Metal CB base antennas

[prcguy]

The Hy-Gain Penetrator is a 5/8 wave antenna. I've read some notes from its project engineer on their design goals and what makes it a really good antenna and its inventors state its a 5/8 wave. These are not CBers but actual antenna engineering people.

The Hy-Gain Penetrator is a .64 wave antenna, that' why it has a little more gain than the 5/8 wave...

 

[stingray327]

The Hy-Gain Penetrator is a .64 wave antenna, that' why it has a little more gain than the 5/8 wave...

I liked the Hy-Gain Penetrator a lot better than the Sigma 5/8 base antenna.

 

[stingray327]

It's not illegal to own a metal CB antenna.. However, it is illegal to market a metal omni - directional CB antenna to the public.

Apparently through the right connections you can still get these antennas somehow. I have seen them put up by neighbors.

 

[stingray327]

As someone who has made a living designing and modelling antennas for the last 30 years, let me comment on the astroplane design.
This is essentially a top-loaded sleeve dipole. It will have (neglecting minor conductor losses) 2.1 dB gain over isotropic - the same as any other vertical dipole. The X on top is capacity hat loading, resulting in a shortened overall structure. The bottom skirt forms "the other half" of the dipole, or the "coaxial sleeve," decoupling the metallic mounting pole. It's a vertical dipole. The X could be done away with if the overall height was lengthened to a half wave.
No magic here - it's an honest antenna, but as so frequently happens with antennas marketed to consumers, the unique appearance can make or break economic success.

I believe this Astroplane antenna is a lot smaller than most ground plane base antennas at that time. It took up less space.

 

[MisterLongwire]

Penetrator and Sigma 5/8 were da bombe. My Shakespeare Big Stick worked awesome with my
PDL2

 

[russbrill]

The Hy-Gain Penetrator is a 5/8 wave antenna. I've read some notes from its project engineer on their design goals and what makes it a really good antenna and its inventors state its a 5/8 wave. These are not CBers but actual antenna engineering people.

Actually, when you do the math, physically the Penetrator is the correct length to be a 5/8 wave antenna. I have no reason to believe you're wrong. Hy-Gain used some kind of Hair-pin Impedance Matching network at the base of the antenna instead of a Coil of some type.

The confusion on my part: Rat Shack had a .64 wave antenna with the same physical measurements as the Penetrator, but Tandy used an Impedance Matching Coil at the feed point of the antenna. That Coil may have added to the electrical length of the antenna, that's how they got the .64 wave figure... Just a guess..

 

[stingray327]

Penetrator and Sigma 5/8 were da bombe. My Shakespeare Big Stick worked awesome with my
PDL2

When my Sigma 5/8 and Super Penetrator antennas went down because of rust I went with the Big Stik 1/2 wave antenna back in the day and it was very poor performance.

 

[russbrill]

When my Sigma 5/8 and Super Penetrator antennas went down because of rust I went with the Big Stik 1/2 wave antenna back in the day and it was very poor performance.

The Big Stick antenna had 0 DBd and your 5/8 wave antennas had around 3 DBd of Gain.. The only advantage the Big Stick had was simplicity of installation, there wasn't a lot to put together on that antenna...

 

[prcguy]

When I was testing these antennas in the 70s I lived on a steep hill about 300ft above sea level. A big stick at that location would give a slightly better signal at the base of the hill a mile away but the Penetrator would put out a noticeably better signal at a distance and better than any other omni I tested at that time. The radiation pattern of the big stick was obviously wider and it would also get into more home electronics than the Penetrator mounted in the same location above my roof.

The Big Stick antenna had 0 DBd and your 5/8 wave antennas had around 3 DBd of Gain.. The only advantage the Big Stick had was simplicity of installation, there wasn't a lot to put together on that antenna...

 

[russbrill]

When I was testing these antennas in the 70s I lived on a steep hill about 300ft above sea level. A big stick at that location would give a slightly better signal at the base of the hill a mile away but the Penetrator would put out a noticeably better signal at a distance and better than any other omni I tested at that time. The radiation pattern of the big stick was obviously wider and it would also get into more home electronics than the Penetrator mounted in the same location above my roof.

Yep, sounds like a Big Stick... Electrically I believe they were vertical half waves, possibly center-fed...

 

[prcguy]

Yes but I believe there is a length of non 50 ohm coax inside to help with matching.

Yep, sounds like a Big Stick... Electrically I believe they were vertical half waves, possibly center-fed...