I have a Grundig YB-500 (Yacht Boy 500) shortwave portable. I frequently take it to remote locations with me and have enjoyed the radio for years. It has a short pull up whip antenna, all I have done in the past is to slingshot a long wire into a tree and use a clip lead to attach it to the pull-up whip (no external ant connections on the radio).

I was wondering what the impedance the collapsed whip would present, and what sort or a balun/auto-transformer could be used between a longwire (or other ant), gnd and the pull-up whip to improve reception...

.... anyone ever done any experimenting or unique ideas?

Warmest regards,
John C. Smith

--
Watching the cutting edge of yesterday replay--in virtual reality, right before my eyes--in real time!
Thirty year old technology--wasn't it amazing?

On Sat, 28 May 2005 20:35:59 -0700, "John Smith"
wrote:

This is a multi-part message in MIME format.
Boring.

I was wondering what the impedance the collapsed whip would present, and =

Hi Brett,

Depends on the frequency. EZNEC would answer that in a heartbeat.
Given your preference for backing into problem, at 10MHz, at 1M in
length, 1 - J 1Kohms.

what sort or a balun/auto-transformer could be used between a longwire =
(or other ant), gnd and the pull-up whip to improve reception...

Aw c'mon now, Google will give you this in another heartbeat.

... anyone ever done any experimenting or unique ideas?

Pons and Fleishman comes to mind - with many imitators....

73's
Richard Clark, KB7QHC

Hmmm, I have googled Richard... but not found anything other than standard baluns/auto-transformers and all too boring methods of using them... and yes, I could go expermenting on my own with these--was mainly hoping someone has walked this path before and already gleaned the best method, or at least could get me ranting, raving and thinking!!! grin My bark is MUCH worse than my bite yanno....

I didn't mean what the capacitve reactance of the pull-up whip was--itself, I meant to mean the input impedance which the input at the bottom of that whip expected to see...

It seems obivious they have provided some +J Ohms just past the bottom of that whip (or maybe not?)... however, input be high impedance and 1K+ ohms--and some non-reactive load could be assumed to be expected by it?

Warmest regards,
John

"Richard Clark" wrote in message ...
On Sat, 28 May 2005 20:35:59 -0700, "John Smith"
wrote:

This is a multi-part message in MIME format.
Boring.

I was wondering what the impedance the collapsed whip would present, and =

Hi Brett,

Depends on the frequency. EZNEC would answer that in a heartbeat.
Given your preference for backing into problem, at 10MHz, at 1M in
length, 1 - J 1Kohms.

what sort or a balun/auto-transformer could be used between a longwire =
(or other ant), gnd and the pull-up whip to improve reception...

Aw c'mon now, Google will give you this in another heartbeat.

... anyone ever done any experimenting or unique ideas?

Pons and Fleishman comes to mind - with many imitators....

73's
Richard Clark, KB7QHC

Well, leave it to me--said that all wrong and only caught it on the re-read--which--naturally--I did AFTER posting...

I should have made it apparent that whatever ant I hook to it, will, of course--have to mimic that capacitive reactance you mentioned...

Warmest regards,
John

"John Smith" wrote in message ...
Hmmm, I have googled Richard... but not found anything other than standard baluns/auto-transformers and all too boring methods of using them... and yes, I could go expermenting on my own with these--was mainly hoping someone has walked this path before and already gleaned the best method, or at least could get me ranting, raving and thinking!!! grin My bark is MUCH worse than my bite yanno....

I didn't mean what the capacitve reactance of the pull-up whip was--itself, I meant to mean the input impedance which the input at the bottom of that whip expected to see...

It seems obivious they have provided some +J Ohms just past the bottom of that whip (or maybe not?)... however, input be high impedance and 1K+ ohms--and some non-reactive load could be assumed to be expected by it?

Warmest regards,
John

"Richard Clark" wrote in message ...
On Sat, 28 May 2005 20:35:59 -0700, "John Smith"
wrote:

This is a multi-part message in MIME format.
Boring.

I was wondering what the impedance the collapsed whip would present, and =

Hi Brett,

Depends on the frequency. EZNEC would answer that in a heartbeat.
Given your preference for backing into problem, at 10MHz, at 1M in
length, 1 - J 1Kohms.

what sort or a balun/auto-transformer could be used between a longwire =
(or other ant), gnd and the pull-up whip to improve reception...

Aw c'mon now, Google will give you this in another heartbeat.

... anyone ever done any experimenting or unique ideas?

Pons and Fleishman comes to mind - with many imitators....

73's
Richard Clark, KB7QHC

On Sat, 28 May 2005 21:16:48 -0700, "John Smith"
wrote:

Well, leave it to me--said that all wrong and only caught it on the re-read--which--naturally--I did AFTER posting...

I should have made it apparent that whatever ant I hook to it, will, of course--have to mimic that capacitive reactance you mentioned...

Warmest regards,
John

"John Smith" wrote in message ...
Hmmm, I have googled Richard... but not found anything other than standard baluns/auto-transformers and all too boring methods of using them... and yes, I could go expermenting on my own with these--was mainly hoping someone has walked this path before and already gleaned the best method, or at least could get me ranting, raving and thinking!!! grin My bark is MUCH worse than my bite yanno....

I didn't mean what the capacitve reactance of the pull-up whip was--itself, I meant to mean the input impedance which the input at the bottom of that whip expected to see...

It seems obivious they have provided some +J Ohms just past the bottom of that whip (or maybe not?)... however, input be high impedance and 1K+ ohms--and some non-reactive load could be assumed to be expected by it?

Warmest regards,
John

"Richard Clark" wrote in message ...
On Sat, 28 May 2005 20:35:59 -0700, "John Smith"
wrote:

This is a multi-part message in MIME format.
Boring.

I was wondering what the impedance the collapsed whip would present, and =

Hi Brett,

Depends on the frequency. EZNEC would answer that in a heartbeat.
Given your preference for backing into problem, at 10MHz, at 1M in
length, 1 - J 1Kohms.

what sort or a balun/auto-transformer could be used between a longwire =
(or other ant), gnd and the pull-up whip to improve reception...

Aw c'mon now, Google will give you this in another heartbeat.

... anyone ever done any experimenting or unique ideas?

Pons and Fleishman comes to mind - with many imitators....

73's
Richard Clark, KB7QHC

On Sat, 28 May 2005 21:16:48 -0700, "John Smith"
wrote:
This is a multi-part message in MIME format.
This is still boring.

Well, leave it to me--said that all wrong and only caught it on the =
re-read--which--naturally--I did AFTER posting...

I should have made it apparent that whatever ant I hook to it, will, of =
course--have to mimic that capacitive reactance you mentioned...

And you had to post a 170 line message to pass on 4 lines of
information? This goes from boring to lazy.

The capacitive reactance comes free with the whip.

You will drum up a 100 responses on what's better - what is odder is
that all those great ideas haven't become ordinary after 50 years or
more. And after, what, 17 - 18 years? no one's figured out how to
power NYC with a Zippo's full of cold fusion either. Strange thing
about invention - doesn't seem to work all the time (or worse,
anytime).

73's
Richard Clark, KB7QHC

Sorry to disappoint you John.

Nobody has ever made a significant improvement using aligator clips,
lengths of wire and baluns on a portable whip receiver. Except, if
lucky, merely by chance on one band at the expense of the others.

You may, however, hear a bunch of claims, e.g., by CB-ers and
plagiarising old-wives, based on imagination and wishful thinking.

Signal to noise ratio is what matters. And that's an uncontrollable
function of the incoming signals and noise. the ionosphere, and of the
receiver itself.

However, it's quite interesting to experiment with longer antennas.
Obtain a circuit diagram of the receiver and try to predict what will
happen - if anything.

A most elementary circuit analysis is all that's needed. Otherwise you
will be working entirely in the dark.

Clear your head and forget about a balun. You must have been reading
the wrong magazines articles. You are dealing with an
unbalanced-to-unbalanced, very high impedance-to-high impedance
situation.

Consider a ground conection to the receiver chassis. This lowers the
impedance to more predictable values. OK if you are located
conveniently near to a domestic plumbing system. But even a short rod
in good soil will have some effect for either better or worse.

If you insist, signal to noise ratio MIGHT be improved by using a
single adjustable LC tuned circuit as a pre-selector in conjunction
with a length of wire and a ground connection of some sort. But it
might have an adverse effect.

My guess is that you will end up with a new, Japanese, very expensive,
battery-operated, communications-grade receiver at the end of a
100-feet length of 18-gauge magnet wire. Even if the wire is just
strewn on the ground.

Wait a bit and Chinese, equally good, 1/2-price versions may become
available.

Economics provide the foundations of all engineering. If you don't
understand economics then you don't understand anything. Not even SWR
or the portion of a dipole from which most of the radiation is
supposed to occur.
----
Regards, Reg.

JS,

On Sat, 28 May 2005 21:16:48 -0700, "John Smith"
wrote:


This is a multi-part message in MIME format.
Boring.

Whatever Brett did to his posting apparatus, the text now falls off
the right edge of the screen (in an Agent reader), requiring back and
forth scrolling to read anything.

bob
k5qwg

That is why I top post, so I can ignore the house cleaning...
Now, if there were a setting somewhere in this cheap M$ product which said something like, "Include no more that ??? lines of previous posts in reply..."--I'd use it! grin

Yes Richard, I still have not given up--perhaps there are people comming up with fresh ideas--even when I can't...

Warmest regards
John

"Richard Clark" wrote in message ...
On Sat, 28 May 2005 21:16:48 -0700, "John Smith"
wrote:
This is a multi-part message in MIME format.
This is still boring.

Well, leave it to me--said that all wrong and only caught it on the =
re-read--which--naturally--I did AFTER posting...

I should have made it apparent that whatever ant I hook to it, will, of =
course--have to mimic that capacitive reactance you mentioned...

And you had to post a 170 line message to pass on 4 lines of
information? This goes from boring to lazy.

The capacitive reactance comes free with the whip.

You will drum up a 100 responses on what's better - what is odder is
that all those great ideas haven't become ordinary after 50 years or
more. And after, what, 17 - 18 years? no one's figured out how to
power NYC with a Zippo's full of cold fusion either. Strange thing
about invention - doesn't seem to work all the time (or worse,
anytime).

73's
Richard Clark, KB7QHC