1/4 wave or 1/2 wve ground plane antenna

[DaddyHam]

1/4 wave or 1/2 wave ground plane antenna

I've got an SDR coming for xmas (yea) and will be building this 2M 1/4 ground plane antenna. https://www.youtube.com/watch?v=HkmD3Sgz7Q0

But I want a 70CM and 1.25 M antenna as well. Any reason these can't be 1/2 wave antennas? This will be my first antenna build.


Receive only. I won't be using these for transmit.

Thanks
Eric

 

[popnokick]

We need a little more info to make better recommendations.
- What frequency range(s) will you be receiving on your SDR?
- Is there a reason you are limiting the SDR to an antenna tuned mainly for 2M?
- Do you plan to transmit on both 70cm and 1.25M or only receive?

A 1/4 wave ground plane antenna will also work on 70cm (but not 1.25M). 1/2 wave antennas do not require a ground plane, and will actually not perform well if you attempt to construct one in the same manner as a 1/4 wave. So let us know more about what you plan to do and you'll get some more suggestions in this thread.

 

[DaddyHam]

@popnokick

Okay thanks. I want to start out at UHF and VHF and have ordered the AirSpy R2. The Airspy states

24 – 1800 MHz

Airspy R2 Hardware | airspy.com

I was going to do the 2 MEter to get experience building an antenna. But an antenna that will receive more bands would be great.

The reason for starting with UHF and VHF is I have a 3 band HT from keywood. So I can get to know those bands from a scanning listening standpoint.

I have antenna restrictions in my HOA but I will be listening on the 2nd floor and do have some attic space as well. Thinking starting simply and moving up from there.

Your help is appreciated

 

[popnokick]

I have an SDR and a couple of scanners. I connect all of them to this antenna that sits in my attic:
Homebrewed Off-Center Fed Dipole - The RadioReference Wiki
It covers nearly all of the freq range you'll want to listen to and is very inexpensive. The wire version (scroll down the Wiki page) costs even less and can be put together in 15 minutes. There are a TON of favorable reviews / threads and more detailed user reports right here on RadioReference. Just use the RR Search function and search for "OCFD" or "homebrewed" or "off center fed dipole.

You will not be transmitting with the scanner OCFD. But you can put antennas for the bands you want to transmit on in our attic. If you enjoy putting together your own, look at 2M / 70cm J-poles. And of course there are many 144 / 440 mHz dual band antennas that will fit in the attic as well. Keep them distant from the OCFD.

 

[DaddyHam]

@popnokick

Thanks so much.

That looks easy to build and will fit in my attic.

Eric