How quickly can an antenna be switched?

[Camerart]

Hi,
I have an idea, and the first thing is to find out about antenna switching, to see if it is a possibillity.

If 2x radios are connected to 1x antenna through a switcher, 1x of the radios is transmitting and the other receiving. How quickly can the antenna be switched between these 2x radios?

Cheers, Camerart.

 

[a417]

Hi,
I have an idea, and the first thing is to find out about antenna switching, to see if it is a possibillity.

If 2x radios are connected to 1x antenna through a switcher, 1x of the radios is transmitting and the other receiving. How quickly can the antenna be switched between these 2x radios?

Cheers, Camerart.

...as fast as the switch can switch them. Be advised that switches like this will ground the unused port, meaning that RX will suffer if that is what you were needing it to do.

 

[Camerart]

...as fast as the switch can switch them. Be advised that switches like this will ground the unused port, meaning that RX will suffer if that is what you were needing it to do.

Hi A,
I am thinking about speeds fater than the human ear, 'say' >20kHz.

I haven't thought it through yet, as this is the first step, but, a bit like a stereo system but instead of left and right, TX and RX.

I understand the need for grounding the unused port, but if another safety feature ?? was added, could this be possible?
C.

 

[WA0CBW]

Maybe more important would be how fast can you turn the transmitter on and off.
BB

 

[mmckenna]

You should probably read up on PIN diodes used for antenna switching:

https://qsl.net/n9zia/wireless/pdf/an929.pdf

Outside my experience, but I'm sure there is someone here that can help.

Answer: Very fast.

 

[Hit_Factor]

Balance the answer you find with the cost and other aspects of installing a second antenna.

 

[popnokick]

Reads to me like a job for a duplexer rather than a switch. What am I missing here?

 

[prcguy]

Most electrical RF relays switch in the 50ms time frame which is pretty fast. This would be the Dow Key or any other brand external RF relay that runs off AC or DC power or the PC mount types on circuit boards inside your radio or external power amplifier.

 

[Camerart]

Maybe more important would be how fast can you turn the transmitter on and off.
BB

Hi W,
Both radios will be on all of the time, so no switching there.
C

Balance the answer you find with the cost and other aspects of installing a second antenna.

Hi H,
I'm hoping this won't be necessary.
C

Hi,
In answer to the other replies. Once I'm sure the switching is possible, then I'll move onto how and with what, thanks.
c

 

[a417]

Hi A,
I am thinking about speeds fater than the human ear, 'say' >20kHz.

I haven't thought it through yet, as this is the first step, but, a bit like a stereo system but instead of left and right, TX and RX.

So...you want to change the signal path to alternate between TX & RX radios on 1 antenna at speeds greater than 20,000 / second?

What am I missing here?

same thing I am.

 

[mmckenna]

same thing I am.

I'm curious to see what his plan is.
Wondering if it's anything like DMR single frequency repeat?

 

[Camerart]

So...you want to change the signal path to alternate between TX & RX radios on 1 antenna at speeds greater than 20,000 / second?



same thing I am.

Hi P and A,
Yes, that is correct.
You're not missing anything.
C

 

[Camerart]

I'm curious to see what his plan is.
Wondering if it's anything like DMR single frequency repeat?

Hi m,
I'm not being secrative, just going through my initial thoughts one by one.

Remember I haven't though this through, and am working as I usually do. Here's an outline of what it's about.

A kind of relay net between operators, where each operator, could relay messages between operators that are out of range of others. The net I use a couple of times a week, talk among members, but some can't 'hear' others, so this will fill holes. A bit like the internet, but using radio instead of computers.

If switching as above is possible, then the next question may be is this legal?

C.

 

[mmckenna]

That's what I figured.

Nothing wrong with that. That's part of the hobby, experiment, try new ideas, do things different. Doesn't matter if someone tried it before and it failed, try again, maybe you'll figure it out. Ham radio is the place to try out new ideas and do things a bit outside the box.

Would like to know a bit more about your idea.

 

[Camerart]

That's what I figured.

Nothing wrong with that. That's part of the hobby, experiment, try new ideas, do things different. Doesn't matter if someone tried it before and it failed, try again, maybe you'll figure it out. Ham radio is the place to try out new ideas and do things a bit outside the box.

Would like to know a bit more about your idea.

Hi M,
Would like to know a bit more about your idea.
Yes, I'm sure this will all have been tried before, but if I have an idea, I don't like to know too much about what has been tried before, in case it knocks me off a new concept, and I don't like to go too far before checking the basics first, so one step at a time.

1/ Switching the antenna, as above.
2/ The legalities within our licence.
C.

 

[paulears]

A semiconductor switch works at nearly the speed of light - the delay comes from the actuating circuit. I don't know what you are doing bit maybe a circulator might be an alternative, depending on what you're doing?

Think about radar - Kilo/MEGAWatt power going out as a pulse, isolated from the receiver expecting microVolts back! Pulse repetition can vary a lot, but the receiver needs to be activated immediately the pulse has gone out, and minimum range for some radars is a few miles - that's a very short time!

 

[Camerart]

A semiconductor switch works at nearly the speed of light - the delay comes from the actuating circuit. I don't know what you are doing bit maybe a circulator might be an alternative, depending on what you're doing?

Think about radar - Kilo/MEGAWatt power going out as a pulse, isolated from the receiver expecting microVolts back! Pulse repetition can vary a lot, but the receiver needs to be activated immediately the pulse has gone out, and minimum range for some radars is a few miles - that's a very short time!

Hi P,
but the receiver needs to be activated immediately the pulse has gone out Both radios will be on all of the time, unless, not a good system.

I did a short explanation #13.
C.

 

[mmckenna]

Hi P,
but the receiver needs to be activated immediately the pulse has gone out Both radios will be on all of the time, unless, not a good system.

I did a short explanation #13.
C.

I think you need to give us more details. I read your explanation, but it's not enough to really tell us what the plan is.
A circulator, like Paulears said, might be a better solution since they can allow a receiver and transmitter to run at the same time if set up correctly, no switching involved.

 

[Camerart]

I think you need to give us more details. I read your explanation, but it's not enough to really tell us what the plan is.
A circulator, like Paulears said, might be a better solution since they can allow a receiver and transmitter to run at the same time if set up correctly, no switching involved.

Hi M,
There's not much more to it than my explanation in No 13. It's simply to connect hams on a net that have poor signals, through another on the net.

I don't know what a a circulator is.

I was talking to a mate who said, as you said that maybe DMR repeat may do, I also have no knowledge of that either.

I thought it may be possible to work through this idea in steps, but it appears not.
C

 

[mmckenna]

I thought it may be possible to work through this idea in steps, but it appears not.
C

It probably is, but I don't think we're completely understanding your scenario.

How is this different from a repeater?
How will this be utilized?
Is this voice or data?
VHF/UHF or HF?