Multiple antenna setup

[carlinm]

Hi everyone

I am new to the forum and setting up a CB base station at my home in Bonnyrigg Heights, Australia (Hey, what's that?)

I have an Anytone AT-5888UV dual band transceiver and want to connect both a 477MHz-tuned antenna and a 25-1300MHz discone or scanner antenna. Is this possible and what do I need to make the connection possible to the single antenna input on the transceiver.

Thanks in advance

 

[Shockwave]

The easy way out here would be a good coax switch. Combing the two on a single port transceiver is going to be hard since we'll assume you want the discone to be active above and below UHF low band. Most devices used to combine two antennas use a specific cutoff frequency where one port is tuned off and the other is activated.

You really need a combiner that has a bandbass filter on one port. The other port should have a bandcut filter on it otherwise when you combine both antennas on UHF low band, one could fight the other if they are not in perfect phase with each other. Since they are different antennas, phasing is not just a simple matter of coax length.

 

[carlinm]

Thanks for the advice.

The switch would not allow me to monitor both channels at the same time. I will investigate further on the filters.

 

[W5LZ]

If you will only be monitoring then almost any antenna will work. If transmitting on one 'channel' or the other, then an antenna for that band would be the 'best' choice. If a 'dual band' antenna is available for you two bands of choice then that would be nice. And then you have separate antennas for each band of use.
It amounts to just monitoring/listening doesn't require any 'special' antenna, anything works most of the time.
Nothing 'new' in this...
- 'Doc

 

[carlinm]

Thanks for the advice given. In the end I went with a wideband RX antenna and a TX antenna for the required frequency. I will use a coax switch to select the required antenna.

My next question is, where should I put the coax switch in the setup. Should I do Switch/SWR meter/Radio or SWR meter/Switch/Radio.

Thanks
Michael

 

[027andrew]

Hi there, interesting thread. did you find that the anytone dual band radio worked well on tx 477MHz? some say the unit only does Rx on 477 and some say the noted expansion allows Tx on 477. Also how does the dual band work in terms of splatter for example does a 10MHz gap work IE- 476MHz in and 477MHz repeat or does the radio require a larger gap? how close can the input and repeat output be set to for the unit to work? what frequencies did you use sucessfully?

 

[222DBFL]

Just because you have a dual band radio doesn't necessarily mean you need 2 antennas or even a coax switch. A good discone antenna setup as high as possible will work just fine for both receive and transmit. Just make sure that the antenna you get is able to transmit on the frequencies you want. Receiving shouldn't be an issue as most discone antennas are wide banded anyways. But unless you have 2 seperate antenna ports on the radio there is really no need for s coax switch. You won't be able to monitor and transmit at the same time with a coax switch as you can only use one antenna at a time. Like I said, seems that the best option would be a good discone antenna or a dual band antenna that will work on the frequencies you want to use. JMHO's. Hope this helps a little. Have a good day!!

 

[027andrew]

Hi there, interesting thread. did you find that the anytone dual band radio worked well on tx 477MHz? some say the unit only does Rx on 477 and some say the noted expansion allows Tx on 477. Also how does the dual band work in terms of splatter for example does a 10MHz gap work IE- 476MHz in and 477MHz repeat or does the radio require a larger gap? how close can the input and repeat output be set to for the unit to work? what frequencies did you use sucessfully?

sorry i meant to type 467 in and 477 out.