StackMatch User WC4E

Notes on the StackMatch box at WC4E
Date: Mon, 9 Feb 1998 21:41:46 -0500
From: "Jeff WC4E" <wc4e@innet.com>
To: "Jay WX0B" <wx0b@arraysolutions.com>




Hi Jay!
Just wanted to drop a note to let you know how the StackMatch boxes
are performing. Sorry for the delay, but wanted to wait until after
the fall season to get a good idea how these were really working.
In short: I love these boxes!!
--------
Here's my 10M set up:

Cushcraft 4 element at 125', 100' and 75'
Top fully rotatable, other 2 fixed NE (or DX contests)

Coax: LMR 400 Sm to Antennas: 1 1/2 WL = 44'-6"
Approx 160' from Shack to SM box.

Switched 3 way with the SM box. All antennas have a good
SWR curve 1.3 at 28.0 mhz 1.5 at 28.7 with 1.1 at 28.300.
With the antenna in any switch position no major difference
was found in the SWR curve or matching. My amps love that!

Here's how the 10M stack performed so far:

CQ WW CW 1997

Single op All Band: 3830 high claim to be 12th Place USA
From 3830 reports and breakdowns, I have highest 10M score so far
of all the other single ops.


ARRL 10M 1997 (My favorite Contest!)

Single Op, Mixed mode, High Power

Made 2753 QSOs an 195 mults.
Reports from 3830 high claimed show a comfortable number #1 USA
and #2 in the world, also beating all multi ops worldwide.

For the ARRL10M I had the 4el at 100 fixed N and the 75' was fixed NW.
I also had a 4th 4el and 50 fixed SE fed with a separate feed line.
The stackmatch provided superior "direction" switching flexability.
Having the abilty to switch quickly from N to NW to NE or any combo
inbetween was an edge I needed in this contest. Conditions change
rapidly on 10M, it is very important to be ready for any opening
in any direction, the WX0B StackMatch box provided that edge!

---------------

15 Meters

On 15 I have Cuchcraft 4/4 stack at 125'/70'
Top is fully rotatable, Bottom is fixed NE to EU.

I tried the In phase/Out of Phase switching method with StackMatch.
The BIP/BOP is working very well given the wide spacing of the antennas!

Both Antennas are exactly the same phsically, but give a little
difference in SWR curves

Freq Top Bottom BIP BOP All 3
------ ----- ------ ---- ---- --------
21.000 1.25 1.6 1.2 1.2
100 1.15 1.4 1.15 1.15
21.200 1.1 1.3 1.2 1.2 4:1 Caution!!
300 1.2 1.4 1.3 1.25 (Do not use all 3)
21.400 1.3 1.4 1.3 1.3
450 1.35 1.5 1.4 1.35


All Feedlines are LMR 400:
Antennas to SM was 1 1/2 WL = 59.178' at 21.200
The phase line worked out to be 19' 6" at 21.200 measured
with an Autek RF1.

The bottom antenna SWR is a little different due to the interaction
with the steel guys wires around it. Will replace with "Phillystrand"
within a couple years

The BIP/BOP action does a good job of "hiding" the higher SWR
in the lower antenna, can't figure why.

Contest results to report:

CQWW SSB 1997:
Single op 15 Meters high Power.
WC4E 1311 QSOs 34 zones 137 countries for over 610K
#rd USA Narrowly missing second place USA. Was second in QSOs.
Beat K1KI's M/M QSOs on 15M

CQWW CW: Excellent results on 15M! Top 10 on 15M results.

SS CW: Top 20 USA HP, Worked VY1JA in BOP mode on 15M

Other operating notes and observations...

Given the wide spacing of the stack, the BIP/BOP switch was
very noticable:

DX stations (EU) were almost always louder when in in BIP mode,
by at least 1-3db at most times.

USA stations are almost louder when in BOP mode. A very pleasent
suprise!! Even when top is NW to JA and Low is NE, BOP is better!

Only downfall:
Selecting all 3 is not the thing to do, 4:1 SWR is result!
The BOX must by clearly labeled to which is U/L/BIP/BOP.
This could be a problem if power is lost to the box or the control
cable is disconnected.
A dedicated BOX designed for BIP/BOP may help this for people who
only have 2 antennas.

Another wierd thing I can't explain: signals to the lower antenna
*through* the phasing line are stronger than directly to the antenna!

Over all I am very happy with the Stack Match boxes. I will be adding
a lower 20M antenna and another StackMatch box!

I love the simplicity of connections! I've seen other large stacks
that require at least 5 phasing lines which can result in many more
points of failure.

I may add a 3rd 15M antenna at 100' to make it a "3 stack" Not
sure if I want to do this, I like the BIP/BOP ability.

Thanks for creating a simple and effective device!
Keep up the great work!

73
WC4E Jeff Bolda
wc4e@innet.com
For more shack info:
http://lucky.innet.com/~wc4e/index.htm