Topband: Notes on early JA to East Coast QSO's

[Herb Schoenbohm]

Earl K6SE said:
"My farthest east QSO was also my first 160m QSO from there -- Herb, 
W0VXO (now KV4FZ) in Minnesota was able to copy my homebrew 100-watter on
October 3, 1966.  Herb's big signal from his shunt-fed tower made me
decide that would be the way to go when I got back to the lower 48."

I remember this QSO with KL7FRY well because to me (W0VXO) working Earl 
on Shemya was almost like working JA on TopBand.  It encouraged me to 
believe it could happen even from the tundra of Minnesota as was the 
case later.  There is one thing that has now become a mystery.  My 100 
foot shunt fed tower (with a 4 element Quad with a 40 foot boom for top 
loading) was shunt fed in a very unique manner.  My shunt wire ran 
inside the tower dropping straight down from the rotor plate and pulled 
tight with an insulator and spring.  The wire was matched with a bread 
slicer and was strapped over to one of the tower legs up about 60 per 
cent.  I raised this feeding method some years ago on this reflector and 
the gurus all agreed that it just would not work since all I had was a 
shorted transmission. But it did work as evidenced by Earl's comments. 
(I believe even Earl saw the feed when he came for a visit in the 60's
It was for me a high performance DX antenna judging by world wide 
contacts on all continents from a difficult DX QTH.  European contacts 
were plentiful and I remember working all continents in one weekend.

I will probably get flamed again but there has got to be some 
explanation for this working as well as it did.  The reflected power was
1.2 to 1 and I am curious if this was a mere shorted transmission line 
where was the power going.  The only thing I can think is that I may 
have had an imperfect tower ground through the concrete and the tower 
was sort of floating above ground at RF.  I had only a few radials 
connected to a single ground rod at the base but don't recall if their 
was a large strap to the tower or not.

Maybe someone would be able to model this feed method.  I believe the 
gurus in theory but still worry about something working well when it 
isn't supposed to.  If you have any thoughts on this please let me know.

73

Herb Schoenbohm, KV4FZ

P.S.  In 1968 still as W0VXO I had a short vacation in Durango, 
Colorado.  The ease of working JA's by the scores day after day with 
only a 40 foot high inverted L 1/4 wave, compared to the Mississippi 
basin midwest never ceases to amaze me.  Stew Perry, W1BB said that it 
meant everything to be able to skirt around the Auoral Oval.  Perhaps 
this is why some of the recent reports of East Coast JA's show a 
preference to west or even south west Beverage reception.