Topband: Pennant performance observations/issue

[w2pm at aol.com]

The following activities about Pennants resulted in me noticing a 
shielding effect from nearby objects to the antenna which is 
significant, and also raises a question over high angle/low angle 
reception performance mapped to physical obstructions. I have long 
wondered about local terrain contributing to poor performance on very 
low angle signals - not sure this answers those, however...

Recently I installed another point fed Pennant to 200 degrees - just a 
bit west of due south from NNJ. I have another similar one 200 feet 
away to 20 degrees - a bit east of North.  These directions simply 
follow the shrubbed property borders in the front part of my lot.  Each 
antenna is fed with identical 16:1 xformers - the binocular one's 
described by Tom W8JI. Great isolation and nearly flat low SWR nearly 
 from 160 thru 30, and beyond. I do not believe there to be any line 
pickup.

Each antenna exhibits textbook, Eznec performance based on extensive 
experience and somewhat careful but not precision measurement - both 
day and night. In fact the F/B is so good on 6Mhz - Radio Havana and 
Radio Prague each have huge over S9 signals at night at the same time - 
with A/B to each antenna it's like a channel selector to each station. 
Similar results on 1.8 with amateur signals in those directions. I've 
also verified the cardiodal pattern on BC stations rotating the antenna.

Interesting issue on the new 200 degree one tho - when listening to 
(2.5 mhz) WWV and WWVH (both at 280 degrees) - there's a 4 - 5 S unit 
null compared with the 20 degree antenna. This belies the cardiod's 
pattern to 280 on both. Looking only at the horizontal polarization 
Eznec model doesn't explain it either). There should only be a -6dB or 
so decrease from maximum "gain" in the 280 direction. Copy is great on 
the 20 deg.  However, on very distant VK and ZL sigs, 1.8 and 7mhz, the 
200 degree antenna is 3 - 5 S units GREATER than the 20 degree one!.  
Similar results on various freqs from 2 - 10 mhz.  SO, the 200 deg 
antenna has a notch to the west except on long haul DX at the grey line 
- so presumably high angle.

Note the 200 degree antenna is installed 20 ft "east" of a neighbors 
house with aluminum siding, and almost 1/3 of it's 29 ft length is 
adjacent to that building.  It's my opinion the house is physically 
blocks signals to the west (signals to the SW are fine).  The house is 
about 30 ft deep and the rear is completely open to the NW and N but I 
have not found any Seatlle area or JA signals to test on yet. If Im 
correct they should behave normally with the projected pattern.

Given the identical NNE antenna shows no pattern anomolies, and the SSE 
antenna appears "normal" otherwise, and performing well, this is my 
only conclusion. I also not there is no impact on SWR on the SSE 200 
degree antenna- about the same as the other, 1.2:1 pretty much 1.8 - 
4Mhz, then a wee bit higher and a little bumpier up to 10 mhz and 
beyond, but never higher than 1.8:1.  This is somewhat per various 
texts.    My Steppir beam which used to be installed in the same spot 
next to the Alum sided house, even at 30 ft ABOVE that house, showed 
significant SWR impact when rotated in that direction.  The Pennant 
does not BUT clearly is blocked there to low angle signals..

Anyone having any contrary opinions to my conclusions?

My FLags and Pennants (even a 1/2 sized model) remain critical assets 
to working 160 from this very dense suburban area.


Pete W2PM
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