What would be the best combination to cover that frequency range in
receive only? Would a 100 feet dipole with a discone cover it? Any
other suggestions? Thanks.
Mike.

On 22 Feb 2007 20:15:22 -0800, "ve2cjw" wrote:

What would be the best combination to cover that frequency range in
receive only?

A different antenna every octave: 11 antennas.

Would a 100 feet dipole with a discone cover it?

No.

Any
other suggestions?

See above. You could reasonably expect to skip the first 4 antennas
to cover the lowest frequencies.

73's
Richard Clark, KB7QHC

ve2cjw wrote:
What would be the best combination to cover that frequency range in
receive only? Would a 100 feet dipole with a discone cover it? Any
other suggestions? Thanks.
Mike.


Kind of like asking what is the best combination of qualities in a pet.

Depends on what you mean by "cover" and "best".

If you mean better than no antenna at all, then the dipole would
probably work, although it will be very directional at the higher
frequencies, and depending on the impedances involved, its response will
not be uniform across your target spectrum.

A vhf/uhf discone would be omnidirectional, but you said nothing about
the importance of directionality (in either the vertical or horizontal
planes) or of gain.

You have not mentioned whether any devices might be inserted between the
antenna and the receiver to effect a reasonable impedance match.

Inexpensive scanners often use a single (active) antenna to cover that
kind of range. In which parameters do you seek to improve on simple
scanner antennas? Sensitivity? Bandwidth? Directionality? Local noise
rejection?



Chuck
NT3G


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The idea is that I want to receive AM and shortwave broadcasts
probably using one antenna. Then, I need to be able to receive 144 mhz
and 440mhz in any direction including straight up for satellites, I am
talking about FM here plus the aviation band in AM. I also want to
receive some frequencies around 800mhz also omnidirectional. I will be
using all of these receive frequencies with an Icom IC-91A. I will
transmit on 144 and 440mhz FM using a Kenwood TM-G707A and a suitable
antenna depending if I want to access a repeater or a satellite. For
that, I have a dual band coaxial type of antenna and I will build
myself a couple of turnstile types for the FM satellites. I just
wanted to minimize the number of antennas I really need.
73 de VE2CJW
Mike.

ve2cjw wrote:
The idea is that I want to receive AM and shortwave broadcasts
probably using one antenna. Then, I need to be able to receive 144 mhz
and 440mhz in any direction including straight up for satellites, I am
talking about FM here plus the aviation band in AM. I also want to
receive some frequencies around 800mhz also omnidirectional. I will be
using all of these receive frequencies with an Icom IC-91A. I will
transmit on 144 and 440mhz FM using a Kenwood TM-G707A and a suitable
antenna depending if I want to access a repeater or a satellite. For
that, I have a dual band coaxial type of antenna and I will build
myself a couple of turnstile types for the FM satellites. I just
wanted to minimize the number of antennas I really need.
73 de VE2CJW
Mike.


Thanks for the additional information, Mike. For receiving MW and HF
broadcast stations, a random length of wire often suffices because these
stations tend to employ high power and directional antennas. You might
find that by making all or a portion of the antenna vertical, your
reception of distant stations is improved. An inverted L antenna is
favored by many SWLs. A google search on "SWL antenna" will provide you
with a lot of useful information on what others have used successfully.
I think a "tuner" or impedance matching circuit will be a useful
addition, especially now, at the bottom of the sunspot cycle.

For vhf/uhf omnidirectional reception, your suggestion of a discone
should work well, keeping in mind that it may not be suitable for
satellite reception in its usual orientation.

73,

Chuck
NT3G

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Thanks Chuck about the inverted L idea, I had never thought about that. What
would you recommend for satellite? Turnstile, eggbeater or something else?
Thanks again.
Mike.

"chuck" a écrit dans le message de news:
...
ve2cjw wrote:
The idea is that I want to receive AM and shortwave broadcasts
probably using one antenna. Then, I need to be able to receive 144 mhz
and 440mhz in any direction including straight up for satellites, I am
talking about FM here plus the aviation band in AM. I also want to
receive some frequencies around 800mhz also omnidirectional. I will be
using all of these receive frequencies with an Icom IC-91A. I will
transmit on 144 and 440mhz FM using a Kenwood TM-G707A and a suitable
antenna depending if I want to access a repeater or a satellite. For
that, I have a dual band coaxial type of antenna and I will build
myself a couple of turnstile types for the FM satellites. I just
wanted to minimize the number of antennas I really need.
73 de VE2CJW
Mike.


Thanks for the additional information, Mike. For receiving MW and HF
broadcast stations, a random length of wire often suffices because these
stations tend to employ high power and directional antennas. You might
find that by making all or a portion of the antenna vertical, your
reception of distant stations is improved. An inverted L antenna is
favored by many SWLs. A google search on "SWL antenna" will provide you
with a lot of useful information on what others have used successfully. I
think a "tuner" or impedance matching circuit will be a useful addition,
especially now, at the bottom of the sunspot cycle.

For vhf/uhf omnidirectional reception, your suggestion of a discone should
work well, keeping in mind that it may not be suitable for satellite
reception in its usual orientation.

73,

Chuck
NT3G

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"ve2cjw" wrote in message
ups.com...
What would be the best combination to cover that frequency range in
receive only? Would a 100 feet dipole with a discone cover it? Any
other suggestions? Thanks.
Mike.

A 100 foot dipole will work great on the broadcast band, and for receiving,
will be usable up to around 30 MHz. You will need at least 1 other antenna.
A 20 - 1000 MHz discone won't work very well, compared to a beam cut for a
particular frequency, but is probably the simplest way to go.

Tam