Anyone want to buy a used MP-1? :-)
--
Julian, G4ILO. (RSGB, ARRL)
Home page:
Hmm I wouldn`t sell mine Julian.
Julian - I did some computer modeling of the MP1 a while back, and
found a BIG difference in making the lower mast about 3' long
instead
of the 10" stock length - like over 6 db on 7 mhz and decreasing to
about 3 db on 28 mHz (in fact, the performance should be sililar to
what you nboted on the Pro-am, as they would then be about the same
physical size). I have not found the MP1 to be as fussy about the
ground plane as the ATX, and the it certianly is more efficent,
even
with the short lower section, on 10, 18 & 24 mHz. I use 4 radials
18'
long of 18 guage wire.
I've tried different counterpoise solutions, but the best seems to
be
a "roll-up" counterpoise made from a Radio Shack short wave
antenna -
no problem getting it to work on the MP1, but the ATX is EXTREEMLY
fussy - actually, the only way I can get the SWR anything close to
low on 14 mHz is by adjusting the length and then bring the end
back
to near the rig..... putting it out in a straight line doesn't work
at all unless the whip on the ATX is made about 6" longer with a
clip
lead - similar problem on 21 mHz. On 7 mHz, it is not fussy about
the
groundplane and presents a reasonalble match across the whole band -
so does a dummy load!!! The MP-1 has a definite bandwidth that is
MUCH narrower, which means the coil is higher Q, and therefore
should
be more efficent.
Yes - a dipole would be better - just as long as you have a place
to
put it up. But also not as easy to change bands. And I shudder at
the
thought of adding gear to the package in the form of an ATU. I am
very happy with the MP1 and the clamp mount or tripod - lets me get
the antenna outside in the clear, tunes easily, performs well.
I'll trade you my ATX for your MP-1 anyday
Don
W6ZO
Well Don,
I felt exactly like you when I first got my ATX, after having being
spoilt by the MP-1 but I decided to keep the ATX, which is very small
and because of this I have it always in the same small bag I carry my
FT-817. It is OK for inter European or short distance NVIS QSOs (by
tilting it so it is nearly parallel to the ground), but if I want to
get outside of Europe I use the MP-1, which is clearly a better
performer when on the field, even when used with the 8.5 inch base
section. Another good thing about the MP-1 is that you can add things
to it and you can make it have a longer base section. The only band I
have not managed to obtain low SWR yet is 80 meters, but I have not
tried hard enough yet because I have not operated on 80 very much
yet. So I am keeping both for now!!!
73 de Demetre SV1UY
