[TenTec] USECA HF Mobile Antenna Shootout Results

[Paul Valko]

Hello folks,

I am forwarding this interesting pair of notes from my good friend Floyd, W8RO.  

It is great reading!  The hams listed below mostly belong to the USECA radio
club of Macomb County, Michigan.  USECA (except for this past year) runs the
world's largest QRP Field day.  A great organization you can check out at
www.useca.net

I hope you enjoy it as much as I did.  It needed to be shared, great work
Floyd!   73 =paul= W8KC

***********************************************************
Gang,

Here are the results of the HF Mobile Antenna Shootout that was held on 
Sunday, 23 Nov 2003.  The rules are the same as for the 3875 Shootout in 
Anderson on June 2004.  Generally, these are:  Max. Height above ground 
of 13'6".  No capacity hats.  Max. mast length of 7'.  Must be road 
worthy.  Test freq. 3.875 Mc.

There were at least 18 people there that I know of.

Test rig consisted of Icom 706 MKIIG w/Bird 43 wattmeter and cigarette 
lighter cord.  Test power was calibrated to 20 watts in RTTY mode.  Test 
antenna was same style loop as 3875 gang uses.  A big thanks goes out to 
Darrell, KA8LGI, for optimizing the loop so that it receives on the test 
frequency with MUCH better sensitivity than ever B4!  Loop was connected 
to diode detector box and is zener protected.  Rectified DC voltage is 
read with DVM.  For those tests that give 3 voltage readings, the 1st is 
20W FWD power and 0W (or minimum) REF power as indicated on the Bird 43. 
  The 2nd is retuning for maximum field strength reading on Darrell's 
portable loop sitting next to the passenger door of the test vehicle 
(w/o touching power setting).  This usually increases the FWD power 
reading, so the 3rd reading is with the FWD power reading corrected back 
down to 20W.

KA8LGI Antenna 2 (Coil elevated to limit)
2.175v - 2.237v - 2.119v

W8RO (tap 1)
2.084v - 2.196v - 1.189v (I think this is a typo...)

W8RO (tap 4)
2.049v - 2.138v - 1.958v (tap 2 & 3 was also close to this reading)

KA8LGI Antenna 1 (standard configuration)
1.894v - 1.946v - 1.817v

WB8E Webster Band Spanner - (legal height?)
1.848v w/nobody nearby
1.454v w/people standing near van

WB8X Texas Bugcatcher w/480 coil
1.742v - 1.815v - 1.663v

AA8CY Homebrew Screwdriver (Sm.)
1.745v

AA8CY Homebrew Screwdriver (Lg.)
1.714v

W1IK High Sierra Screwdriver
1.355v (standard stinger)
1.515v (long stinger - don't think it is legal height)

KC8LOC Hamstick
.495v

W8RO (tap 4)
(last voltage reading with no changes from 1st measurement to ensure 
repeatability)
1.861v (compared to 1.958v the 1st time)

KA8LGI Illegal antenna w/cap hat (just for testing purposes)
2.046v - 2.179v - 1.989v

Conclusions: Darrell is still DA MAN!  Floyd's configuration has been 
the same for the past 5 or 6 years, so his readings are still good 
references compared to Anderson, IN results.  He tested 4 different taps 
on his tuner with similar results.  The last reading on Tap 1 looks to 
ba an anomaly, as the other 3 readings are very close.  We will look at 
the information gathered here and see if any new conclusions are drawn.

Thanks to everyone that attended and participated.  We may try to get 
one more in B4 winter!  (As we say about the antenna systems) Stay 
tuned!  :-)

***********************************************
***  Floyd added this short note later...
***********************************************

Gang,

Let me make some clarifications that should be added to the results 
message.  (I typed it at 2:30 AM, so I wasn't quite as awake as I should 
have been! HI!)

The main reason that Bryan (AA8CY) and I are sponsoring these shootouts 
is to learn what works and what doesn't (and hopefully why).  We want to 
use the guidelines that the 3.875 gang have used for almost a decade 
now, just so we can lend some sort of consistency and so that our 
results can by loosely compared with Anderson, IN results. If there are 
systems (like mine) that have remained unchanged for a handful of years, 
they (it) can be used as a yardstick if someone wanted to compare their 
results here in Michigan with the results from Anderson.  We realize 
that the absolute numbers cannot be compared, but a "standard" system 
that has been unchanged can be used as a loose guideline to see if a 
system is in the ballpark or not.  In addition, we want to quantify 
whether changes made to individual systems are helping or hurting system 
performance.

I had made some brief comments about certain systems that may not be 
"legal" with regard to the 3.875 rules (which are spelled out on the 
3.875 web site).  One of the rules is the maximum height above the 
ground be no more than 13' 6", so the system can make it under most 
normal bridges on the freeways.  Another is that the system has to be 
driven to and from the test site (road worthiness) at free way speeds. 
For the Anderson test, this usually means many hundreds of miles!

A few of the antennas may not have been within these rules, so for those 
of you who are tracking "competition" results, you need to be sure to 
take these antennas out.  WB8E's Band Spanner was not legal, as it was 
not road worthy with a single magnet mount, this was just a test to see 
if this antenna still worked.  It DID!  W1IK's long stinger was probably 
too tall (we didn't get a chance to measure it).  KA8LGI's last (3rd) 
test was just to test a different design and it had a capacity hat, so 
it also cannot be included in the "competition."

We try anything and everything at our shootouts just to learn what's 
good and what's not so good.  I should have placed only the competition 
antennas in the order of finish and left the "illegal" antennas systems 
to a different category.  Sorry for the confusion!
-- 
73,
Floyd Soo, W8RO