Base SP 500 model finally comes together with the matcher.

[Marconi]

I've been fiddling with this complicated match on the Super Penetrator for some time, but finally I got it together.

I don't see the performance I was expecting, but believe it or not...the pattern is very close to what I see on my I-10K by Jay in the Mojave. The pattern also shows horizontal RF. See the black pattern in the antenna view. The pattern also shows some skewing which I figure is due to the mounting bracket design that raised the radials up on the base of the radiator.

I haven't compared then together yet, but I will.

 

[Marconi]

Here are the overlays comparing the SP500 to the I-10K. I also show a pattern view of the I-10K with both polarities turned on. Notice the I-10 with its very large trombone tuner shows much more horizontal in the pattern.

 

[HomerBB]

The first 2m antenna I put up in the air was a homebrew 5/8^ GP. It had a 4' vertical and 19.25" radials (x4). There was a aluminum cup, 4" diameter x 4" deep as the center hub turned cup opening down upon which the vertical and radials were mounted.

It did very well with a decent match, around 1.5:1 SWR. This was the typical tapped inductor type antenna. I mounted it 32' high.

We talked on 146.520 Mhz FM, then all of us went to 144.250 Mhz for SSB QSO. Of course, everyone else went horizontal for the SSB work, but having only my .625 GP I didn't. They were puzzled that I was as strong as I was from the GP. Perhaps the construction materials I used made some difference...

 

[Marconi]

Homer, at what frequency will your NV4K idea be resonant?

 

[HomerBB]

Trying to get it resonant on 146 Mhz.
Haven't tried it outside. Put the analyzer on it in the shop, but it was best with a 1.3:1 at 144Mhz. Can't do much with it until I get it outside the building (It's been raining for 3 days here). Also, my connections to the analyzer were a bit sloppy. Need to devise something more rigid. Soon.
Can you use the info I sent you to attempt a model in your off time?

 

[HomerBB]

Intend to use one of these fm radio antennas to find vertical tap point.

 

[Staybolt]

My cb neigbor down the road does not like his new spt 500. He says it seems flimsie compared to the one he had in the 1970s. I went out and looked and it has a permanent bow to the east from the winds so i see his opinion is valid. What do you guys think? Lets hear it.

 

[Marconi]

My cb neigbor down the road does not like his new spt 500. He says it seems flimsie compared to the one he had in the 1970s. I went out and looked and it has a permanent bow to the east from the winds so i see his opinion is valid. What do you guys think? Lets hear it.

I don't recall hearing any reports on performance for the current version of the SP500, but CB is dead in the Texas Gulf Coast area.

Time will tell if the company that build this antenna is using junk tubing.