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Old December 24th 09, 10:15 AM posted to rec.radio.amateur.antenna
Lostgallifreyan Lostgallifreyan is offline
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First recorded activity by RadioBanter: Sep 2006
Posts: 613
Default Sangean ATS-909 external antenna impedance??

Fred McKenzie wrote in
:

In article ,
Lostgallifreyan wrote:

Right now I have no idea what my favourite band might be. I'll try
the basic wire, I used to try that many years ago as a kid, in places
where it was easy, on private land with space for it. But that was the
seventies, in the country. Now I'm in an inner city full of mobile
phones and computers, things have changed so much that I know it won't
be the same. I like that 18' whip scheme you linked to though, I really
like that one and want to try it.


Lost-

I agree that the "basic wire" antenna approach will almost certainly
work. At least you will get your feet wet. That is the kind of
external antenna most often used with that type of radio.

If you want to continue the search for input impedance, consider trying
something like an MFJ Antenna Analyzer (MFJ-259 or 269?), which uses a
sufficiently low signal level that it shouldn't hurt the radio. Instead
of analyzing the antenna, use it to analyze the input of the radio. You
can use the information to design a matching circuit, but you may find
that the improvement is disappointing for reasons already discussed.

Fred
K4DII


I'll pass. I think the reason no-one knows is that as you (and others)
say, it's not important enough. What does seem important is to try to reduce
localised noise, and to break the current link to protect the radio input
from static discharges. Whether I use coax or a balanced loop made from
speaker wire, it loooks like my next step is to get Amidon FT-114-75 ferrite
cores to play with, and in Britain I can't easily do that, but if anyone
knows a local direct equivalent to them I can try that. I'll Google for
things that fit the description (AL about 3000, permeability u=5000, about
1.14 inch outside diameter) but I think it's wise to ask here to try to save
time.