Hy-Gain SPT-500 Super Penetrator Question

[The DB]

You are suggesting there is a fix for the TVI problem, but you don't tell us what it is.

Can you share that fix with us and tell us what really causes the TVI...if it is not something wrong with the antenna?

That depends. If the cause is your radio (and/or amplifier) is causing splatter from DC to daylight, you fix the splatter problem with your equipment. If it is because the antennas are very close, you separate them, or at least reposition them so the CB antenna is in the TV antenna's null. If the problem is in the TV itself, you lower your output power, or move your antenna further away from the TV, a lot of times higher works well. If the problem is because you have CMC's coming down the feed line you fix the CMC issue. If the issues is with cable TV, I have seen water damaged cable TV coax cause it to be more sensitive to interference, you fix said coax, or you get the cable company to do it. If the cause is something attached to the TV (or reslly any device that is getting interference) has a wire that is resonant or near resonant on CB frequencies you use a different length wire or get snap on ferrite beads to change said wire's resonant length. I can go on here.

Their isn't only one possible fix, it really depends on the specific setup, and the cause of the problem.


The DB

 

[Marconi]

Very good Steve...now I understand more of what you meant.

Thanks.

 

[Ranch55]

Ranch55, thanks for resurrecting this old thread. I just read it from the beginning again and found it very interesting.

Why don't you share your "Fix" with us...there could be a few with similar issues and a little new info might help them too.

What I have found to cause the high SWR's when the antenna gets wet, is not enough separation from the vertical to ground at the top insulator.
I have used some self sealing silicone coax wrap and covered the top of the insulator and wrapped up about 6 inches or so. Did the same on the bottom side down about 4 inches or so. I then wrapped that with some Scotch 88 UV resistant tape.
Adding this extended insulation wrap above and below the insulator keeps my SWR's down even when raining and wet.

 

[Ranch55]

And then .......
I have another "mod" for increased power handling capability on the Penetrator.
Out of the box, I found the limiting factor to also be the upper insulator, which I have blown a hole thru before.
I have acquired some special , extruded Teflon tubing, same I.D. and O.D. as the insulator. It has very high electrical and RF insulating properties, as well as weather and UV resistance.
Replaced the upper insulator with about a 8" ~ 9" long piece of Teflon. In addition to increasing the connector input wire size in the lower insulator with 12 ~14 ga. silver coated wire, this increased the power handling capability on the Penetrator.
My SWR reading is consistently at 1.0 : 1 to 1.1 :1 ..... wet or dry.
I use some very expensive Array Solutions Power/SWR meters ......

 

[Marconi]

I have removed several old HG CLR antennas with raised radials and the top insulator is often cracked or broken. I never saw one that looked burned though.

The top part of the mounting bracket with the long radials attached is really put to the task with wind and weather, so this top insulator really takes a beating.

I have found the base insulator burned and split however, and suspected lightening.