Red Wave Radio

Hi.

(For those of you who see this two or three times, it is
because your news service does not properly cancel posts.
I made mistakes the first two times, and then cancelled them.
So if you do see this multiple times, please ignore the
previous copies of this post.)

I am wondering if anyone knows anything about using Radio
Shlack's telescopic, center-loaded whip antenna (catalogue
number 20-006) with the HTX-202 portable 2M rig.  According to
the HTX-202 manual, the portable rig should be usable with this
antenna.

So I bought one, thinking that it might be a better antenna for
hand-held portable use, than the "*** duckie" that comes with
the rig.

The instructions that came with the antenna indicate that it
should be adjusted to a certain length according to a formula
(I forget the exact formula quoted in the instructions; but it
was something like antenna-length(inches) = 28?? / freq(MHz),
but I forget the last two digits of the numerator).  The
instructions also mentioned something about that the section
immediately above the loading coil should be collapsed for
transmission.  (Now why should that be?  Does this mean that the
whole antenna above the loading coil should be collapsed, or
that just the single section immediately above the loading coil
must be collapsed, but the other sections above that can be
extended?)

What the instructions completely failed to mention is where
should the loading coil be along the length of the antenna
when it is adjusted for a particular frequency?  It only
gave a formula for what looks like overall length.

Does anybody have any experience using this antenna with the
HTX-202?  If so, can you please fill me in on how to exactly
configure the antenna?  (Maybe I should just return the
antenna and try to get a better one somewhere else?)

An E-mail copy of your follow-up would be greatly appreciated.

TNX ES 73,
Ed Pugh (VA3PU)



--
Ed Pugh           | "A common mistake that people make when trying
Ottawa (Richmond) | to design something completely foolproof, is to
Ontario, Canada   | underestimate the ingenuity of complete fools."
                  | - Douglas Noel Adams, 1952 - 2001 :-(

Quote:> Hi.

> (For those of you who see this two or three times, it is
> because your news service does not properly cancel posts.
> I made mistakes the first two times, and then cancelled them.
> So if you do see this multiple times, please ignore the
> previous copies of this post.)

> I am wondering if anyone knows anything about using Radio
> Shlack's telescopic, center-loaded whip antenna (catalogue
> number 20-006) with the HTX-202 portable 2M rig.  According to
> the HTX-202 manual, the portable rig should be usable with this
> antenna.

> So I bought one, thinking that it might be a better antenna for
> hand-held portable use, than the "*** duckie" that comes with
> the rig.

> The instructions that came with the antenna indicate that it
> should be adjusted to a certain length according to a formula
> (I forget the exact formula quoted in the instructions; but it
> was something like antenna-length(inches) = 28?? / freq(MHz),
> but I forget the last two digits of the numerator).  The
> instructions also mentioned something about that the section
> immediately above the loading coil should be collapsed for
> transmission.  (Now why should that be?  Does this mean that the
> whole antenna above the loading coil should be collapsed, or
> that just the single section immediately above the loading coil
> must be collapsed, but the other sections above that can be
> extended?)

> What the instructions completely failed to mention is where
> should the loading coil be along the length of the antenna
> when it is adjusted for a particular frequency?  It only
> gave a formula for what looks like overall length.

> Does anybody have any experience using this antenna with the
> HTX-202?  If so, can you please fill me in on how to exactly
> configure the antenna?  (Maybe I should just return the
> antenna and try to get a better one somewhere else?)

> An E-mail copy of your follow-up would be greatly appreciated.

> TNX ES 73,
> Ed Pugh (VA3PU)

From my experience telescoping whips are extremely ineffecient.  The ***
duck that comes with the 202 is actually pretty good.  My suggestion is to
buy a quarter wave *** duck if you are looking for somthing more than
what the stock antenna will do.  Then again it is an HT is does have
limitations.

The first section above the coil is left down to short out the coil, as it
isn't used on 2m frequencies.. a good length for the overall antenna is
~19". This makes a 1/4 wave antenna with the required ~50 ohm impedance.

I found that it I extended the top whip all the way, then pushed the section
directly above the coil back into it, was the perfect length for reception
on a Yaesu hT I have.

Cheers,
Andrew

Hi.

(For those of you who see this two or three times, it is
because your news service does not properly cancel posts.
I made mistakes the first two times, and then cancelled them.
So if you do see this multiple times, please ignore the
previous copies of this post.)

I am wondering if anyone knows anything about using Radio
Shlack's telescopic, center-loaded whip antenna (catalogue
number 20-006) with the HTX-202 portable 2M rig.  According to
the HTX-202 manual, the portable rig should be usable with this
antenna.

So I bought one, thinking that it might be a better antenna for
hand-held portable use, than the "*** duckie" that comes with
the rig.

The instructions that came with the antenna indicate that it
should be adjusted to a certain length according to a formula
(I forget the exact formula quoted in the instructions; but it
was something like antenna-length(inches) = 28?? / freq(MHz),
but I forget the last two digits of the numerator).  The
instructions also mentioned something about that the section
immediately above the loading coil should be collapsed for
transmission.  (Now why should that be?  Does this mean that the
whole antenna above the loading coil should be collapsed, or
that just the single section immediately above the loading coil
must be collapsed, but the other sections above that can be
extended?)

What the instructions completely failed to mention is where
should the loading coil be along the length of the antenna
when it is adjusted for a particular frequency?  It only
gave a formula for what looks like overall length.

Does anybody have any experience using this antenna with the
HTX-202?  If so, can you please fill me in on how to exactly
configure the antenna?  (Maybe I should just return the
antenna and try to get a better one somewhere else?)

An E-mail copy of your follow-up would be greatly appreciated.

TNX ES 73,
Ed Pugh (VA3PU)



--
Ed Pugh           | "A common mistake that people make when trying
Ottawa (Richmond) | to design something completely foolproof, is to
Ontario, Canada   | underestimate the ingenuity of complete fools."
                  | - Douglas Noel Adams, 1952 - 2001 :-(

Thanks for your follow-up, Brenda Ann.

I had not known nor realised that collaspsing the first section
above the coil would short it out, but, of course, that makes
perfect sense when you think about it (as I should have).

The RS instructions give the forumla for the length as:

length(inches) = 2834/freq(MHz)

which works out to 19.3", which is just about right according
to your follow-up.

Someone else suggested (by private E-mail) attaching a 14"
"tiger tail" ground to the BNC connecter.

Thanks again,
Ed (VA3PU).

--
Ed Pugh           | "A common mistake that people make when trying
Ottawa (Richmond) | to design something completely foolproof, is to
Ontario, Canada   | underestimate the ingenuity of complete fools."
                  | - Douglas Noel Adams, 1952 - 2001 :-(

234 / freq is a quarter wave. But having a loading coil confuses this I
would think.

  The

Quote:> instructions also mentioned something about that the section
> immediately above the loading coil should be collapsed for
> transmission.  (Now why should that be?  Does this mean that the
> whole antenna above the loading coil should be collapsed, or
> that just the single section immediately above the loading coil
> must be collapsed, but the other sections above that can be
> extended?)

If they don't specify, I would think the whole section should be
collapsed.

Quote:

> What the instructions completely failed to mention is where
> should the loading coil be along the length of the antenna
> when it is adjusted for a particular frequency?  It only
> gave a formula for what looks like overall length.

That probably applies with the top section collapsed.

Quote:

> Does anybody have any experience using this antenna with the
> HTX-202?  If so, can you please fill me in on how to exactly
> configure the antenna?  (Maybe I should just return the
> antenna and try to get a better one somewhere else?)

It sounds like an antenna made for wide range SWL or scanner use. I'm
not really familiar with it, but there isn't really a need to change
antenna length for a 2m FM HT. If there is no need for such a wide range
of receiving, I'd trade it in and get a higher performance 2m antenna
for the HT. The 1/2 wave types like the Hot Rod, etc are pretty good.
The 5/8's have some problems in theory with the ground return, but even
those will outdo the average *** duck by a large amount. Maybe you
could fine tune your present antenna with one of these new fangled
antenna analysers. I would think you could get close enough for gov
work. Maybe you could borrow one somewhere. MK
--
http://www.redwaveradio.com/~nm5k

The antenna in question was made for a variety of purposes. 2 meter, 440,
scanner,  test equipment and so on. It is adjustable to suit your frequency.
There is a loading coil in it, and the length does matter both below and
above.

If you only want an antenna for 2 meters, I would suggest you return this
one and order one from somewhere that sells what you "need". If it was
higher performance than the *** Duck, then I would suggest calling AES or
someone to order an antenna better suited to your needs.

I believe I still have the instructions for two (that I know of) different
models of those antennas that Radio Shack sold. Though basically the same,
if memory serves me correct without having to look at the instructions, I do
believe they were set for different lengths with regards to say - 2 meters.
So, if you want me to try to help you, you'll have to let me know the
catalog number of the antenna you have.

As stated earlier, the first section above the coil is retracted fully
to short out the coil. I then retracted the top section about 1/2 way. I
don't remember if I also retracted the bottom section completely or not.
Just measure for 19".

Hi, Lou.

Thanks for your follow-up post.

As mentioned in my first post when I started this thread, the RS catalogue
number for the antenna is 20-006.

However, I think I have the answers I need, now, from previous follow-ups.
As well, I just might go along with the suggestions and return this and
try to find a better one somewhere else (or even, perhap, roll my own).

Thanks for your willingness to help.

TNX ES 73,
Ed (VA3PU).

--
Ed Pugh           | "A common mistake that people make when trying
Ottawa (Richmond) | to design something completely foolproof, is to
Ontario, Canada   | underestimate the ingenuity of complete fools."
                  | - Douglas Noel Adams, 1952 - 2001 :-(

Hi, Mark.

Thanks for your follow-up.

[snip]

Quote:> 234 / freq is a quarter wave. But having a loading coil confuses this I
> would think.

What unit of measurement should this give?  Feet maybe?

The RS instructions said:

length in inches = 2834 / Freq in MHz.

For 2M this gives between 19.1" and 19.7" (depending on exact fequency).

Anyway, I think I have the answers I want.  A freind of mine has one
of those antenna measurement gizmos to measure the SWR and impedance,
so I guess I might get him to have a look at it for me.

TNX ES 73,
Ed (VA3PU).
--
Ed Pugh           | "A common mistake that people make when trying
Ottawa (Richmond) | to design something completely foolproof, is to
Ontario, Canada   | underestimate the ingenuity of complete fools."
                  | - Douglas Noel Adams, 1952 - 2001 :-(

David, I checked my antenna and found that if you fully extend it then
collapse the two sections just above the coil, the antenna will
measure 19" from the nylon insulator above the BNC connector.

Quote:>Does anybody have any experience using this antenna with the
>HTX-202?  If so, can you please fill me in on how to exactly
>configure the antenna?  (Maybe I should just return the
>antenna and try to get a better one somewhere else?)

I'd put that one to use on a scanner and pick up something along the
lines of an MFJ1710 for the 202.  My girlfriend's using my old HTX-200
(the itty-bity 200mw one) with the SMA jack yanked out and replaced
with a BNC so the 1710 would fit without an adapter, (ugly, ugly mod,
but it works, though you have to rip out a***anchor point, and the
case won't fit back together quite flush) and it can hit a couple of
repeaters downtown from our QTH in the northern suburbs.  (Plano,
Spring Creek and Custer.  It hits the W5FC and KA5CTN repeaters fairly
solidly, for those familiar with the Dallas area)

On my Kenwood D7A, I'm using a Comet ***ized whip that certainly
seems like the way to go it you're stuck with SMA.

OTOH, a field-portable groundplane antenna can, in most areas, turn a
5W HT into a respectable portable rig.  I'm having excellent luck with
the D7A on the simple SO239-and-brazing-rod groundplane from the ARRL
antenna book, using a foot of 5/32 brass tube with  another foot of
the rod crimped in as the radiator, so it's quite tunable.  The
disadvantage there is that it's also easy to detune when you're moving
it from place to place, but SWR meters are small, and tuning it again
is pretty quick.  With an easy-takedown homebrew PVC mast/stand, it's
the best portable 2m setup I've used.  The mast is about 5-6ft tall,
but the foot is small enough to put it on top of a picnic table or car
to give it enough height to be easily readable on a repeater I count
myself lucky to hit solidly on my 5/8wave mobile antenna without
cranking up the power.

Joe Bramblett, KD5NRH

http://www.redwaveradio.com/