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KQ6XA wrote:

No manufacturer is selling a better performing or
more versatile portable whip for the FT-817 at this
time, as far as I know. Anyone tried a better one?

Barry W4WB wrote:

Yes, I find the B&W AP-10A works somewhat better than the MP-1.

Now you have me intrigued, Barry!
How did you mount your B&W AP-10A on the FT-817? Is there a new B&W
FT-817 mount, or did you drill out the stock one?
Is the AP-10A different from the earlier "window sill antenna" they
have had for a long time? I think the earlier one required using tools
to move the frequency band taps, and for dis-assembly didn't it? Did
they change to 3/8-24 standard threads on the new one? That would
enable us to plug it into a regular mobile or MP-1 Superantenna FT-817
mount. Is the new one an "air dux" coil? How small does it pack up?

Bonnie KQ6XA

Wow, I guess I must play the Radio Shack guy --- You got questions, I
got answers! hi hi

See below please.

--- In FT817@y..., "KQ6XA" <xtalradio@a...> wrote:

KQ6XA wrote:

No manufacturer is selling a better performing or
more versatile portable whip for the FT-817 at this
time, as far as I know. Anyone tried a better one?

Barry W4WB wrote:

Yes, I find the B&W AP-10A works somewhat better than the MP-1.

Now you have me intrigued, Barry!
How did you mount your B&W AP-10A on the FT-817?

*** I didn't mount either antenna on the 817. Not my style. When I
am doing what I think you call PM, I go to a place a set up an
antenna, but not on the radio. I find it unpleasant to try working CW
while walking. :-)

Is there a new B&W FT-817 mount, or did you drill out the stock one?
*** Not that I know of. I see no reason at all why one could not
make a FT-817 mount for the AP-10A.

Is the AP-10A different from the earlier "window sill antenna" they
have had for a long time?

*** Yes. Long time is 40+ years!

I think the earlier one required using tools to move the frequency
band taps, and for dis-assembly didn't it?
*** Well sort of. You had to change coils in an inconvenient way in
the OLD version.

Did they change to 3/8-24 standard threads on the new one? That would
enable us to plug it into a regular mobile or MP-1 Superantenna FT-
817 mount.
*** No. The bolt in the coil bottom is a standard 1/4-20. It is a
trivial matter to make a transition part.

Is the new one an "air dux" coil?
*** Yes. The coil housing is PVC having an overall length of 7" as I
recall. The coil is 4" in length and 2" in diameter. Textbook
design.

How small does it pack up?
*** The bracket for window sill or table edge or ... is about 15"
long. The stainless steel whip is about 23" long when collapsed
(BTW, its diameter is about twice that of the MP-1 whip). It is a
bit more of a pain to pack, but is easily finds a home in my carry-on
suitcase fir airplane travel. No question that the MP-1 is the champ
of champs for packing small.

FWIW, I have frequently mounted the AP-10A on the edge of a table, a
2x4 in the clamp with a few bricks sitting on the exposed parts of
the 2x4, in hotel windows, etc.

72 de Barry - W4WB

Bonnie KQ6XA

The bolt in the coil bottom is a standard 1/4-20. It is a
trivial matter to make a transition part.

Or, to drill out the hole and tap 3/8-24. Should be enough
stock left for that (though I think I'd prefer not to do it
with a hand drill).

Getting back to the bigger topic, though, as someone
mentioned, I think it is fair to say that the AP-10A is not
a magic bullet. The coil may have slightly higher Q and the
instructions may help getting it tuned faster, while the
MP-1 is more compact and has nice mounting hardware. Both
need care and skill to get predictably good results.

I bought some 3/8 aluminum rod stock last night and am going
to make up a couple of extension rods for experimenting with
the MP-1.

73
John Newell
KB1FPM

Hi John,

I believe what Bonnie was asking me was if the B&W coil could be
mounted in place of the MP-1 coil. That is the reason for the 1/4-20
to 3/8-24 converter.

I forgot to mention that the current B&W coil is easy to use compared
to the older version. It has a fly lead that just attaches to the
place you desire on the coil.

I agree that the AP-10A is not a magic bullet nor is any other whip.
For those interested in small loaded whip-like antennas, reading of
the sections regarding mobile antennas in the ARRL Antenna Handbook
and the like is a great place to start. In short, the radiation
efficiency for shortened whips is rather low. However, at even 3%,
it is down by about 2.5 S-units from an antenna having 100%
efficiency. When the band is open, it is not such a big deal.

The use of extension rods is a good idea. You can move the coil more
towards the center and realize different characteristics. Since you
have a RF-1 analyzer as I recall, you will be able to observe the
effects of coil position.

In another post, Nick mentioned the old technique of using caps at
the base to null out the reactance. I'm not sure of the value of
doing this with the baseline MP-1 since I have found good tuning by
simply using a good tuned counterpoise. I further note that keeping
the "radials in a wad and moving them around to get minimum SWR" is
just providing the needed capacitance. Of course, the radiation
efficiency will be found lacking.

72 de Barry - W4WB