| Author |
Message |
    
Tech833
Intermediate Member
Username: Tech833
Post Number: 131
Registered: 12-2001
| | Posted on Friday, November 13, 2009 - 11:23 am: | 
|
Most of you guys may have seen the article I wrote recently regarding the 'famous' Penetrator P500 antenna - http://www.copperelectronics.com/cgi-bin/discus4/board-auth.cgi?lm=1255966297&file=/7750/111489.html
You may not know that years ago, I was asked to review the Interceptor 10K (also known as the I-10K) by Jay in the Mojave. I presented a full review, including testing on the antenna range to determine the radiation pattern. The article was never published since Jay was unhappy with the results, and that I could not confirm the 10 dB gain claims.
Without getting into great detail, I found the old polar plots for the 10K and it was very interesting to compare the 10K to the Penetrator P500. Both plots are below. First, the 10K, then the P500. As you can see, the 10K and the Penetrator P500 have EXACTLY the same gain on the horizon. The 10K is very slightly more efficient than the P500, but any extra RF seems to be focused below the feedpoint, not on the horizon where it is needed. The 'trombone tuning' efficiency increase is offset by sending energy downward.
I also included the plot for the Imax 2000 with the GPK added (third image). I find it very interesting that the Imax has only slightly less gain than the Penetrator P500 or the I-10K. However, for that minor gain difference, you get MUCH better bandwidth out of the Imax 2000, and much easier tuning and installation.
One of these days, I might order a Maco V-5/8 and get a plot on it too and add it to the comparison. However, in computer modeling, the V-5/8 performs almost exactly like the 10K and Penetrator P500.
Interceptor I-10K:
Penetrator P500:
Imax 2000 w/GPK:
 |
Sitm
Intermediate Member
Username: Sitm
Post Number: 325
Registered: 1-2004
| | Posted on Friday, November 13, 2009 - 11:33 am: |
|
Great information, thanks for posting it |
Airplane1
Senior Member
Username: Airplane1
Post Number: 1364
Registered: 5-2004
| | Posted on Sunday, November 15, 2009 - 4:44 pm: |
|
Great ifo. I wish I had the extra $ to buy and send you a Maco 5/8 for testing. It would be worth it to see what the facts are.
Roger |
Dale
Senior Member
Username: Dale
Post Number: 1519
Registered: 12-2002
| | Posted on Sunday, November 15, 2009 - 6:39 pm: |
|
i would have like to seen the maco also
dale/a.k.a.hotrod
cef426
cvc#64
|
Road_kill_radio
New member
Username: Road_kill_radio
Post Number: 3
Registered: 7-2011
| | Posted on Thursday, September 15, 2011 - 5:34 am: |
|
I cant believe how often I read someone claiming the 19' 10" Maco V-5/8 style .55 wavelength GP performs as well as the Penetrator or I-10K.
I have had these five (and more) on my test mast and the difference in performance between the Maco / Workman / JetStream V-5/8 versus ANY full size 5/8 - .64 is OBVIOUS, a good 1.5 S units on a typical meter, as high as 2 S-units on my Icom IC-761, 1 S-unit on a Tram 40 ch AM mobile meter and right at 1.5 S-units on my Yaesu FT-990, and a blinking 1 to 2 S-units on the Icom 746 digital meter. |
Dale
Senior Member
Username: Dale
Post Number: 1774
Registered: 12-2002
| | Posted on Monday, October 24, 2011 - 8:31 pm: |
|
roadkill i believe the s-unit thing but
the maco tuned for 11 meters is 20.5 feet or
248 inches.
dale/a.k.a.hotrod
cef426
cvc#64
|
Rumblefish
Junior Member
Username: Rumblefish
Post Number: 47
Registered: 12-2002
| | Posted on Thursday, October 27, 2011 - 2:09 pm: |
|
looks like the .64 wave is wasting power at at a higher take off angle than the 5/8ths wave antennas.If all .64 antennas have similar radiation plots,i'm sticking with the 5/8ths wave ground plane antennas because they put more signal at the horizon. |
J_a_f_0
New member
Username: J_a_f_0
Post Number: 1
Registered: 9-2017
| | Posted on Friday, September 22, 2017 - 12:00 am: |
|
Hey Tech833,
- I'd like to know what parameters you plugged in for the Imax. |
Tech833
Moderator
Username: Tech833
Post Number: 2388
Registered: 8-2002
| | Posted on Thursday, October 05, 2017 - 2:15 am: |
|
I used data gained from having the Imax on the test range. I did not use arbitrary or published data.
Your radio 'Mythbuster' since 1998
|
Chrisbama351
New member
Username: Chrisbama351
Post Number: 6
Registered: 2-2018
| | Posted on Sunday, February 17, 2019 - 3:08 am: |
|
Is the Penetrator both a horizontal and vertical antenna at the same time?
Is there a name for antenna's that are both?
Looking for a stainless steel rod 0.25 x 18' to use as a whip antenna.
|
Tech833
Moderator
Username: Tech833
Post Number: 2430
Registered: 8-2002
| | Posted on Sunday, February 17, 2019 - 2:03 pm: |
|
No. The Penetrator is a 5/8 vertical. The ground planes do not radiate RF in the horizontal plane.
An antenna that radiates both vertical and horizontal at the same time (splitting the power between two polarities) can either be a dual-polarity antenna or a circular polarized antenna.
Most US FM broadcast stations use circular polarity (vertical and horizontal at the same time in phase so the signal would appear to 'rotate').
A circularly polarized antenna would have about half the gain as a 1/2 wave dipole using single polarity. However, you can vertically stack circularly polarized antennas 1/2 or 1/0 wavelength apart and feed in phase to bring the gain back up.
Your radio 'Mythbuster' since 1998
|
Centurion
Junior Member
Username: Centurion
Post Number: 15
Registered: 7-2020
| | Posted on Sunday, January 03, 2021 - 10:15 am: |
|
The penetrator has as well as the trombone match a wire that goes from the ground plane attachment plate to the feed line connector on base is this correct or am i seeing things that are not there I am rebuilding a penetrator that has some parts missing and want to make sure it is right! if the radials don't radiate RF what is this wire to them for? |
Tech833
Moderator
Username: Tech833
Post Number: 2480
Registered: 8-2002
| | Posted on Sunday, January 03, 2021 - 6:03 pm: |
|
There is an article here on how to rebuild a Penetrator antenna. It shows what that wire does very clearly. http://www.copperelectronics.com/discus4/messages/7750/111488.html?1426251663
The wire between the "hot" and ground is the shunt. The wire you describe is the phasing stub. Neither of those makes the ground planes radiate.
Your radio 'Mythbuster' with Copper Electronics since 1998
|
Centurion
Junior Member
Username: Centurion
Post Number: 16
Registered: 7-2020
| | Posted on Sunday, January 03, 2021 - 10:09 pm: |
|
Thanks 833 I was looking at the photos on the post you mentioned an was asking to make sure because the second wire the one not trombone shaped is the one i was missing and wanted to make sure i was seeing the connections correctly Thanks again for your help almost done putting the base part of this back together! |
Thespacemann
Junior Member
Username: Thespacemann
Post Number: 13
Registered: 6-2016
| | Posted on Saturday, February 13, 2021 - 4:11 am: |
|
Is it true that they changed the IMAX antenna and made it shorter? |
Tech833
Moderator
Username: Tech833
Post Number: 2490
Registered: 8-2002
| | Posted on Friday, April 02, 2021 - 2:20 am: |
|
That would be news to me
Your radio 'Mythbuster' with Copper Electronics since 1998
|
Lonestarbandit
Intermediate Member
Username: Lonestarbandit
Post Number: 114
Registered: 10-2006
| | Posted on Saturday, April 10, 2021 - 1:35 pm: |
|
I bought a new one but sadly dont remember what my old ones measurements were years ago but if they did it seems to work about as well as I remember the old one working. |
Twa77
Intermediate Member
Username: Twa77
Post Number: 146
Registered: 1-2003
| | Posted on Sunday, April 11, 2021 - 12:22 pm: |
|
I have an old 1 in the basement I can measure. |
Cedar_mountain_radio
New member
Username: Cedar_mountain_radio
Post Number: 1
Registered: 4-2022
| | Posted on Friday, April 22, 2022 - 8:26 pm: |
|
Dale you wrote,
"roadkill i believe the s-unit thing but
the maco tuned for 11 meters is 20.5 feet or
248 inches."
I believe he was referring to the radiator length only, not the entire length of the Maco including the mounting base.
I have also found it tunes correctly for ch19 at 19' 10" from the beginning of the radiator as it leaves the base. |
Dale
Senior Member
Username: Dale
Post Number: 2428
Registered: 12-2002
| | Posted on Sunday, May 29, 2022 - 8:17 am: |
|
cedar , you could be right... this was from many years ago..the lenth i quotedc is right from the manual.
dale/a.k.a.hotrod
cef426
cvc#64
454 [dx numbers]
38lsb
|
