating oil and soak a few days

 

[prcguy]

I don't know if your specific Diamond model is threaded but I've not seen a slip on extension that goes over the connector area.

I measured from the bottom end of the mounting pipe to the flat bottom of the antenna up inside the pipe, and the threaded area on my Comet was just past the flat bottom of the antenna. I set the pipe cutter as close as I could to the flat bottom of the antenna where the connector mounts and cut there. Here is a pic of what I ended up with. The end of my antenna is beat up pretty bad from pipe wrenches trying to unscrew it and would be nice to have a little more pipe go past the base of the antenna, but it still works fine.

Wait, it's threaded on? The directions don't mention anything so I thought it was just slipped on. I'll try un-screwing it. If that doesn't work, not sure what you're saying about cutting it off. Where did you cut it? You said "above the threads", I'm not sure where the threads are. In my case, it seems the threads would be above the connector (when the antenna is oriented in the operating position). Thus I would cut below the threads? Then I could get to the connector. But how would I mount the antenna since I would have just cut the mounting pipe off.

 

[AK9R]

This is a common problem with Diamond, Comet and others that use a super fine thread on a pipe extension over the connector.

None of the Diamonds I've owned or been around were threaded in this manner.

The Diamond X series antennas that I've seen have a base, the part that holds the coax connector, the radials, and the fiberglass tube (radome), which is a casting, probably aluminum or zinc that has been chrome or nickel plated. The tube is usually aluminum and slips onto the base. A hex-head machine screw, I'd guess it's an M6 since it has a 10mm head, goes horizontally through the tube into the base. There are multiple joints with dissimilar metals in all of this.

The photo you posted doesn't look like any Diamond antenna in the X series that I've seen.

 

[AB6CJ]

penetrating oil and soak a few days

I was using Liquid Wrench, then switched to WD-40, since then I could spray. It's hard to get to the corroded area. I tried the junction of the top of the mounting pipe/bottom of the fiberglass, but I don't think much can get in there. Then tired the bottom of the mounting pipe & try to spray all the way up to the top. Then tired into the hole where the set screw goes into & hope that seeps in. Any other ideas? I'll keep trying for a few days.

 

[AB6CJ]

None of the Diamonds I've owned or been around were threaded in this manner.

Ok, maybe it's not threaded. I'm still trying with the WD-40.

 

[Ubbe]

WD40 and equal stuff just goes on top of things and doesn't go between tighly pressed surfaces like threads and metal to metal. Only thing that works are other types of oil like Omicron/Omega 636 that includes pimento oil from Jamaica. It cost more than double up of a can of WD40 but are one of few things that actually goes into the threads and loosen it, as well as corroded aluminum.

WD40, CRC5-56 and equal stuff are for lubcrication of already exposed surfaces that can be used when you put things together to prevent them from corroding.

I have a X510 and the bottom tube are just slipped on without any threads.

/Ubbe

 

[AB6CJ]

I have a X510 and the bottom tube are just slipped on without any threads. /Ubbe

Ok, I'll go with slip on (not threaded). In that case, would WD-40 work, as it doesn't have to get into the threads?

 

[k4fv]

I have a Diamond X510NA on the ground. Here's what the threaded base looks like with the N connector exposed. The screw on cover is shown on the right hand side of the u-bolt with threads facing outwards. I would try PB Blaster or penetrating oil. It unscrews counter clockwise.

 

[AB6CJ]

Well, that's confusing. You show the "screw on cover", which looks about 1-2" in length. Mine doesn't have anything like that, just the 1.5' pole. Plus, your U-bolt is above the connector, which means that part must be metal. For mine, everything above the connector is fiberglass, thus my U-bolts have to be below the connector, since that part is aluminum. So looks like we have different models.

 

[prcguy]

That Diamond X510NA is roughly what my Comet antennas look like with the threaded connector protector. Hey, that rhymes! I've had other models of antennas that had a single bolt about 1/4" dia that held the mounting pipe on and that's a completely different animal that should not corrode together.

Well, that's confusing. You show the "screw on cover", which looks about 1-2" in length. Mine doesn't have anything like that, just the 1.5' pole. Plus, your U-bolt is above the connector, which means that part must be metal. For mine, everything above the connector is fiberglass, thus my U-bolts have to be below the connector, since that part is aluminum. So looks like we have different models.

 

[AK9R]

I think the various posters in this thread are talking about different antennas. Some of the Diamond antennas are heavier-duty models and it wouldn't surprise me that they are constructed differently at the base. I also think that the design may have changed over the years.

The Diamonds with the slip-on bottom tube look very similar to the antenna shown in these assembly instructions: https://www.diamondantenna.net/pdfdocs/X510instructions.pdf

The assembly instructions for the X700HA and X700HNA show a different design that appears to have a screw-on tube at the base of the antenna covering the coax connector: https://www.diamondantenna.net/pdfdocs/X700HNA.pdf

Ubbe mentioned various penetrants and lubricants including CRC 5-56. I have a machinist friend who speaks very highly of CRC Knock-er-Loose: Knock'er Loose® Penetrating Solvent, 13 Wt Oz

 

[Ubbe]

In that case, would WD-40 work, as it doesn't have to get into the threads?

Probably not. If it have stuck solid it probably are no space for normal lubricant to reach. Use one of the special penetrating oils. I use it for everything and works wonders for bicycle chains, much better than special chain oil.

/Ubbe

 

[AB6CJ]

Probably not. /Ubbe

I can't find 1 can of CRC5-56 on Amazon.

 

[k3hal]

I can't find 1 can of CRC5-56 on Amazon.

as a retired maintainence mechanic/machinist for the last 46 years, the ONLY penetrating oil that works is KROIL. read the can....guaranteed to penetrate one-one millionth of an inch. take it for what its worth...c-ya

 

[k3hal]

as a retired maintainence mechanic/machinist for the last 46 years, the ONLY penetrating oil that works is KROIL. read the can....guaranteed to penetrate one-one millionth of an inch. take it for what its worth...c-ya

obtw...Amazon carries KROIL!

 

[AB6CJ]

Thanks for the info.