I am trying to find/build a simple antenna to transmit in the 20-30 MHz
range. I have an HP RF signal generator with an N-type RF output
connection. I purchased an antenna from RadioShack but it only goes
down to 121 MHz for transmitting.

On the receiving end I have a scanner. I looked up info online for
building a zip antenna for receiving (I take it the built-in antenna
with my scanner, a Realistic Pro-2021, will not be adequate), but I
can't find any simple info on the best way to construct a simple Tx
antenna for 20-30 MHz that I can plug into my RF signal generator. Any
advice?

In case you are curious as to what I'm doing, I'm using the signal
generator to send out sine wave audio tones to various frequencies (as
in the Spiricom experiments), and have been successful at frequencies
above 121 MHz, but I don't have an antenna that goes below that
frequency.

Thanks in advance for any help.

PS I was able to pick up 121+ MHz frequencies on my scanner with the
built-in antenna even though I had to constantly readjust my Tx antenna
to transmit at various frequencies. Why did my scanner pick up those
frequencies without me having to readjust the antenna length, and will
a SWR with its own antenna be sufficient for picking up any SW signals
I transmit, or do I still need to build a receiving antenna?

grav

On 9 Aug 2006 12:37:14 -0700, wrote:

I am trying to find/build a simple antenna to transmit in the 20-30 MHz
range. I have an HP RF signal generator with an N-type RF output
connection. I purchased an antenna from RadioShack but it only goes
down to 121 MHz for transmitting.

On the receiving end I have a scanner. I looked up info online for
building a zip antenna for receiving (I take it the built-in antenna
with my scanner, a Realistic Pro-2021, will not be adequate), but I
can't find any simple info on the best way to construct a simple Tx
antenna for 20-30 MHz that I can plug into my RF signal generator. Any
advice?

In case you are curious as to what I'm doing, I'm using the signal
generator to send out sine wave audio tones to various frequencies (as
in the Spiricom experiments), and have been successful at frequencies
above 121 MHz, but I don't have an antenna that goes below that
frequency.

Thanks in advance for any help.

PS I was able to pick up 121+ MHz frequencies on my scanner with the
built-in antenna even though I had to constantly readjust my Tx antenna
to transmit at various frequencies. Why did my scanner pick up those
frequencies without me having to readjust the antenna length, and will
a SWR with its own antenna be sufficient for picking up any SW signals
I transmit, or do I still need to build a receiving antenna?

grav
http://www.cebik.com/a10/ant41.html

wrote:
Any advice?

CB antenna, good buddy. 10-4.

wrote in
ups.com:

I am trying to find/build a simple antenna to transmit in the 20-30 MHz
range. I have an HP RF signal generator with an N-type RF output
connection. I purchased an antenna from RadioShack but it only goes
down to 121 MHz for transmitting.

On the receiving end I have a scanner. I looked up info online for
building a zip antenna for receiving (I take it the built-in antenna
with my scanner, a Realistic Pro-2021, will not be adequate), but I
can't find any simple info on the best way to construct a simple Tx
antenna for 20-30 MHz that I can plug into my RF signal generator. Any
advice?

In case you are curious as to what I'm doing, I'm using the signal
generator to send out sine wave audio tones to various frequencies (as
in the Spiricom experiments), and have been successful at frequencies
above 121 MHz, but I don't have an antenna that goes below that
frequency.

Thanks in advance for any help.

PS I was able to pick up 121+ MHz frequencies on my scanner with the
built-in antenna even though I had to constantly readjust my Tx antenna
to transmit at various frequencies. Why did my scanner pick up those
frequencies without me having to readjust the antenna length, and will
a SWR with its own antenna be sufficient for picking up any SW signals
I transmit, or do I still need to build a receiving antenna?

grav


Try a dummy load with wires.

Try a dummy load with wires.


but make sure your SIG Gen. is a 50 ohm match.

Beloved Leader wrote:
wrote:
Any advice?

CB antenna, good buddy. 10-4.

So buying a CB, unhooking the antenna and connecting it to the signal
generator should do the trick? Seems too simple... any catches?

grav

Also, my scanner only goes down to 30 MHz. Since I will be transmitting
the signal from my rf sig gen to the receiving target in my own house,
will a simple SW radio work with its own built-in antenna?

Thanks for the input.

grav

On 10 Aug 2006 12:50:19 -0700, wrote:

Also, my scanner only goes down to 30 MHz. Since I will be transmitting
the signal from my rf sig gen to the receiving target in my own house,
will a simple SW radio work with its own built-in antenna?

Thanks for the input.

grav
What are you trying to prove?

wrote:
Beloved Leader wrote:
wrote:
Any advice?

CB antenna, good buddy. 10-4.

So buying a CB, unhooking the antenna and connecting it to the signal
generator should do the trick? Seems too simple... any catches?

Simpler than that. You don't need a CB (radio). All you need is a CB
radio antenna. Radio Shack et al. sell them for $20-30, or you can find
them at yard sales for a quarter.

I hope you are not transmitting on 121 MHz area. That is part of the
108 to 136 MHz aircraft band if I am not mistaken. 121.5 for instance
is an emergency frequency and it is monitored.

You will end up in the pokey for interfering with aeroplanes,,, watch out
they will call you a terrorist