Antenna question

[Superhero182]

Hey guys, I am a sidebander in Minnesota. I picked up a home base antenna from a family friend and it has great receive, I am able to make DX contact all over. However my SWR is totally messed up. I've raised my antenna as much as I can right now and my SWR is up in the 3s.

Some of the locals in our "club" said I needed the 3 radials that go on top of the antenna. I've never had them but I was hoping someone could point me in the direction of buying some. I don't know what my antenna brand is nor does it have any obvious markers but it looks JUST like this (minus the top radials)

 

[JayMojave]

Hello S182: Yes that looks like a CLR-2, one of the many models Hy-Gain made.

Attached is the Hy-Gain Manual, thanks to CBtricks.com.

Figure 6 shows the Top Hat Radials being installed, these radials are 10 inches long, and can be made out of wire that is used for hanging false ceilings, at Home Depot.

The Matching Coil is a thin copper trace on a circuit board wound in a circle, and will not take a lot of power, I guess at a few hundred watts. This matching coil is located inside the lower insulator, which uses steel rivets to mount it. These steel rivets can be drilled out and a better coil wound and installed, or even a matching system like the Hy-Gain Penetrator 500 uses, but that's not an easy modification.
New Bottom and Top Insulators are available from Hy-Gain, just look up the Penetrator 500 assembly instructions.

Hy-Gain changed its design of 5/8 vertical antennas to the Penetrator 500 and advertised a power handling rating of 1500 watts back in the day as there were a lot of the CLR-2 burn out. Even back in the 60's.

You should have the match right at 1 to 1.2 or close. Without the Top Hat Radials on the CLR-4 Antenna will make it work in the 28 MHz area, so using a Antenna Analyzer to see what frequency the CLR-2 is working at, and its Top Hat Radials and antenna height can be slightly adjusted for a lower SWR

Good Luck. Let us know how you make out.

Jay in the Mojave


http://www.cbtricks.com/ant_manuals/hygain/model_473/graphics/hy-gain_473_clr-2.pdf

 

[Superhero182]

Sorry, I am not as technically advanced with radios and antennas as a I wish I was. Does not having the top radials mess up my SWR or should I be address the issues elsewhere? I've always ran mobile rigs where it was super easy to tune the antenna so this is all new to me.

 

[JayMojave]

Hello S182: Yes you need the three top radials, at 10 inches long. These top hat radials lower the antennas SWR to work on the CB Band.

jay in the Mojave

 

[prcguy]

There are antenna versions that look similar but do not have the top hat radials. Does the top element have a threaded insert for a 6-32 or 8-32 screw?
prcguy

 

[BillMcE]

Yes, there are certainly versions without the top radials, so you may have one of those versions. I had this Colinear antenna in the 70s & I seem to remember them marketing the top radials as "static arresters," so if that's the case, they wouldn't have an affect on SWR. Matter of fact, one of mine broke off & it did not affect SWR at all. Personally, I think it's a gimmick & more of a design element. Just my 2 cents.

 

[KC4RAF]

prcguy, that top element accepts

a 10-24 x 1" round head screw. If you have access to the stainless steel screws, you'll be better off.
On the CLR-2 antenna I had years ago, the top hat radials did change the SWR; without them the numbers were high. And it was a really good antenna too, used it up till about '90 - '91, then went with the PDL quad.

 

[SpectreOZ]

Yes, there are certainly versions without the top radials, so you may have one of those versions. I had this Colinear antenna in the 70s & I seem to remember them marketing the top radials as "static arresters," so if that's the case, they wouldn't have an affect on SWR. Matter of fact, one of mine broke off & it did not affect SWR at all. Personally, I think it's a gimmick & more of a design element. Just my 2 cents.

"Capacitance hats" are hardly a gimmick and have been an aspect of antenna design since before 1900, their effect ranges from increasing bandwidth to altering input impedance and resonance length... of course the antenna will also work without their attachment.

Creating replacements can be done with simple coat hanger wire looped (small) at one end and cut to the required design length.

 

[mike_gain]

Are you sure it's a CB antenna?

 

[JayMojave]

Yes the Capacitance Hat is the real deal. When the Capacitance Hat is removed the CLR-2 Antenna will have the lowest SWR higher than the CB Band. Hy-Gain designed the matching network to match the antenna with the Top Hat or Capacitance Hat installed. It gives the antenna more of a capacitive load causing the antenna to work lower in frequency matching wise.

Again a Antenna Analyzer is a good call to use testing the antennas SWR, and seeing were it is.

Jay in the Mojave

 

[BillMcE]

I realize that the capacitance hat itself is the real deal. My point is that Colinear marketing them as "static arresters" was a gimmick. I'm wondering if the OP's SWR issues are being caused by something unrelated.

 

[LtDoc]

Pssst - A capacity-hat adds inductive reactance, not capacitive reactance. They effectively make an antenna 'longer'.
Doc

 

[JayMojave]

Pssst- Roger that I stand corrected! That's why the Top Hat Assembly will require less matching network for the 3/8, 1/2, and 5/7 wavelength GP antennas.

Jay in the Mojave

 

[prcguy]

A capacity hat adds capacitance and increases capacitive reactance in an antenna and effectively lengthens the antenna and reduces the amount of inductance needed to resonate at a particular frequency in addition to other benefits, but it does not add inductive reactance.
prcguy

Pssst - A capacity-hat adds inductive reactance, not capacitive reactance. They effectively make an antenna 'longer'.
Doc

 

[JayMojave]

Hello PRC Guy: Yes your right for very large Capacity Hats, I think. But the Top Hat or Capacity Hat we are talking about, are short 10 inch long radials, that are added to suppress static, and lower the antennas inductive reactance somewhat. Surly they increase the capacity seen, but significantly increase the inductive reactance. So as with all antenna parts and elements they have a complex impedance.

And I am not sure about the static discharge, but they must give some static discharge. I know they are not much help from rain noise.

A lot of things were not qualified here.

Jay in the Mojave